 So hello everybody, my name is Kyle Freund and on behalf of Lucas, Nico and myself, I'd like to officially welcome you to the IOC 2021. And of course, as many of you know, this builds upon the very successful IOC 2019 in Hungary, and we hope we live up to the standard that was set there. I think this was originally going to be a live conference and we had lots of fun things prepared for you. Various obsidian sources and so forth but I think it's going to work out very well and we have really great program prepared for you. Some topics we're going to cover over the next three days include obsidian sourcing studies and archaeology. So that's divided up regionally so we will have some talks from all over the world. And theoretical methods with another theme of the conference, lithic and technological concerns and theoretical and cultural concerns. Of course, we're going to kick off today with a keynote speaker, Dr. Stephen Shackley and I'm really looking forward to that. I guess I'd like to start by thanking some of our sponsors that have really made this possible. The National Association for Obsidian Studies being one of them. The Society for Archaeological Sciences and far Western Anthropological Research Group and XRF lab. I have all been really great sponsors for this and helped us put it all together and made it possible. Hello, yes, thank you. My name is Nico Tripsovich of UC Berkeley Archaeological Research Facility. I'm the organizer of this meeting along with Lucas Martindale Johnson and Kyle Friend. I'd like to welcome you to this meeting with and begin with a land acknowledgement. We recognize that Berkeley sits on the territory of Huchin, the ancestral and unceded land of the Chochenyo speaking Muacma aloney people. Every member of the UC Berkeley community has benefited and continues to benefit from the use and occupation of this land since the institution's founding in 1968. So with that, I'd like to go ahead and introduce our keynote speaker. Professor emeritus Stephen Shackley is a highly regarded archaeological scientist whose 30 plus year career has spanned the fields of anthropology, archaeology, geology and museum studies. He was awarded the 2018 Frixell Award for his interdisciplinary research by the Society of American Archaeology. In addition to his long career at the University of California Berkeley, Dr. Shackley is also the former director of the NSF funded geoarcheological XRF laboratory and he continues to teach as an adjunct at the University of New Mexico, serving as director of a new geoarcheological XRF laboratory in Albuquerque. He received his BA and MA in anthropology and geological science at San Diego State University and his PhD in anthropology from Arizona State University. He came to Berkeley in 1990 as a research archaeologist at the Phoebe Hearst Museum of Anthropology before joining the faculty of the University of the University Department of Anthropology. Professor Shackley's main research focus has been on the American Southwest and he is the author of over 130 journal articles and book chapters as well as numerous technical reports. He has also published several prominent monographs and edited volumes including X-ray fluorescence spectrometry in geoarcheology in 2011, obsidian geology and archaeology in the North American Southwest 2005, and archaeological obsidian studies method and theory in 1998. He is perhaps best known for his work on obsidian characterization in the American Southwest where he has been on the forefront of elemental characterization studies using X-ray fluorescence spectrometry. In this capacity he has been a steady voice arguing for the importance of high quality scientific research in archaeology and geological sciences, particularly in the wake of increasing ease of access to complex portable technologies. In addition to a productive academic career, Shackley has extensive experience in museum creation and display, having curated exhibits at prominent museums throughout California and the American Southwest. He has also served on numerous committees and boards, including as president of the International Association of Obsidian Studies, the vice president of the Society for Archaeological Sciences, and associate editor for the journals, geoarcheology and archaeometry. We are honored to introduce Dr. Shackley as our keynote speaker today. Welcome Steve. Thank you. Thank you very much, Nico. After hearing that I do feel tired, as well as retired. So I want to kind of set the tone here. So first I want to thank the three musketeers for putting this thing together, because I know it can be a real pain, particularly since we have to do this by waving at each other, you know, across the, across the, across the miles. Let's see if I can show you this. This was in our local paper. Now take a look at it closely. I think it worked in Ireland for a year. I found that pretty interesting. Americans are just geographically ignorant. It's just pretty great. And they wouldn't publish my letter. This is in the local paper in Albuquerque. They wouldn't publish my letter again. No, they don't publish any of my letters. Okay. This is of course my particular view, and over 35 years. And of course everyone here knows that there's been significant changes in what we do in provenance studies that period of time, most of which I find to be amazing and wonderful. So I'm going to try and do this in 50 minutes so there's plenty of time to talk and ask questions and maybe come up with a few answers. So the first part of this is going to be a little bit tongue in cheek but maybe does have some utility in a way. Since I'm going to make fun of myself so I want to talk a little bit about my background. So we're going to talk a little bit more about how things have changed in our discipline over time. Because I started in the 70s, like Richard Burger did, a little different place. And when I got out of the service, those of you not from the US, don't know that combat veterans get something called the GI Bill, which is actually cash to go to college. I don't know why not go back to college. So that's what I did, although I chose geology in this case, and that worked out pretty good for me you can see this picture down here my senior State University ID that the cool geology student. And if you're a male geologist back then you had to have long hair, generally held back in a back behind you so that's the way it is so I don't look like that now. I chose when I went. I always hate it when people put these long lists up here but since I'm the plenary speaker I can do whatever I want so that's what I decided to do. So, so what's happened since the 2011 obsidian. The book came out through University of Arizona praise press. So, actually, as you'll see even always spent many years working on sources there's seven new sources or source groups that we discovered. And plus, for my Mexican colleagues that may be online here, 10 more archeologically identified in Sonora but not yet discovered. So we're working on that. I don't understand any of the complexity of the mugging that teal volcanic province sources. Why this might be important to others from other parts of the world is that a number of sources that have the same geochemistry, but a great distance apart from the same volcanic province and I think there's other areas I think of Georgia and the caucus and some others that are like that. So there's a more sites have been added to the analytical pool that's another reason I'm tired. 35,000 more artifacts and been added to the regional archaeological database, and the largest group comes from that late classic social network project. I mean 15,000 and 20,000 samples. And then one that most people don't know about the El Segundo project in northwest New Mexico, which is almost entirely early and middle archaic sites, there's 7,000 samples. And this increases the number in this time period by thousands. So we have Mills and Clark late our class social network project again, approaching 20,000 samples. And Nico mentioned this briefly, all lab reports between 85 and 2016. And he's hassled me to put the rest of them up on East scholarship.org and if you haven't taken a look at that. It's a great open access. A place to go to get almost anything that we at Berkeley have written, including all the garbage, the junk. And a continuing collaboration with my Russian colleagues headed by Ekaterina Kate during a cheva in the caucuses and she's going to give a couple of papers on this. I believe first thing tomorrow morning. And most of the work I do in my lab now on the Southwest is geological. Okay, so, since you've been talking a lot about Berkeley and this Berkeley thing I wanted to bring up a short history of Berkeley's relationship with obsidian provenance and XRS specifically. And while XRF wasn't the first thing. Excuse me Berkeley wasn't the first place to use XRF and obsidian studies. I know that hall wrote that 1960 paper on use of XRF and archaeology, but it was one of the first. And it's created this expansion. Over time, even before I got there in 1990. Bob Jack and Bob hyzer and my department department of anthropology, published the first XRF analysis new world of city, but I know the next year Carmichael and Jack published the chemical fingerprinting of acid volcanic rocks from a geological perspective. And the 70s and 80s. I don't know if either one of these guys are online now Tom Jackson knows as a student of Stanford Richard use it UC Davis, use the same instrument for Northern California city and provenance studies. And then after 1990 after finishing my PhD at ASU coming to Berkeley I use that same spectrum instrument to quantitatively reanalyze the North American Southwest sources. And in the 90s I purchased two spectrase quantum instruments from Intel replacing the spectrase 440 that died. And that was an interesting perspective of those that you've set up XRF themselves. And I'm trying to find the. The rowdy and peak with that took about two months. That was a real fun job. And then oh, oh five I think Nico mentioned this I received NSF sponsorship for eight years to purchase the thermo scientific context instrument training students and XRF and obsidian studies. And that's the same instrument that's all over the world now and been used tremendously I think that the instrument itself is not what's unique but I think the software is one of the best that I've ever used, certainly the easiest, particularly for training students. Okay I'm going to just throw this up here's a partial list of grad students and postdocs. Now mostly faculty, some of which are actually online right now. They were trained in the Berkeley XRS system. So, at least there's that. This is what the lab used to look like at Berkeley, long long gone. I want to talk a little bit about an instrument that a lot of people don't really realize was a Berkeley except for Carolyn certain who did most of registration work on this. And then Carmichael, a very prominent pathologist and geologist approached me to get this Phillips pw 2400 through NSF, which we did do. Yeah, I was a little bit reluctant because I go oh fellas, this is wavelength XRF great instrumental precision but it requires, you know it's going to be a destructive analysis. I received the instrument I found that there was a routine in there to to ratio to the Compton Scatter, as well as the brimstone. So I lucked out in that because the spectrase 440 was dead, it was gone. So that worked out pretty well. So a little bit more history on this. Nico can correct me now but I think that instrument is either completely defunct, or has been scrapped. I think it's gone. And one of the reasons is those of you that work on the geological side of what we're doing is that geologists, geology is pretty much left x-ray fluorescence spectrometry for ICP MS. Certainly because they just later really don't care about whether the analysis is destructive or not like we do. And so if you really look at it x-ray fluorescence spectrometry is spectrometry is in our hands now in archaeology. That's not completely true geologists still use it a bit but mainly it's us. Okay, I've talked about maybe I've talked about this a little bit too much is the importance of a database. And let's see if this works, because you don't have not seen mine. We did this yesterday and it worked pretty well. In 1996, I think Rob Tycott did it about the same time to set up a regional database for Northwest Mexico and the US Southwest on the obsidian sources and pick one here I'm going to return to this a little bit later. Let's try that. I'm going to talk a lot about the Hamas Mountains here so. Your screen is dark. Yes, it didn't come up this time. Nothing showing. Okay, what should I try. I'll try to resume. Okay, now where am I am I back at the first slide. Yes. Why did it work yesterday and not today. Who knows right. Okay. I'll just wave my arms you won't be able to see. So you can look at this and then all of the. I think I can say this all of the known sources in this region are available. raw data, mean and central tendency. Generally the analysis of the oxides as well as the traces are available to everyone and in fact, people that are right actually online right now. So those using portable XRF, use this data set to assign the source and it works quite well. Lee Panitch and Santa Clara University have experimented then he can determine source quite well from this, this data. Okay, so I'll leave that alone maybe what maybe we'll work next time. Okay, so a little more history on this when I. When I arrived at Arizona State University. Frank Bam was beginning a project called the cultural reservoir archaic project large cultural resource management project in central Arizona. And he hired me to do the lithic analysis. And then he said, Hey, you know you're one of those geology guys from California wanted, you know we've got quite a bit of a city in these middle archaic sites why don't you. You know go out there, and you could source quote unquote source all the subsidian. Okay well I'll do that I pretty much left geology in the late 70s because all the money was making money in archaeology. So I had done that so I started doing the research, and you can see the map on the left here. Those were the norms known sources of art archaeological or artifact quality of sitting at that time. So, another reason I'm tired is after 35 years. This is what it looks like on the right. Those that are circled in red are the most recent ones ones I was talking about that be more recent. And can you see my cursor. So tank mountains and saline or saline are going to figure prominently here in a little while. When I talk about the issues of similar chemistry. Okay, I think that's enough. One of our former students from Berkeley lead panic I mentioned earlier it's Santa Cruz and Antonio porcato. Who works for Ena and by California, have really done it tremendous amount of work in by California. I often get the question has, does obsidian has obsidian ever quote, moved across the Colorado River from this side, over to this side. The answer is after 35 years we've never seen. It just hasn't happened. The way I explain that, or explain it away is that there's plenty of adequate obsidian sources on both sides, so they really need to do that. It's not that there hasn't been any communication. I think that Sean Dolan is going to talk about the relationship between the Southwest and Mesoamerica coming up. Maybe tomorrow. So there's plenty of communication in this region, but not obsidian. And that's another question that people are dealing with throughout the world. And it's mainly today is going to be a bit more on the geological aspects of what we do and provenance, more so than the archaeological application there's plenty of those coming up. And if we look at it at the continental level, there's a couple of points that are we're talking about and most of you guys know this, but some of you might not. I'm getting into my teacher mode here. The first thing I want to point out is the thickness of the continental versus the oceanic crust. What's somewhat unique about the continental versus the oceanic crust is the proportion of silica that's within that. And as a rare event in volcanic rocks, if it wasn't, we wouldn't be talking right now, I mean it'd be available everywhere, trying to deal with social networking exchange group interaction all that stuff wouldn't be very easy. Would, or it wouldn't be something that we could use to explain that. In the case it's very rare and one of the reasons is that almost exclusively and there's some exceptions to that. Most relic extrusive events occur because a magma plume is moved up into the continental press from the upper mantle and remelted material I'm going to talk about a case in the southwest where was a large pre came here and granite basement that was and that's we think what's causing similar chemistry over a radius of 200 kilometers. So that's something to keep in mind. So there's two general eruptive events that can produce obsidian or I like last, and I was looking through some of the presentations are coming up and there's examples of both of these, and I'll show some from the North American countries. The fusive eruptions are the ones that most people think about lava domes and coolies coolies are essentially a small flow that's occurred from a lava dome complex. Relatively rare and the reason it is of course because in order for us and pathology to classify it as a rhyolite. Proportion of silicon dioxide has to be relatively high in this case, mainly over 70% 78% or more. There's exceptions to that but generally that's case. And of course you have to have quenching and I'll get to that moment. Explosive volcanism not everybody thinks about although I noticed that there's a few papers. They're dealing with looks like what might have been plenty on their subplenium events, of course, made for me for plenty of the younger who was lucky enough to see that the Suvious event killed everybody in her killing and pay and might do it again. And that part of Italy, depending on how fast they get out of there. And some of the city and producing events can exhibit both the fusive and explosive volcanism. Like for me the pre Mount Taylor that's the most Mexican that's the look, let's look at a few of these. I use this image up in the top which is from Richard Hughes and Bob Smith's paper 1993. Kind of illustrative of what this would look like a little eruption that did quench and created glass. And we got there a few weeks later a few months or a year or two later. Not too many look like this although there was a number of them in Southwest to do. So this would be very recent. If you get the conditions to create quenching a classic when the one I were to think about. Frank Skinner certainly familiar with this is in Yellowstone where the eruptive event occurred under continental glaciers. And when you have a two kilometer thick glacier, it's going to cool very rapidly, and it's certainly going to quench, but also can occur. From high wind events. If the event is small enough in order for it to cool rapidly that's another way. I also might interject here that to my knowledge, no one is is actually seeing an event that created obsidian. It's not just a late geologist named McDonald, who supposedly saw one in Ethiopia I think it might have been phantali, but he's gone. So, that also gives you an idea of how rare these events are compared to Hawaii, for instance, result eruptive events which are very common. So here is near and dear to Carolyn's heart, the Glass Mountain event and medicine like Highlands, Northern California we were talking about that earlier. This is a hell of a big event. And there's, there's boulders there over three meters in diameter. What's interesting here is that this is less than 1000 years old. Certainly environmental conditions that allowed this to occur. And this is one of those sources that's of great interest to geologists and pathologists to because of the character of the flow. The de vitrification that's occurred very rapidly, a whole variety of other things that are not generally of interest to us in archaeology. But this is a relatively unique event, not that these don't occur, something like this all over the world, but generally that's, it's pretty rare event. And parentetically, what Carolyn was working on under dissertation was that they rarely you very rarely use this obsidian for production of small by faces. It's almost all those very large by faces that were used in the Urocks, white deer skin dance. And in fact, I've napt this stuff a number of times, and it lends itself very well to percussion but not pressure. This is one I've worked on recently. It's another policy and it's very interesting about 2.2 to 2.5 million years ago this is old this is right on the San Andreas fault line near them, the US Mexican border and Imperial County. And of course, this is distributed throughout that region. Well, very recent. One that I'll spend a little bit of time on is the in the Hamas Mountains is the Cerro de Medio event by us Riley in northern New Mexico in the Hamas Mountains. This is biometrically the largest source in the North American Southwest. You can see those very large pieces. It's about 900,000 to about 1.2 million years old. And there's a video here and I want to hopefully this one's going to work it worked yesterday. And since it's YouTube we're probably going to get some, some damn advertisement first but let's see if work. So Nico let me know if this works. I did yesterday. Did it show up. Yeah, yes. Okay, I'm not going to. There's your ad. I'm not going to make you listen to the ad. The bias caldera is famous, famous, famous to volcanologists and geologists alike, because this is the place where the universal model of caldera formation and development was first devised by Bob Smith and Roy Bailey of the US geological survey back in the 1960s. I can designate the bias as a type, this guy's still alive with the dome, following subsidence with the structural dome. A type structure is the base model used to describe a concept. The bias caldera is used as that defining structure for all volcanic calderas in the world. The origin dome, like redondo P is a structural dome. When the caldera forms. It blows a big hole in the ground because you're evacuating 95 cubic miles of pyroclastic flows. What happens first is that the floor of the caldera collapses, and it fills in with some of the pyroclastic material. The magma body is still rising. It's less dense than surrounding cold country rock. And as it rises, it pushes the floor of the caldera up into the sky. And redondo peak is a result of that uplift of continued magma pressure from beneath. So when you look at the rocks, the geology of redondo peak, what you're looking at is uplifted. Bandal are tough that at one time was in filling the hole, but the magma body has pushed it up in the sky, and you see that it's broken into a multitude of faulted blocks. One of the beautiful things about bias is that all the features are so perfectly exposed. You have this symmetrical circular caldera. You have this. So, can you hear me. Okay, yes. So this is Gerald a radio and you get an idea of that size. And this is part of that large ring eruption that's very well preserved. And I would add that I spent quite a bit of time working on these sources up there. And I have met geology field camps from all over the world. Germany, Mexico, and certainly the US, because this is the type site for this kind of eruptive event. Centralized resurgent dome with a dramatic uplift, you have an almost a perfect ring of rhyolite domes that have erupted along the ring fracture zone. And so you can put all this together and create this model other calderas it's not as well expressed. And so it took the work of these two guys at this place to develop the model that became so universally accepted and used to this day. All right, so do I stop this share and do a new share to get back. Probably, let's see what happens when you close it. Right. Yeah. Is it good. Yes. Okay. So, the geologist that was speaking is Fraser Goff, a guy I've been collaborating with for about a decade now. We publish into Mexico geology bear her bri lights, and I do a lot of the oxide analysis for him in my lab. And you can see the cell Dometio dome complex here, and that size. Now, there's obsidian sources that we work with all over the world of this large but in the Southwest, this is one of the major sources. And relatively recent. Okay. Another one that's very important for those working over farther in the West is government mountain dome complex. When I got there in the 80s. You could still get nodule sizes, half as big as your car and now you're lucky to get one as big as a rock hammer, because unlike the bias caldera that's in a national park protection system. There's a bunch of forests and flint nappers of really mind the hell out of this thing, including me. All right, let's get a little bit earlier here into the knee gene. These are the same kind of a fuse of events. But you'll notice that in general, most of the original obsidian has a de vitrified into pearlite. What's important here, and these more recognized sources are all over the world, certainly is that the obsidian that's left was probably the most vitreous and the driest in that original event. And so the quality is very great. The nodule sizes generally are quite a bit smaller of course than in the paternity. It doesn't mean they weren't used. They were certainly used from the paleo Indian period in the, in the late Pleistocene all the way through the colonial period, and I'm sure that we can say this all over the world, the same thing. These are just some classic. All right, this one here at sand tanks. You notice that all the fertilization that's occurred with the remnant Americanites. And some of these are quite are quite large. This is at Antelope Creek and meal Creek in Western Mexico. I'll return to that a little bit later. Here are some other examples. Sand tanks again was it deals to allow a northern sonora, which is fairly recently discovered. I'll tell you a story about me and the quality of my field work. There's another source nearby called los videos appropriately for those of the Spanish speakers here. We, we discovered this in the 80s. And it's very excited about it. We came up to wash recorded that source. And within 200 kilometers where we were was this other source that remained an quote, an unknown to Steve Shackley for about two decades. So this goes to show you you got to look around. Okay, look, violent eruptive events events that can occur, produce obsidian. I use this one because everybody's familiar with this Mount St. Helens which of course is not Rila it was an anti state strata volcano but everybody smear with it. I'll have a video in a moment to show this. This is also the sequence of events in a collapse called era. During the planning phase and then the ring eruptions. Volcanic history in the Hamas Mountains began long before the Caldera farm. First eruptions occurred here more than 15 million years ago. And so much of what we see here behind us are the rocks that were produced by those earlier eruptions. Lava flows and layers of pumice and ash that accumulated on the landscape and built up the mountains before the vias caldera tore them down. Fast forwarding to approximately 1.6 and 1.2 million years ago, the vias caldera was the epicenter of two massive volcanic eruptions that left deposits several hundred feet deep in the surrounding area. The most recent eruption emitted an astounding 300 cubic kilometers of molten rock and debris before collapsing into the vacated magma chamber leaving a depression 12 miles wide that can be clearly seen from space. Well the type of eruptions that happen at the vias caldera are impossible to imagine. The ground probably shook for months. Earthquakes every day. There might have been smoking ground. But once the crack opened and the volcano really got going, it started with a blast. A huge huge crack of thunder magnified thousands or millions of times. The initial blast sent out a shockwave so powerful it compressed air to the temperature of between 400 and 500 degrees simultaneously leveling forests and incinerating trees. But that was just the beginning. Huge toxic steam clouds billowed from the volcano's mouth skyrocketing some 30 miles into the stratosphere. Within minutes chunks of pumice rained down. The column eventually collapsed under its own weight and crashed to earth sending superheated torrents of ash, steam and gas racing across the countryside at supersonic speeds and forming the dramatic maces of the bandolier tuff. Eruptions may have continued for weeks. Many of us remember the destruction rot when Mount St. Helens erupted in 1980. But scientists believe the eruptions of the Vias Caldera were up to 250 times more powerful. Amazingly, the Vias Caldera isn't even the largest caldera in the state. That title goes to a collection of calderas in southwestern New Mexico that are some of the biggest in the solar system. Debris carried aloft by the ash clouds can be confirmed as far east as Kansas, Oklahoma and Texas. And some scientists speculate ash may have reached the east coast. Well, let's believe the dust cloud would have blocked out the sun over much of the United States for years and altered the world's climate. This will happen again, perhaps not at the Vias, but at some other volcano here in the west. And when it does, it will truly stop life as we know it. So, this is another example of ash low tough eruption, called around the world often ignombrites, although ignombrites for me is when the tough is welded. This is not a welded tough, but anyway, you can see what we call obsidian lapeli and petroleum lapeli is generally those pirate class less than 64 millimeter so they can be larger. But generally that's the case here. This is it. Laura Mesa, Mount Taylor. Fraser got mentioned the band of their tough that was from the Serral Toledo eruptive event. And all of this upper member of the tough here is full of obsidian that was quenched as and that that video would have showed that graphically. As the ash low tough was occurring, it usually moves at supersonic speeds and any lava within it. If it the glass warmers are high enough silicon aluminum oxides, it will create obsidian. And I have an example from Russia coming up that you'll see from the caucuses are the same thing. Let's talk a bit about secondary deposit issues in our area and of course all over the world, and this eruptive event was so large that it through this ash low tough down into the proto Rio Grande, and you can find this obsidian all the way to Chihuahua. This is an example from the caucuses we published this in the iOS bulletin actually was I a cool or box on source in the caucuses. And this is pretty classic look. This is quite an advantage you can see, and where this guy is standing there's nodules like this, in part of the vitrified if you can see it. The nodules are quite large 78 centimeters so this is a an important way that obsidian is produced. What's important for us, and I'm going to talk about that in a few minutes is that this is courses very friable. It enters in the environment through erosion, and can be distributed over great distances. What's important. I'm going to spend a lot of time on this that the range of variability of obsidian sources around the world. Paralumnius and Peralcon are probably the two major classifications for while, while Canucks at least as far as obsidian is concerned that we can classify Peralcon obsidian. The most famous example is Pachuca in Mexico. The reason it's so green is because the, you see in these propellants, the proportion of iron is very high. The same thing those of you. There's not many historic archaeologists here but green bottle glass is green for that very same reason. Often in Peralcon glasses, zirconium is very high. The two regions where there's quite a bit of Peralcon is the Sierra Madre Occidental in northern Mexico, and of course the Great Rift Valley. Now, we don't usually think about total alkalis silica plots, and the work that we do, but recently a project in Northwest New Mexico, this has become valuable. Many of the projectile points are made from a whole variety of different volcanics, including something I never would have considered trachea basalt and basalt agandasite. But in that early archaic they were using it. Nobody really knew where these sources were. And by determining the rock type, we were able to go back to the geological mapping and find some of these sources. So this is another method that we can use. And I know I'm going to forget his name, the guy at Montreal. Sorry, I forgot his name, especially if he's here. But he's been doing this in Canada too. It's very useful. Okay, I want to spend a little bit of my time here. A few minutes talking about the role of secondary deposition, or what is an obsidian source. And I know many of you think about it. It's been a big deal for us in the Southwest, both in the Gila River system and the Rio Grande. So when I was running my field practice in archeological field camps in New Mexico in the 2000s, we began to collect the secondary deposits along obsidian along the Rio Grande. This exclusively comes from the Hamas sources, which I talked about earlier, and Mount Taylor over here, coming through the Rio Marco into the Rio Grande. And I often tell my students, and I'm a flint knapper to when you carry everything that you own on your back. So when you think about that, I drive a pickup around the Southwest, but when you carry everything in your back, back you're going to be pretty parsimonious about where you get raw materials. And if you can pick it up close to where you're living. In this case along the Rio Grande that's what you're going to do. But is it an issue of epiphanality. It could be from the primary source but it could be from the secondary deposits so what we did was we looked at 11 sites along the Rio Grande, and collected in six areas along 400 kilometer area in the Rio Grande, and to make a long story short. Indeed, the correlation between the mix of sources at various areas along the Rio Grande, and the sites that were nearby was almost one to one. So if you're making an argument where, where are they getting this. And we're all interested in exchange and group interaction I mean, and we have fun with our instruments. What you have to do is understand the past and explain social networking group interaction, and all of these different things. This is the kind of thing that you really have to do. So I'm just calling your attention to the, the issues of secondary deposition and keep that in mind. It's not always an issue one of the sources, the one that we saw exploding. And this is a video from the bias right light. That's fairly recent. The eruptive event wasn't very plenty and they're supplementing, and it didn't get outside of the caldera. So we don't find that in the Rio Grande so that if we find it in archaeological sites in this region. It's got to be from the primary source. I want to beat that to death. This is some of the caldera and pre caldera sources we've been working with. So there's eight million years of eruptive events that have been emptying into the Rio Grande and the proto Rio Grande. And by the way, that river, the Rio Grande is only about four million years old. So those of you familiar with Western North America know how active tectonically it is there. And that's another example. Okay, I bring up Graham Mord's paper all the time, mainly because I made students read this it probably hated it on the ease of sourcing artifacts and the difficulty of knowing prehistory. That's what we're really doing here. I mean it's fun to do the science and determine the source, but we're trying to know prehistory. Again, I'm. So we still I still have some issues in the Southwest. I'll give them back that to volcanic province study I'm going to bring up. Again, this is an issue of having sources that are not near each other with similar similar elemental composition. Also, I'm not going to talk about the autonomous mountains today, because I spent all that time trying to get this to work. So the elemental discrimination issues again, saline or saline a sonora versus tank mountains. And how we're dealing with this. Now the muggy and that teal volcanic province study has come up. And these of course are near Jean they're very early. And I'll say that as far as I know, the oldest dated artifact of city and in the world is one of them that we found here called that mountain that over 31 million. The reason that's an issue of course is obsidian as a disorder substances moving toward an order state through absorption of water and of course that's the basis of hydration. So it's not generally very old doesn't last very long geologically. So we were quite surprised to get that kind of day. But what we have here is over a radius about 200 kilometers a composition that is very similar. So again if you're interested in generating models of group interaction exchange, you damn well better be able to separate or discriminate these things so there's a number of ways to do it. So what we did is went to various granny agencies and decided to let's date these are they similar in age. That would make some sense. They asked isotopically different, are they the same. And what is their elemental composition, and which we did. Let's see if I want to go to the next. Yeah. So the first thing we did was date all of these. And in this volcanic province, you'll notice that the earliest dates are in the south, and it moves through this to the latest date so it's moving south to north, mainly because of tectonic processes and I'm not going to get into. And so that's fine so we know that. And about this time, I talked to a geologist, late geologists at UNM named Wolf Elston, we've been working out here for God 40 years or something. And he was convinced that there was a granite basement. And we've been working on underneath all of this. And so, all of these sources had been remelting that granite basin basement, a basement that probably has very similar composition over a large area. So let's see if indeed that that's the case. So this is, sorry. This is what we're dealing with here. And these two here. Mule mountains and not mountain are the ones that are the farthest apart of course, and the most similar elementally this is called the Murphy's law of obsidian provenance studies. You know this kind of stuff always happens. We were able to elementally separate it a little bit if you look at these numbers it's not very much with barium. And I throw barium out because only recently have portable extra instruments be able to get to 50 KV and do that and I believe that I was talking about the new broker that's can get to that either that are Matt, one of the two. And this makes a very big difference why is that. I don't want to spend a lot of time talking about incompatible elements but barium happens to have very high ionic charge and it has difficulty finding mineral hosts in the solid phases. It stays in that melt for a long time. So barium is very useful at least for us in Western North America discriminating sources. Just want to throw that out. And of course in the laboratory XR even able to do that for a long time. And this this plot here makes isotope geochemists just grind their teeth whenever you plot age against isotopic composition but it works very well for us. Okay, and that's what we did here. I'm running out of time to stay online. Okay, another two sources that are as you can see here are great distance apart, have very similar elemental chemistry, at least in the mid Zs. And again here is barium that really helps discriminate these. So if you're working in the Southwest, and you're only able to analyze the mid Z elements, you can be in trouble. And these are this this one here and this source and sonora is distributed over a very large area well into above the border. So it's important to be able to do that. Okay. Final thought we'll see if I'm going to be able to do this. So in regards to whether your data are acquired through PXR effort lab XR effort ICMS or any whatever it is. I think we're in dire need of international city and database. Now some of you work in a relatively small region, you're using whatever it is you're using analyze the portables or lab XRF, and you don't worry about this but there are crazy people out there like me that work, work with this data all over the world. And if I am for instance, I'm somebody sending me something from the caucuses. And it's very difficult to fair it out the data on those sources. And I think I'm not going to do this but somebody here needs to do this, we need to have an international database. We've just done a great job in the Americans, putting that together, at least North America. But we need to have need to have not only physical description of the source and the bibliography, but also the raw data. Lucas was talking about publishing also, I think peak and background intensities and error. That's, I haven't done that, just publish the outside and ppm values but. And mean and simple tendency, including minimum maximum maximum really helps you assign the source it does me. Now I'm going to try this and see if we can do it again. So if I want to go to my website. Alright, so this is what I've done, and probably a lot of you seen this thing. You can click on this which one I want to go to. And of course that, having the images that's great to, but this is what we really need. Now I also analyze the major oxides to values plots. Maps of the location of sources that comes as the source composition you've seen this before this kind of thing. That's got a cow canyon. You're really good be helpful to have something like this. This is what I'm talking about is providing the mean intent and central tendency, especially minimum maximum you know what the range is at least that ability, and a number of people in North America with portable X or F and been able to use these data and assign the source. Yeah, I know right Lucas. I know, I know that Matt's done it. A whole variety of people have done it. As far as I know as long as you have a good understanding of your calibration and maybe even some scans of some standards. Yeah, okay that's a secret. Yeah Lucas that's the secret word standards. Jesus, come on you guys analyze the same standards, at least international standards so you can go and compare it. There are some differences between the results from the broker and my laboratory X or F, but if you look at the analysis. I use RGM one a lot or IGM two. You can standardize the data. And it works quite well. The simple thing so I've been lecturing enough, and I'm going to stop. Okay, I'm going to stop share. And anybody that has, let's see how much time we got, we got about seven minutes. Okay, are there any questions are preferably answers. If not everybody go to the bathroom or go have some coffee. Steve, I have a quick question. And this is more on the archaeology side in particular, whether there was any control over the territory, where these obsidian sources were that might have affected the actual use coming from different places. Yeah, that's a really good question. There is one great example of that in Arizona. There was more about 80 1300 I think this is what you're asking. There was a source superior picket post mountain that was used throughout the region. After about 1300 when with the rise of what's called Salado, which we all argue about whether really exist or not. It was territorially circumscribed and was no longer available. That's a really good example of that I think that's what you're talking about isn't it Rob. Yeah, I'm sure you probably have the same kind of thing in the Mediterranean. Does that make sense. Yeah, you're shaking your head. All right, well, thank you Steve. That was a really wonderful talk and inspiring how much information you put on your website, more regions have that kind of detail on their sources and the country. That's why I'm tired. So, I'm sorry about. It was funny yesterday we tried this and everything worked fine and now it's somewhere. Yeah, we'll help others have more luck. All right, well, Well, thank you very much. Yeah. Thank you. Yeah, thanks. No beer though. Well, people you'll be around if people have further questions right we can catch you on a in between other talks maybe. Well, let's get the landscaper's here and they have some questions for me so I'll be back in a few minutes. Okay, great. Thanks again Steve. All right, well let's go ahead and begin with our first talk of the session. Today we have, we're beginning with the chat on the obsidian source and its role in the pre-Hispanic exchange networks of the city kaka basin, presented by Richard Berger, Martin Gueso, Vanessa Jimenez, Bob Goldstein and Michael glasscock. Richard here with us I know. Welcome. Hi. Can everyone see this. Yeah. Yeah. There we are. Well, thank you for the invitation to come and it's my pleasure to be here and speak on behalf of the group of people that were just mentioned. In the 1970s, 846 obsidian artifacts from 98 archaeological sites, improving Bolivia or analyze that Lawrence Berkeley lab with Frank Isaro and Helen Michael in a pilot project that was designed to provide foundations for the study of obsidian trade and exchange in the ancient central Andes. The results were published in 1977 at LBL and also in Peru, and permitted the identification of eight compositional groups or types from Peru and northern Bolivia. And at the time, none of these eight compositional groups could be linked to geological sources of obsidian. But in the following three decades, seven of these eight compositional groups were successfully matched with obsidian deposits located in the southern highlands of Peru. And one of these, the key species saw source, the alka source, and the device source accounted for most of the artifacts. In the report of the results from Lawrence, it was acknowledged that the geographical distribution and sampling of obsidian artifacts in the study was uneven and unsystematic. But it was really quite likely that additional sources existed above and beyond the eight originally identified. And reflecting this reservation, 12 obsidian artifacts that didn't fit into any of the eight original compositional groups were analyzed by neutron activation. Their trace element abundances were published in the LBL publication as rare types one to eight. And it was suggested that some of these rare types could come from sources that were important in antiquity, but were scarce in the sample that had been looked at. And then not much happened for about 20 years. But 20 years later, I did some research with Sergio and Karen Chavez along with Frank Sorrow, looking at a large sample from the Lake Titicaca area and Cusco. And I found that there were a substantial number of artifacts that match what we call the rare type one. And they were especially common at a site called Tumuku, and we began calling this the Tumuku type. And based on the number of sites where these Tumuku type artifacts were located. We suggested that in fact, the source was probably located somewhere near the border between Peru, Bolivia, and Chile. And because of the frequency at the Tramacda pre ceramic site as well as the Tumuku site and here's Lake Titicaca, for those of you who are unfamiliar. Shortly after that, Martin Gueso launched a study of obsidian recovered from the famous site of Tiawanaco and related Bolivian sites. And he identified additional chemical groups, three of which were matched the geological sources in Bolivia. And one of the compositional groups that initially he didn't have a source location for, and was particularly common at the conco Juan Cane site in Bolivia. So he began calling it the conco type. In this talk, I'm going to present evidence of an obsidian deposit referred here as the Cherania source that matches the chemical composition of both the Tumuku type, or our rare type one and the conco obsidian type. It's located as expected in Bolivia near the border with Peru and Chile, although the distribution of the material from the source was not extensive. It has a history of exploitation that spans over three millennia. Our sample of obsidian artifacts from the Cherania source remains small but the available evidence suggests the exchangeable kind of glass from the source increase during the middle horizon, the period when this region was dominated by the Tiawanaco culture. In 2007, Vanessa Jimenez, then a student of archaeology at the Universidad Nacional de San Andreas La Paz identified the Cherania source while doing a regional survey for her licenciaturas thesis. The geological source labeled PAM 16 in her survey, which you can see down here. It's located at 3998 meters above sea level in the Marca Nasa Valley, 14 kilometers east of the town of Cherania. I'm in the province of Paca, his department of La Paz. The site is located in the high grasslands in the headwaters of the Mallory Valley. And in this region, there exists a variety of raw materials that were used in pre Hispanic mid times for napping including obsidian church Chalcedony the salt Jasper day site and Opal. The geology of this region is characterized by neogene magnetism, but I'm not going to really go into the detail in the into the geology. At the upper most level, there's a layer of Raya light and it's adjacent to a volcano, which is called the Seric volcano and a French group that studied the local geology thinks that the obsidian may have been produced by the eruption of that feature. The tyrannosaurus is situated on an arid plateau between the Marca Nasa and can you valleys, small obsidian nodules are scattered over the surface for approximately half a heck there. The tyrannosaurus obsidian is dark gray to black and appears translucent or opaque. Most of the nodules are small and rounded usually less than five centimeters in length. An example of unworked modules was collected and it at the locus and then it was taken to the Missouri research reactor for compositional analysis. Jimenez located 24 sites in our archaeological survey of Bolivia's Western Cordillera and obsidian was widely used for artifacts at these sites and enters survey to recover. Many flakes and small projectile points. About 9.5 kilometers from the tyrannosaurus near the juncture of two rivers was the site of PAM 10. This archaeological site covers about a hectare and a half. The residential camp where lithic production took place at 3962 meters above sea level. It seems to be slightly warmer area, and it's covered with debris suggesting abundance stone tool manufacturer. Here the stone nodules that had been brought there were no larger than three centimeters. The obsidian artifacts in the study. We're submitted to the mirror archaeometry lab at different times between 1992 and 2005. The geological samples from Turania were submitted in 2009. All the artifacts and geological samples were analyzed by neutron activation analysis using procedures that Mike Lascaucas described elsewhere. Now, some of you may know Mike and I want to show this picture. What's remarkable, particularly in light of the previous talk is that when we compared MERS results with the results from Berkeley that had been done almost half a century earlier. They provided almost a perfect match between our rare one or the tamuku type and the Turania source which shows you here this piece of information had languished for 50 years without any apparent use, but now it turned out to be important. The unique composition of the Turania source relative to other sources in the region is illustrated by a plot of the elements cesium versus half neum that you see here. But several other elements, such as manganese rubidium and also support difference between Turania and other sources. The red plot that you see shows the artifacts analyzed in MERS and Lawrence projected against the 90% confidence ellipse from the Turania source as derived from the 10 geological specimens analyzed and confirmed that the tamuku type artifacts are in fact from Turania. These are the conco artifacts that had been analyzed by Martin Jesus. The identification of the Turania source permits a preliminary review of its distribution prior to the Spanish conquest and a consideration of the implications of this patterning. As noted, the Turania source obsidian appears as nodules scattered across land surface, none of them larger than five centimeters on the side. This would have limited their utility for the production of large obsidian artifacts, but the nodules still would have been appropriate for making flakes and small tools. The size of the Turania nodules is in stark contract to the blocks, large blocks of high quality obsidian found at the Chavae source in Arraquipas Colca Valley. Not surprisingly obsidian from the Chavae deposit was heavily exploited throughout pre Hispanic times, and it was the dominant type of obsidian used in the Titi Kaka basin, including in Tioanaka. Nonetheless, despite its intrinsic limitations, Turania obsidian was utilized beginning in pre ceramic times and continued to be used for several millennia. Unfortunately, at present time the relatively small number of obsidian artifacts analyzed from the southern Titi Kaka basin limits our understanding but some tentative conclusions or discussion at least can be offered. In our sample 29 artifacts recovered from seven sites in Peru and Bolivia were made of obsidian from the Turania source. Three of these sites are pre ceramic in date. One is formative in date. One is early intermediate period in date and two others date to the middle horizon. The Turania source was exploited despite the size of its small obsidian nodules, located in the high grasslands near the upper level of agriculture. This geologic deposit was initially utilized by hunters and gatherers in the zone immediately surrounding the source. And then by agro-pastoralists who combined their herding of domesticated chameleons, yamas and alpacas with the farming of high end altitude and being crops. Obsidian was collected from the surface in the form of nodules. And at least increased ceramic times it was then transported to nearby locations, such as the rock shelter PAM 10 in order to be worked. The high quality of the Turania source obsidian, which is free of bubbles cracks and inclusions was appropriate for producing sharp edge flakes and small tools including projectile points. Like other minor obsidian sources in the central Andes, such as the Pusilana source in Ayacucho, the Lisa Wacho in Potrero Pampa, sources in Aparimac, and the Akonkawa source in Puno. Obsidian sources characterized by small obsidian nodules were generally of local importance with a restricted range of distribution. Even the Makusani source in the northern Titicaca basin had a range of no more than 120 kilometers, despite the exceptional visual attractiveness of its obsidian. In the case of the Turania source, before the middle horizon, its utilization seems to have been limited to the Alpiplano of the southern Titicaca basin with a distribution of between 120 and 140 kilometers. At the pre-ceramic sites, Turania artifactual obsidian appears primarily in the form of flakes and by faces, such as knives and projectile points. The flakes were probably used for butchering, scraping and cheering while the by faces were probably used for hunting and interpersonal violence. Pre-Hispanic hunters and herders preferred to make their obsidian tools from larger nodules of volcanic glass, and consequently they made the extra effort to acquire it from the major source at Javai, where blocks of obsidian sometimes measured up to 30 centimeters on the side. At late pre-ceramic and formative settlements like Kel Katani in the headwaters of the Asmori drainage, the occupants acquired most of their obsidian, some 77% from the Javai source in the Colca valley, despite the proximity of the Turania source. So the Javai is 250 kilometers away versus the Turania source, which is only 60 kilometers away. The pattern of augmenting or replacing the small local obsidian source with obsidian from a major source continued unchanged after chameleon herding in high altitude agriculture came to fully dominate the Altiplana. Although minor obsidian sources such as the Turania source did not play a central role in the regional pattern of trade and exchange, the sourcing of volcanic glass can provide insights into the movements and social relationships of the inhabitants of the people living in the Turania area, where today a border exists between Bolivia Peru and Chile. If pre-Hispanic people from this zone traveled beyond their homeland for exchange kinship obligations, or other purposes, it would be expected that traces of their short term presence might be left in the form of small amounts of obsidian debitage or tool fragments, constituting less than 3% of the total obsidian assemblage. Viewing the occasional presence of rare obsidian pipes as an index of these kinds of ephemeral interactions or visits, rather than as part of a formal provisioning strategy, suggests alternative interpretations for the presence of a small number of obsidian artifacts from small sources. For example, in the case of the Tewanaco capital in Bolivia, Turania obsidian constitutes less than 2% of the obsidian found at the site. Its presence at a minor mound or settlement such as Moyukontu can be hypothesized as the result of pilgrims from the Turania zone or visitors to kin visiting the urban center. From this perspective, the emergence of a large civic ceremonial center such as Tewanaco would be understood as providing the rationale for Turania source obsidian to be carried beyond its normal restricted use area. The presence at Tewanaco of a dozen types of obsidian from different sources in Peru, Bolivia, and the borderland between Chile, Bolivia, and Argentina can be interpreted as a testament to the cosmopolitan character of that site rather than a reflection of a complex system of lithic procurement. If this perspective is adopted, how can we interpret the lack of Turania source obsidian in the central and northern Titicaca basin and its analogous absence in Arequipa and Cusco? Given the large samples of obsidian that have been analyzed from these regions, we do not think that the observed pattern is the result of inadequate sampling. It seems more likely that the Turania area was relatively isolated and had only weak of any social and economic ties to peoples residing in the central and northern Titicaca basin, Cusco and Arequipa. Given the pattern described, how should we interpret the obsidian and analyze for the middle horizon site of Omo in the Asmori Valley? Here's Omo over here. The Asmori Valley is over here. Turania is located over here. At the site of Omo in the Asmori Valley, 54% of the current sample analyzed comes from the Turania obsidian source, a lowland Tiwanaco provincial center located 170 kilometers from Turania. It's the only site outside of the Pune environment that has yielded evidence of volcanic glass from the Turania source. While at first blush, this predominance of Turania source obsidian appears to be an anomaly, it is in fact consistent with Paul Goldstein's interpretation of the site as being the result of a diaspora of diverse groups living in the Turanaco region and neighboring areas of the Altiplano. Tiwanaco culture pastoralists and agriculturalists settling in Omo continued to maintain their links with the related communities in the Altiplano. Sometimes in the form of Yama caravans connecting the high grasslands with the warmer climbs of the mid-coastal valleys. While the western Altiplano has thus far yielded little evidence of a Tiwanaco road system, the least cost path corridors for caravan routes between the Moquego Valley and Tiwanaco pass well to the north of the Turania source. After these circumstances, Moquego's provisioning with Turania obsidian took some effort suggesting an arrangement with partners in Turania perhaps in response to Omo's isolation from Tiwanaco's Chivain network. Obsidian from the Turania source could have been brought to households in Omo as gifts from relatives or friends coming from the Bolivian Altiplano within the context of Andean reciprocity or by pastoralists leading Yama caravans to the coast, opportunistically picking up exotic materials such as obsidian nodules for gifts or exchange items along the way. Well, thank you. That's it. Thank you Richard. We're running a little late here behind, but do we have any quick questions? We can hit Richard up with questions later. Okay. I have a few, Richard. Let's move ahead. With the next paper it's obsidian exchange among hunter-gatherers in northwestern Patagonia, presented by Fernando, Francietti, Clara, Ota, Ota, Ota, Ola, Laura Sargan and Miguel Giardina. I'm sure who's going to be presenting. Hello. Yes, we can. Thank you. Well, good morning or good afternoon. Please be patient with my accent. We present obsidian exchange among hunter-gatherers in northwestern Patagonia. In this graph, we observed that local raw materials such as basalt and crystal-piston were predominant in the Diamante Valley. As you can see here, the gray part of the graph showed samples from the highlands and in black from the pigment, and we observed very low proportions of obsidian in compared to the other raw materials. The goal of this paper is to assess the convenience and use of obsidian as discussing aspects of mobility and exchange within hunter-gatherers from the Diamante Valley where obsidian was relatively rare. And where research questions are, was obsidian acquired directly or indirectly? Can we interpret exchange from some obsidian sources? In this figure, we observe the three locations that represents highland villages and El Indigeno, the highlands with the site Perdido 1 and the pigment with unit 115. We also observe the obsidian sources identified in this work, Laguna del Diamante, Las Cargas, Maule 1, Maule 2, Coche Quemado, El Peseño 1 and 2. It is important to mention that during the late Holocene, for southern Mendoza, we have observed an intensification process with the broader diet breadth, an expansion of social networks, technological changes, such as the incorporation of ceramics. All these ideas are being understudied at the moment by our group. To explore the use of obsidian in the Diamante Valley, we propose two hypotheses, one of direct access to obsidian and other indirect access and therefore to exchange. For direct acquisition, we expect a source to have a high representation among the assemblies. All the stages of reduction sequence would be present, coarse, flakes, with and without cortex, flakes with age maintenance and tools. There will be high diversity of artifact types, for example, projected bones, side scrapers, scrapers, knives and vices. And we would observe abundant cores, high proportion of cortex and low resharpening of tools. For indirect acquisition, we expect a low frequency of a source present in the assemblies. We would observe only the final stages of the reduction sequence, with exalted cores, flakes without cortex, flakes with age maintenance and tools. Low diversity of artifact types and absent or exalted cores, also no cortex present and high resharpening of tools. We chemically analyze all the recover obsidian from the Diamante Valley with a size larger than 8 millimeters. The 180 obsidian sample include surface and stratigraphy assemblies. We use the XRF portable spectrometer from the University of Nevada, which Christopher Morgan brought to Mendoza. We only included variables from mid-Z elements, which can be detected with little background effect. We loaded the geochemical data into the freegal software. The ellipses were more clear when we worked samples at the level of their geological site. However, we present the ellipses graph with all the samples included. Here we show the map of Mendoza in the upper right with the obsidian sources. In the ellipses graph in yellow are samples from highland villages, in green samples from the highlands and in light blue samples from the bitmap. We could determine that 70% of the samples belongs to las cargas, 7% to el peseño 1, 4% to el peseño 2, 8% for cochequemado, 6% for el maule 1, and 2% for Laguna de Amant. And finally, 1% for el maule 2. From the central place of the basin, las cargas is around 150 kilometers per distance. It's the most abundant. In contrast, Laguna del Diamante is around 70 kilometers away, which is the closest source, and is the less abundant. The first prediction which relates direct acquisition with proximity did not meet. From the 180 analyzed samples in the Diamante basin, 58 had chronological association. Despite archaeological sites at the basin have chronologies from the Hurley Holocene, in this analysis we had only lake Holocene samples. We divided the sample in 500 years intervals during the last 2000 and 500 years before present to explore the variation in the use of sources through time. As expected, in a context of exchange, the number of exploited sources increased a long time. We observe that las cargas persists being the most used source and also increase its uses in later times. This might be because las cargas was the best quality source among the region in terms of sizes of cores and properties. It caused our attention that even during the last 1500 years, when the intensification process occurs, hunter-gatherers use other sources but still seem to prefer las cargas. We also explored trends in the relationship among sources and the use of space in different ecological zones. You can see here in the right the different images of the different environments. The Highland villages, which are located above 2,600 meters above sea level, the Highlands with an altitude between 2,000 and 2,900 meters above sea level and the Piedmont with an altitude between 1,000 and 1,900 meters above sea level. Las Cargas source is the most abundant in the three ecological zones showing again that there is no relationship between distance and abundance. We inspired part of our work in this amazing book and here we have a chapter from Kelly to 2011 who summarized the average maximum distance for logistical forest among different hunter-gatherers. He established that on average we could think of a 175 kilometer distance for these trips considering a travel rate of 40 kilometers per day. But this distance and travel rate might be considered an acceleration and therefore he also explored a radius of 88 kilometers considering a travel rate of 20 kilometers per day. Despite we know there are some groups with larger logistic trips, we use this logic to generate this ready for the Yamante Valley to the sources. This major circle in orange is the 175 kilometers radius and in yellow the 88 kilometer radius. If we consider the 175 kilometers radius, Laguna del Maule 1 and 2 and Cochequemado all outside the expected logistical forest zone. When we consider the 88 radius of the sources but Laguna del Yamante all outside the expected logistical forest zone and only Laguna del Yamante is in the circle. We must also consider that both ranges are accelerated when we add terrain constraints and time expended in hunting and securing subsistence during the trip. In some we consider that an embedded acquisition of logistical trips of obsidian was very unlikely. Therefore, we suggest that obsidian acquisition was product of conveyance through potential hoods visible in their least cost path analysis. In the pit moon, despite el peseño is a good quality source and is closer than las cargas, it presents very low percentages. Why do we observe this pattern? Which was the role of las cargas? Does this imply that the pit moon had higher reliability in the mobility year round pattern towards the highlands in the west in opposition to the east? This pattern may support the idea that las cargas had a direct access as we observed in the variables above, while the others sources had an indirect access. The least cost path from the highlands indicate all sources are 70 kilometers distance or more. This consolidates the idea of non-local availability of any of these sources. We observe a similar pattern than the one observed in the pit moon. However, we identified the presence of obsidian from Laguna del Yamante, the only source that has a path exclusively from the highlands. The access to the rest of the sources implies a path through the pit moon or the lowlands, suggesting that even the sources in the whole visera like las cargas and el maule 1 had access from lower altitude from these locations in the highlands. Therefore, we consider that even for many areas of the highlands, mostly those adjacent to the pit moon, there were paths that favor north south roads at lower altitudes. In a context of territoriality and enhance of exchange, this would imply that areas further south in the pit moon lowlands like Jancanelo or El Nevado may have been hotspots for exchange circulation nodes. We observe that only three sources were used in the highland villages, las cargas, coche quemado, and maule 1. The importance of las cargas may be explained by the access through a corridor and roads. In addition, this route from las cargas to Laguna del Yamante connects the four highland villages, Los Peucenes, Risco de los Indios, El Indígeno, and Laguna del Yamante located there. This route may have been a crucial node of exchange networks across the highlands with its implications to the complementary networks in the eastern side of the Andes. We may hypothesize that las cargas obsidian was acquired indirectly through El Indígeno or other highland villages, as the list cost path indicated that the shorter distance to las cargas from the Yamante valley is El Indígeno. It is probable that the groups from the pit moon and the highlands acquired obsidian from las cargas in El Indígeno. This notion may be reinforced by the presence of force from las cargas in El Indígeno and presence of projected points and bifaces in the highlands and the pit moon. In a context of high mobility and therefore for direct access to all the sources present, we would have expected that all sources had similar representation, showed similar plate sizes, variability, and diversity of certified types regardless of distance. This was not the pattern in the Yamante valley. Following the expectations, we observed that las cargas has direct access while the other sources have indirect access. Las cargas source, considered the best quality source is the most abundant, has higher artifact called class richness, present presence of all the reduction segments, higher variation coefficient for size, and higher frequency of force and core flakes. Closer sources should evidence higher frequencies, higher variability of sizes, some small force to be also present and high diversity of artifact types. In contrast to expectations, Laguna del Yamante did not show abundant frequencies in the Yamante valley. In a context of higher use of local raw materials, basalt and crystal-crystalline, the closest source Laguna del Yamante indicate legal use. Las cargas was the main source used and its importance increased in the late Holocene, despite the use of other sources. The use of obsidian in the Yamante valley, framed in mobility exchange routes, may find a model in the list cost analysis. However, hunter-gatherers surely follow the courses of water across an arid and altitude landscape, many times ignoring a straight-efficient line in a span that do not secure water. Also, these routes, and mainly for the occupations in the highlands or highland villages, accommodated to specific patches of resources where the gregarious populations of Guanacos travel in summer. Thank you so much. Do you have any questions for the speaker? An interesting place with a lot of types of obsidian, Fernando, looks like a great region for study. Thank you. Well, our next speaker is not able to be here, but she has provided a video, so I'm going to play her video. Pre-recorded. The talk is titled prehistoric use of an obsidian-rich, igneous-bright deposit northwestern Patagonia. And the authors are Raven Garvey, Ramira Barberino, Augustina Rudini, Victoria Fernandez, Guadalupe Romero Villanueva, and Brandy McDonald. Hi, I'm Raven Garvey. I regret that I couldn't attend the conference in real time, but my co-authors and I really appreciate the organizer's flexibility, which has allowed us to participate nonetheless. Since I'm not there to answer questions during the event, I provide my contact information here, and would welcome any feedback or questions that you might have. My email address will appear again on the final slide of this presentation. I'm presenting some preliminary results of a collaborative project with the co-authors you see listed here. These data relate to one of our primary goals when one of the things that motivates our ongoing research in northwestern Patagonia, which is to understand prehistoric use of the region's multiple obsidian sources, one of which is a vast obsidian-rich ignombrite deposit. I'll say more about this momentarily. To orient those perhaps unfamiliar with the region, Patagonia is roughly the area indicated by the yellow ellipse here, so southernmost South America. And this talk centers on northern Neuken province, Argentina. The study area extends from the Andes, which form the border between Chile and Argentina, down through a foothills and the Piedmont of the Andes, and eventually out onto an arid plain in the eastern part of the project area. The region is correspondingly ecologically diverse on account of this vertical arrangement of habitat types and also due to dramatic differences in precipitation caused in part by the Andes themselves. This was probably first inhabited around 11,000 years ago, and throughout the Holocene was home to relatively small and highly mobile groups of hunter-gatherers who subsisted primarily on Guanaco, which is a medium-bodied camelid. This is the Mesquite and eggs of Rea, which is an ostrich-sized, flightless bird, and a variety of plants including prosopis, which is a genus of legume that also includes North American Mesquite. This of course is an absurdly simplistic sketch of the region's prehistory, but it helps to set the stage anyway. Prior to this project, I worked a bit farther north in Mendoza province, also indicated on this map. It's similar in many ways to Nuquen, the basic geography, ecology, and that caricature of human prehistory that I just described. All of these things are fairly similar between the two regions, but the two provinces are different in important ways as well. Relevant here are differences in the distribution of Napapl stone, namely obsidian. There are several known sources in southern Mendoza province, and some of them were clearly important archaeologically given the abundance of obsidian in the region's archaeological sites. But there are other Napable volcanics in the region as well, and some crystal-cryptolin silicates besides. Currently speaking, one thing that I'm quite interested in is how stone availability and tool use interact to influence technological change. So in the context of the Mendoza project, I developed a microeconomic model of toolstone procurement. Here's the basic cost-benefit structure that the model assumes with time along the x-axis divided into production time to the right of the origin, and production here includes procurement and manufacturing. Now we have use time to the left of the origin. The y-axis represents returns, which is a term left deliberately ambiguous here to be specified as appropriate to a given study. Returns could include cutting edge per unit weight, for example, calories produced by a tool's use, or even social variables like prestige if a tool was used in virtual display, for example. These are two of the most commonly occurring stone types in archaeological records are obsidian and basalt. These differ in their nabability and in the quality of tools that can be produced from them, such that in many cases obsidian will provide higher return rates. And importantly, obsidian basalt also differ in their availability on the Mendoza landscape. Generally speaking, basalts are fairly ubiquitous in the surface geology, and so they're locally available relative to most sites. So their production time is less. The production time associated with salt, basalt tools is generally lower. Obsidians on the other hand are much more patchily distributed on the Mendoza landscape. The most commonly used ones, according to archaeological records, are located in the Andes, and they're really only seasonally available. These obsidian sources tend not to coincide, the ones in the Andes anyway, tend not to coincide spatially with the most abundant food resources. So obsidian procurement generally requires special trips to these distant sources. Even these characteristics, the relationship between obsidian basalt defines a critical use time indicated by the heavy black line here, and also there on the on the x axis. Any amount of use time beyond this critical threshold, the stone forager should choose obsidian. This is represented by the red dashed line here. The use of use time that is less than this critical use time would favor the use of lower quality but but ubiquitous basalt as depicted by the blue dashed line. And in fact the model's predictions are well supported by Mendoza's archaeological record, particularly through major climatic fluctuations that triggered behavioral reorganizations, and that's demonstrated in the publications that you see here. In fact, Mendoza province is Nukin, and the distribution of obsidian is really quite different there, making it a really attractive independent test case for for this model. Lake Mendoza Nukin is tectonically active and surveys over the last two decades have identified several sources of obsidian in the study area. We started with a shaded ellipse in this figure, indicating our it's showing our current best estimate of the extent of each of these sources. Each is fairly aerially extensive. You might note the scale bar there in the lower right hand corner for reference and I'll return to this point in just a minute. The materials were collected and analyzed at the Missouri research reactors archaeometry lab. We started with extra fluorescence to determine the chemical composition of the obsidian sources in the region, and quickly realize that further analysis was necessary to better differentiate the, the, the tangle of groups in the lower right corner of plot a. So the relevant samples underwent neutron activation analysis which was better able to differentiate those sources so we now have reasonable chemical characterizations of these sources. So a slide or two ago I noted the geographic extent of the new Ken sources. And this owes largely to geomorphic processes during the Lake quaternary, including the, the formation and subsequent catastrophic failure of natural earth and dams which redistributed materials across the landscape. It's also the case that one of the most archaeologically important sources in the region is actually an extensive pyroclastic deposit containing obsidian nodules. This is the serial when will source indicated on the map by the yellow lips. And this asphalt tough is not only naturally expansive on the landscape erosion of the matrix has produced matrix has produced lag concentrations of obsidian nodules and gullies and other erosional landforms and the fluvial systems that flow through the source through flow through this tough deposit, further transport obsidian nodules downstream. As this map also indicates serial in all obsidians are distributed across multiple altitudinal zones from about 2000 meters above sea level, which are the local uplands. And really only seasonally habitable by humans, and the source extends down to about 800 or so meters above seal and sea level which is the lowlands available year round. The interaction between geographic availability of when the city and prehistoric human ecology creates this highly complex macro regional obsidian quote source scape as we call it in the paper referenced here. The serial obsidian are subangular to sub rounded and they reach about 10 centimeters along the major axis. It's mostly black but there is some variation gray and brown and brown black banded types are also fairly common. But despite this this sort of these these cosmetic differences serial and will presents a pretty low chemical variation. These samples of this obsidian show some level of translucency generally lacks inclusions and the napping quality is is pretty, pretty consistently excellent. So thinking back to this procurement model now, given the near ubiquity of when will obsidian in some parts of our study region, we would predict it's it's procurement, even at relatively low levels of tool use. We would predict it's used to the near exclusion of other types of stone, as in Mendoza nappable basalts are common in the region in no can, but given the ready availability of obsidian, and its superiority for the production of particular kinds of tools. So for anything that you might need a sharp edge for for example, there are these obsidian tools are also more easily maintained their easily resharpened. So for these reasons, the, the, the, their, their return rates are generally considered in their, and the model essentially predicts that any difference in the procurement of obsidian versus basalt will owe to their having served different purposes, whereas in Mendoza, their procurement owed more to the costs associated with going to get them finding on the landscape and obtaining them. In this case, we might assume that differences in their use would owe to something more like preferences for particular tools say obsidian for slicing and piercing tools and basalt for chopping and pounding tools. So consistent with expectations, Sarah when will obsidian dominates both stratified and surface sites, accounting for 93% of the 1000 plus obsidian artifacts considered in in the regional studies cited here. Contrary to Mendoza that the interesting question in no can becomes not when will people use non local obsidian versus local basalt but instead how were people using this local highly local immediately local obsidian, or to rephrase the question, what governs obsidian use when procurement costs are effectively removed from the equation are so minimized as to be relatively unimportant. So the stratified sites in the region provides some preliminary clues here. First is a site called Quema one will sharing its name with the source. It's indicated here with the star. The window source is is again here indicated by the ellipse that you can see that the window site is located more or less within the window source. It may be a bit hard to tell on this map but a better one is is coming in one or two slides time, but Quema rule is in the lowlands at about 1000 meters above sea level lowlands in our study region considered between anything less than about 1200 meters above sea level, considered the lowlands, the intermediate zone then being between about 1200 and 1800 meters above sea level. So going to this general model of human biogeography that guides our research in the area. The lowlands are generally considered less attractive than this intermediate zone, primarily due to the relatively lower rainfall and correspondingly lower primary biomass. The expectation characteristic of the Arab lowlands is evident in these pictures. And you may be able to make out a stream channel in the top left picture but this is a dry channel. It runs only very rarely. This site was occupied occupied intermittently between about 11,000 years ago and late prehistory so so nearing contact with Europeans as predicted by the procurement model obsidian dominates the lithic assemblage and is set on a new type accounts for almost 95% of all obsidian here, which is not at all surprising, given its location within the source region. Interestingly though there are very few courticated pieces in the record suggesting primary reduction elsewhere. The tools are also very few in this assemblage and the use of local when will obsidian is is pretty expedient these this neither is this very surprising it's consistent with the ways that local student stone is used elsewhere in the world relatively more expediently that is. This cave site, several kilometers to the northwest of que when will provides an interesting contrast here. This cave was excavated pretty recently and many of these data are preliminary, but there are nonetheless some interesting patterns emerging. The star at the top left indicates the location location of Kueva shaggy. And you can probably get a better sense here. This map is color coded to distinguish highlands and red from intermediate zone in in orange and lowlands in yellow. Now you can perhaps see better that which is just to the east of the star it's that first green dot to the east of the star is located in the lowlands whereas yaggy is is in the intermediate zone at about 1400 meters above sea level. It's also along a permanent creek. So already there are some important differences between kept quiet yaggy and when will. There will be lower elevation and also a much drier habitat. So it's being in the intermediate zone affords access to resources of the adjacent highlands which are seasonable seasonal but seasonally abundant, and the lowland resources which are available year round but generally scarcer on the landscape. This site is is the site itself the feature is quite complex with an open shelter. But there's been a lot of late Holocene erosion causing lots of of calving of the rock face itself creating you can see those very large boulder piles and the image the the line drawing on the bottom there indicates the the full extent of the feature which is about 220 square meters of covered surface it may all have been a shelter at one time but part of it now is a cave on account of of considerable rockfall. Here you can see that that there is currently very little head room inside the cave excavation was was impeded in part by this it made more difficult anyway. We excavated I should have mentioned on the previous slide, you may have noted that there is a square between what is currently shelter and what is currently cave so right at that transition we excavated a test unit. You can see its location here in what we what we take to be a relatively undisturbed part of the cave but adjacent to what is likely looters pit you may be able to make out in that top photo. We went down an arbitrary 10 centimeter levels to about 150 centimeters below surface. The table at the top of this slide provides the first radio carbon dates that we have for the site. There is a noteworthy reversal between levels three and six and also a pronounced break in the radio carbon record between about 6000 and 2000 Cal BP. This is likely an erosional unconformity that some data indicate that it is, it is probably not an abandonment of this site. I don't think I'll have time to say more about that. In this presentation below the table largely for illustration is a corresponding projectile chronology that is emerging from this study. Surprisingly, the test unit produced quite a lot of obsidian not surprising, again, given its location within the when will source consistent with data from Quavo when will that also the broader regional sample mentioned earlier, about 85% of the 400 on pieces of obsidian analyzed from the site that we analyzed by using XRF are assignable to the to the when will source. This sample of when will obsidian we selected a sub sample of 100 artifacts for a battery of tests related to obsidian hydration. I won't be able to talk about most of those tests now, but but in the context of these radio carbon dates one of our objectives is to serve probe the radio carbon anomalies that are evident here. So we selected between five and eight samples from each of the 14 excavation levels. All of them assigned to the when will sources I mentioned, Dr. Chris Stevenson of Virginia Commonwealth University performed a density analysis to estimate intrinsic water. Those data show pretty good consistency across samples and will be building on those data going forward. So the first of orators obsidian laboratory in California first measured all hydration rooms optically using a 12.5 power filar filar micrometer I piece mounted on a polarizing microscope. We then selected a 5% sample for analysis by secondary ion mass spectrometry for independent very verification rather of the optical measurements. As you can see in the top panel here that there's, there's excellent convergence or excellent correspondence between the optical and Sims measurements, which gives us a high level of confidence in the other optical measurements. So it's also worth mentioning that only three of the 100 samples showed any signs of weathering. And there were 16 total that failed to yield reliable hydration measurement for for various reasons, but there was no meaningful temporal pattern associated with these with the among these 16. The expected hydration rooms show a general correspondence between thickness and age as illustrated in the bottom panel here. As is also evident in this figure, there's a fair bit of variation in room values particularly in the more superficial excavation levels so near the surface. There's a broad data that that went into those box plots showing showing this a bit more clearly at the red line at about two and a half microns marks the median hydration room value there's no statistical significance here but it serves to illustrate that levels six and above regularly deviate from expectations with lots of rooms that are larger than expected, while level seven and below contain fewer, fewer values that are smaller than expected. This could be due to post deposition or disturbance, particularly affecting later occupations but an alternative hypothesis that we're exploring now is scavenging scavenging or later use of materials discarded during previous occupations. The whole lithics analysis for this site is ongoing so unfortunately I don't have additional data to present in this regard but the relationship between mean hydration values for each level and the degree of variation among hydration values within each level is intriguing. This is illustrated here in that in the red box on top, which shows that as mean hydration values go up. That is, as we move into these into the earlier occupations lower in the in the excavation. The coefficient of variation goes down, that is rim variables are rim values are less variable earlier in time. This could be due to post deposition or disturbance but if that's the only force responsible for this pattern. The implication is some real sort of turning of these deposits to bring those pieces with high hydration values to the surface. There really isn't evidence of this in the in the stratigraphy so again the alternative hypothesis is that it reflects routine scavenging or later use of previously deposited materials. The idea being that the opportunistic use of materials already in the cave would keep larger rimmed materials near the surface and available for subsequent selection and use, creating the pattern of greater variation and rim values later in time. So we're exploring this now and and hope to have a better sense soon of what, what best explains this pattern. So, assuming back out to more general interpretations of prehistoric use of this vast obsidian rich ignombrite called Sarah one rule. Here's a comparison between Kueva shaggy and Kueva one rule that that first site that I mentioned, also within the window source area. There are notable differences in their lithic assemblages as you can see here at Kueva shaggy there are four more formal tools particularly projectile points and scrapers. Even despite the much smaller excavated volume, whereas Kueva one rule is dominated by expedient tools and debitage. But if the pattern of hydration room values at shaggy does reflect routine scavenging of obsidian this would be consistent with a rather more casual the use of when will obsidian that we would expect given it's that it's immediately local relative to the to the shaggy site. So going to have been scavenged it has to have been discarded initially with with some remaining usable life, which becomes less and less common, the more distant sites are from sources. So in trying to understand the economics of immediately local stone use we might explore the fractal nature of the stone procurement model, or the self similarity at different scales. Before we were considering landscape level distributions of stone types. Here we might consider distributions within an area that most, I think, would consider immediately local, you know within a kilometer from from the site so if there's usable obsidian beneath your feet at Kueva shaggy. There's relatively low cost associated with procurement, you might have to root around to find a piece of the right size and shape, but there's still likely to be a level of use, you know level of need beyond which it still warrants the trip to the source for deliberate procurement of the materials that will maximize returns. With that, we we thank the many agencies and people who supported this research. And on behalf of the research team, half of whom are pictured here at Kueva shaggy. I thank you for your attention. I welcome your feedback and your questions here again as my email address on the left hand side just above the M. So, so thank you, and I'll look forward to to your feedback. Let's move along to the final paper in the this morning. We have a 12,000 year sequence of human use of the Alka obsidian source in Peru with Kurt Rademacher, David Reed, Michael Blasscock and Bruce Kaiser. Hey Kurt. Hey Nico. Can you hear me okay. Sure can. Okay, great. So today's talk is going to be a two parter. First part is I want to tell you about the Alka obsidian source. And then the second part is I want to explore the human use of this source over a long period of time over 12,000 years. So what you're looking at or the screenshot you're looking at right now is a Google Earth image of the Alka one bedrock outcrop at a mountain called Cerro Condor Siana, at about 4,800 meters above sea level. And all those black areas you see there are our obsidian outcrops. So this is one of Peru's major obsidian sources as we heard. It's one of sort of the big three that provided lots of artifacts to, to societies throughout pre contact pre history. All three of these sources are located in the high end is above 4000 meters above sea level, and obsidians from all of these three sources were transferred extensively across the central Andes and archaeological sites that received obsidian sources are shown here in black triangles. I'm not the first person to work on Alka at all, a whole bunch of people have. And this again started with Richard Berger, he and his colleagues Frank Asaro and Mike Glasscock had identified artifacts of the Cusco site that were very numerous in the department of Cusco, east of where the source was eventually identified. But based on the spatial clustering of artifacts made from different chemical sources. Richard almost single handedly tracked down all of these bedrock outcrops throughout Peru. And one was brought that was brought to his attention was from a local townsperson who brought a big block of obsidian to cultural anthropologist working in this valley Paul Trey work with who I guess brought it to the attention of Richard. And Richard Mike Glasscock characterize that and realize that it matched the Cusco type of artifacts and so a follow up trip to the valley identified obsidian here where this red arrow is pointing. Following Richard's original publication of the source, Justin Jennings and Mike Glasscock together published on additional occurrences of obsidian in the in this valley. They identified more than one geochemical group these were called Alka X and Y. Nico trypsovich himself came here and mapped obsidian at Sarah icon, which I'll show you in just a bit. The Polish fellow Mikhail was a left ski was working in the area mostly east of here in the Valley of the volcanoes and found obsidian. He also visited the Alka Valley and collected an analyzed obsidian here with Mike Glasscock. And starting in 2004 I started working here in the Kota was he Valley, and then realized the Alka source was much bigger than than we had considered it. And he continued on trying to systematically map and characterize the Alka source till about 2015. When I first got started on this, I was started exploring east of the canyon where local towns people had informed us that there were much larger areas of obsidian, and within a pretty short walk from the town of Alka you get to see this this amazing area where I don't know if you'll be able to see my, my cursor but this talus cone here is is obsidian and volcanic ash that's raining down from the eroding. Rhyalite dome of Sarah Condor Siana. Here's in a Google aerial shot of that again. Again, this is what I showed you on the title slide, but the amount of obsidian here is enormous I've never seen anything like it. And, and large, large fragments and blocks of obsidian are eroding as bedrock, and also just appears there, it's being exfoliated from the surface by the erosion of fine material. Here's another Google Earth screenshot of a different area. This is a different Rhyalite dome that is being exfoliated, and this one's at higher elevation. This is south of Condor Siana. This one's called Navado Sappo, Havana, where a different geochemical group that we called Alka 2 is located. This one's above 5000 meters. And here's a third one called Cerro Icano, where, where the Alka 3 bedrock type is is our bedrock outcrops of the Alka 3 type are exposed here. Okay, so those are three of the Rhyalite domes with three different geochemical compositions. Those are here, Alka 1 in blue, Alka 2 in purple and Alka 3 in yellow. These are, these are clustered at the east rim of the Kota Wasi Valley, but, and these, these diamonds of different colors here are all the obsidian samples that our team has collected and analyzed throughout the years. We also found quite a lot of obsidian to the south in a different area called the Pocuncio Basin, this area here. And additional chemical groups are here as well, but Alka 1 obsidian is here, pyroclastic material, and, and then additionally, three other groups are here, Alka 4, Alka 5, and Alka 7. We originally identified a group called Alka 6, but it was within that Condorciana outcrop and not geographically different, so it was subsumed under the Alka 1 group. So in conclusion, oh, and I should mention there's pyroclastic material over here in the Andagua Valley that Mikhail Wasilevsky identified, and some up here as well. These match the, the groups that we've identified over here west of where he was working. So it seems that we have a collection of rhyolite domes. And we also have pyroclastic material that's distributed over 2000 square kilometers of this area of this area of the highlands, and it's especially exposed where erosion has has gone to work on on these, these deposits. There are six geochemically distinct subsources, and a variety of geochemical techniques differentiate them, including neutron activation analysis, wavelength and energy dispersive XRF and portable XRF. So, it took a while but neutron activation analysis is now fairly complete on all six of the Alka subsources. That's the plot in the upper left. In the lower right, portable XRF can also distinguish these same Alka subsources using the same samples and then all of the other samples that we've collected. When I started doing this, it was really an iterative process of exploring mapping obsidian coming back to the lab geochemically characterizing it and then going back to the field, trying to trying to make some sense of the patterns. Since I started doing this work. There's been some improvements in the bedrock mapping that's available in Peru. And when I we plot the two areas where obsidian is most common. We bring up some of the new geologic mapping we see that the obsidian clusters very beautifully in a couple of map formations. Obsidian is occurring outside of these formations. I believe it's because the geologic mapping is is a bit imprecise. So these formations are are referred to as the Senca or Arma formations and the terminology is Sean club through a has done some great work in this area that have has constrained the Alka of the deposits that seem to contain Alka obsidian to between 3.7 and 1.5 million years ago. Okay, what about human use of the Alka source. The source is actually local at a site called concha rock shelter. And here's a photo of the landscape that contains concha rock shelter it's right there in the cocoon show basin where all of this Alka obsidian is located. And in fact obsidian is available on the alluvial fan directly below the rock shelter, as well as in the in the basin as pyroclastic material. This is really remarkable for a lot of reasons I won't go into. But one of the ways that we've used it is that it has an amazing sequence intact sequence of stone tools, and because it's local to the Alka source and it has so many stone tools obsidian over. Over 1100 obsidian formal tools that we've analyzed, we can examine these of these, the pattern of use of obsidian through time. We don't have a sequence here, no site in this area is continuously occupied. We have sort of these windows in prehistory, and those are goes go back to about 12,000 years ago in the terminal Pleistocene, about 9000 years ago in the early Holocene, and about 6000 years ago in the late middle Holocene, and then within the last 4000 years or so. I just want to walk you through what those major patterns are showing. And I'm only going to talk about projectile points and these next four slides. I'm setting aside other kinds of stone tools made of obsidian projectile points are numerous and they tell a pretty neat story. So here we are at the terminal Pleistocene use of the Alka source here at Conchaica rock shelter. We see the presence of all of the obsidians that occur within the Pocuncio basin so these are all local obsidians that could be foraged within the normal day to sustain food and other resources around the Conchaica rock shelter. But we also see a predominance of the Alka for obsidian subsource and the Alka for subsources here located some distance. Why are why is more obsidian made from this more low more distant source was we've seen in some other talks today. We have obsidian here that this is a bedrock outcrop so the size of the obsidians larger, it's there in more, more quantity, and you can make anything you want out of it as long as you're willing to go for a walk. So it seems that that was worth it for these folks. I've seen it shifts a little bit. So the major shift is that we see a great increase in the amount of Alka one. Now I'll go one does occur locally in the basin and it has been used previously in the terminal Pleistocene. But I can't explain it's it's increased in this amount in any other way other than I think these people have discovered by this time condor say on a bedrock outcrop up here to the north. And that's the reason I can think of why there why the obsidian and what this type would increase. If that's true. It would imply a 66 kilometer round trip mostly above 5000 meters above sea level to go and obtain that material. In the late Middle Holocene. We see another interesting evolution, where the locally foraged obsidians the Alka five, the Alka seven those drop out. And now we see exclusive use of both bedrock outcrops, Alka one and Alka four, and that pattern only remains the same and maybe a strengthen in the late Holocene. Within the last 4000 years, where we see near exclusive exclusive use of those, but especially focusing in on this Alka one outcrop which is the biggest outcrop of all in the whole region. The size of obsidian and the quality is amazing as well. Okay, so that's the local story, but we also have this kind of interesting non local story right from the start, the Pocuncho basin on this on the plateau where I've been telling you about concha is the source of these obsidians the only place where these three obsidians are together, but obsidian also occurs almost at the same time at the coast about 150 kilometers away at a site called Gibraltar Hagwai. And Gibraltar Hagwai was originally thought to date to about 13,000 years ago, predating concha rock shelter in the highlands, and is often used to suggest that perhaps there was a coastal migration first, and that people moved into the afterwards. Work by our team has showed has shown that the coastal site is actually not earlier than the highland site. In fact, it might be a bit later, or we can't tell them apart. Maybe there are different groups of people living in each area, but at any rate, Alka obsidian has come down to the coast, right from the start at this site Gibraltar Hagwai. And it's coming down in various sub sources. West of Cape Rata Hagwai 42 additional sites at a place called Papa Colorado show a sustained presence of Alka obsidian throughout throughout the early and middle Holocene to about 5500 years ago. In fact, most of the the formal tools at this coastal area, even though there are local materials raw materials that are suitable. Most of the materials used for stone tools in this area are obsidian, and they come from the Alka source, Alka for Alka one Alka five and Alka seven all come down to Papa Colorado with the closest Alka subsource Alka for this one here, comprising the majority of the of the stone tools. These are these are patterns that hunter gatherers are responsible for, but we can come even more, even closer to now. And let's look at the end of the pre ceramic period this is pre pottery, and into the beginning of complex societies in the Andean region. This is also a time period when we see domestic camelids coming on the scene and Yama caravan starting up maybe. And if we look at the distribution of obsidian and Peru we see that that Alka one obsidian becomes quite widespread. It goes far beyond its source region. It's transferred over about 1000 kilometers up here to northern Peru at this time. This is before any state society is around. If we look at the early horizon when when we see some early complexity appearing we see even more of this pattern, where we start to see other Alka subsources going away from the source region such as Alka five. This is the middle horizon. This is the period where the Wari Empire is expanding and the Wari Empire is really interesting on this time period the middle horizon is very interesting in the Andes because this is when obsidian distribution really goes really goes haywire. Obsidian is going all over the place from all kinds of sources. And so we can look at how Alka figures into this by looking at this little area in the red box that my co-author here has has done a really interesting study. So this is the area called the Mahes Valley which is just to the south of the Alka source. And in this area. David has excavated two kinds of sites. One are sites that the Wari state seem to be responsible for their really complex sites, lots of architecture and very distinctive architecture that relates to the Wari specifically. And then there are these local caravan way stations. These are simpler sites that appear to not have so much of a Wari administrative footprint in them. And David analyzing over 300 artifacts of obsidian here has also and also the Alka subsource geologic material has been able to look at the different use patterns in obsidian here. So the Wari state sites have almost have an exclusive use of the two bedrock outcrops from the plateau, the local bedrock outcrops. The caravan way stations have this amazingly, a much more diverse obsidian profile with local material still comprising the majority of what's here. But material from very far away from a whole bunch of different sites in central and northern north central Peru are appearing here as well. And David thinks this is because long distance Yama caravans are coming in and bringing all of this obsidian to these sites. Going finally ending with the late horizons is Inca times when when people are really, really familiar with, with Peru. We, we continue to see Alka subsources moving away, including to a site called Yama Wilka that that Steve Shackley published on. So it's an interesting story of Alka subsources and, and, and analysis of larger artifacts sets by portable x-ray fluorescence is part of what's allowed us to see with this increased resolution, the, the evolution of behaviors, starting from the long distance gathers and long distance social connections, then moving probably to Yama caravans carrying obsidian far and wide along and across the Andes. And finally, states getting involved and seeing a very different kind of pattern when states are involved in the distribution of obsidians versus what when those states are not involved. And I just want to thank everybody for setting up this meeting and for inviting our team to present our work to you. Thank you Kurt over 10 minutes over time but we're going into the lunch now so we can presumably chat with Kurt and those of you who go to lunch will be resuming at 1pm Pacific time. So, I'd like to ask you a question Kurt. Is that data from my head is that in David dissertation. Is that available. Yes David, David, are you here. He was here. Yeah, there he is. Yeah, yeah, so that's in the dissertation soon to be submitted for publication. Thanks for sharing that here. So that's great that you're able to, to pick apart the different uses with all the sub sources. That's really interesting. And most of the Indian sources don't seem to at least central and he's done seem to have so many sub sources. I don't know why that is. I'm somebody who's smarter than me needs to speak up but maybe I, yeah, I don't know why that would be but it is interesting. I mean, the Yelma Erkins did work at the COSA source looking at the, you know, usefulness of sub sources and to archaeology to investigations and, you know, I wonder if maybe at Alka there was there was a series of extrusion events, you know, and Thorez data might answer some of that like how the timing works out for the different sub sources. So great, great papers. I actually had a question I was chatting with Dave about earlier and so maybe Richard and Kurt might help clear this up. Dave was telling me there's a bit of an overlap in at least PXRF values for Chiranya and Alka five. And I'm just wondering without higher resolution techniques, how we, how we might deal with that. Because I know especially in the region we're working in we're right between the two Alka comes in, mostly Alka one I guess we get a little bit about the five to I guess right Dave. Anyway, I'm wondering how much overlap there is between the two sources and what we might look at besides going to higher resolution techniques to differentiate them. Yeah, that's a great point. Ryan, recently, I had some information I studied an artifact set from a place called Hake Nasa cave in northern Chile. And I was pretty sure there was an Alka obsidian artifact there. I didn't know about the Chiranya source then. And, and I, and, but I noticed that it was, it was close to Alka one and I thought, oh, I, we've got to, we've got to go to neutron activation analysis on this. And I think, yeah, that might, that might be necessary in some of these cases but I actually asked my class cock, you know, he's the Dean of these things about how to do it, you know exactly your question. And he said that he couldn't figure out at the moment how to do it, except by using neutron activation. So, you know, what he suggested was that, you know, if there are these instances of ambiguities that a once you just take the time and effort to get it run by neutron activation. Of course, knowing Peru's export laws. It sounds easier to him than it does to someone like you or me, or Kurt, but, but that may be necessary. Who knows, maybe if, you know, if broker keeps improving the quality of this machine and it'll eventually allow us to get at the elements that the neutron activation is, is using now. But I can send you his response on that I have it in the email. So those six samples Richard that you analyze that you assigned to Toronto from Omo are via neutron activation. Yes, they're all via new track. And they were from Paul Goldstein's excavations. But you know, one of the interesting things is the difference between Omo and, you know, a serial vowel, you know, it says stark, you know, they're so close and yet it's a different. It shows the power of the state. Yeah, it does really. I mean we have hundreds and hundreds of city and artifacts and I think, well, Dave can speak more broadly that she's been working with Paul on analyzing everything else and T when Aku and the valley from XRF perspectives. But the difference in quantity is vast and the difference in the type of material. I was talking about Omo, I wanted to ask Richard. Do you think that the presence of Chiranya at Omo was maybe because she by wasn't accessible at some time, perhaps because of worry. No, because, you know, the, the chivay is. It's so common at T when Aku is 77% of the obsidian. So I think it has to do with sort of the, the internal social dynamics of the to be cock a drainage that the people in Omo must have had some social ties to this sort of God forsaken area. And where Chiranya is located, you know, it's a very provincial very local and rather than going to T when Aku and acquiring it through that source, Omo was instead calling in these kinship or, you know, fictive kinship, or other kinds of ties or or or caravans from that area. Everywhere else seems to, you know, you look at, you know, we ran really a large sample from the rest of the TV cock a base and, and I have a big set also that I did with chip Spanish I haven't we haven't published it yet, in part because it's so boring it's all chivay. You know, but none of the none of it showed the Chiranya signature. So, really, the, the that that source is just staying in the southern TV cock a base and, and with the exception of going to T when Aku or to Omo. And that's probably for different reasons. The route from the coast is is pretty nice like up to Utah near Erika. That's a possible route to Omo as well. Right now there's no trouble in getting to Omo. It's kind of in the works with Paul right now but some of the PXRF data of some of the smaller debitage from Omo is also picking up a lot of the smaller sources. So, potentially even anio and other some alco sub sources. Yeah, so, well, let's hear more about that in the future. But yeah, I think there's a lot of interesting stuff happening in Motegua drawing in a lot of different variable sources. Did you say there's a neo at Omo? Yeah. I guess I got to hold that site. Yeah. This is our, this is the Indianist session here. Is there any other any of these questions. Well, the other thing about Sharanya or about Kamuku is that it's so close to Akunkawa but it must, that must be pretty lousy obsidian because it doesn't go anywhere and they don't even use it at Calcutani, right? Even the people who are sort of sitting on it would rather go and get Sharanya. But yeah, the other one we're closing in on is, you know, in that article with Karen and Sarah here we talk about this Choombi Vilkas type. We came, someone found a source in the Choombi Vilkas area that we thought must be it because it was in exactly the right spot. But when we ran it by neutron activation, there were small differences between the source samples and the artifacts and we re-ran the artifacts from that old 2000 article. So now because of the pandemic, they were unable to go back. But my class got things that probably the actual source that was quarried is probably very close to where those source samples have been taken and so hopefully we can get that one out of the way I'm trying to knock these rare types off. But if you're in Choombi Vilkas, go look for it. You mentioned the Makusani being really unusual in appearance, but it's, is it very good for toolmaking? My sense from Nathan's article was that it wasn't that great for mapping that was just aesthetically interesting. Exactly. I think it was mainly that it's cool looking. Yeah. I don't know how much the visual qualities of obsidian affected the choices in the central Andes. Other parts of the world, it was very, very important. In central Andes, you know, you don't, for example, in QCC, you have all that sort of blood red, that dark red obsidian and, you know, you'd think that would have stimulated some sort of special attention or, but it's just mixed in, you know, with the other stuff. Not like the particular obsidian in Mexico. We found one good point at QCC said that had a, the red was on the tip and the rest was black as if they had mapped it to look like it had blood on it. Really? That was pretty neat. You should publish that. A book cover. Yeah. So I got a follow up question for Kurt and Dave about, I'm sorry, I'm going to keep on the worry stuff just because that's my passion, right. So what do you guys, I mean, so Dave stuff is pretty interesting in that specialization of the certain subsources. Are you guys still thinking though that these are still that there's no real like, kind of, I don't want to call it industrialized but, you know, worry kind of exclusive access to certain sources or industrialized kind of extraction at certain sources, like alcohol one, or do you really don't see any evidence of that on the ground is such a broad and expansive source that they're not going to be able to really control access to it and so we're never going to be able to understand that kind of perspective on how worry is interfacing with those sources. That was Donna by the way hitting me for going on too long. Hi Donna. Hey Donna. Yeah, it's, it's interesting right Justin Justin Jennings went to the Kota Wasi Valley to look for evidence of control of the Alka source, and then didn't find it. But, but now we know the Alka source, you know the action really isn't in the Kota Wasi Valley. It's above it. So, so if the if the sources way up on the plateau, you know there are no towns up there that are big and there are no massive installations. And I don't know I'm just spitballing here but it seems that one of the if you wanted to control it you would need to control the transport of it, not control the outcrop itself. And, and so you'd look, you'd look for installations in the in surrounding valleys along routes that lead away from the source to other places that are useful to take it. And, and maybe Dave's, Dave's, you know, found some of those in one of the principal routes and we probably need to look at others but I'll stop there. So just from the, the worry. State Center in the mahes that was the focus of my dissertation. I think it's more direct procurement. It's so much Alka one. And whereas the surrounding kind of local settlements have very, you know, makes a different long distance and local sources. I'm not too sure about control. I mean it's just such an expansive area. But yeah I think it is that was focused on trade routes. You know, might factor into it but the same time the locals have, you know, a lot of, you know, a lot of different forms and varieties so I really don't see any control except for cannot direct procurement maybe by by worry and it's going up to the major bedrock sources. Yeah, I mean I gave some thought to this, you know, in relationship to key species source but it's the same is, is just you know when people talk, you know, long ago about these different states controlling obsidian sources. And I think in their mind they were thinking of something closer to the South African diamond mines or the, or the Inca gold mines, you know, where you have very specific spots that you can actually control but all the major sources in the area are huge, you know what you said 2000 square kilometers or I mean it's gigantic I don't see how anything I mean we can't control our own border right and it's it's nothing like that so I'm why they could do that in history but on on, you know, the Wari Road system has never really been fully studied and one can imagine that there are various points along a highway system whether it Inca or Wari whatever that you could close off movement and and prevent the sort of long distance transport of obsidian that has been, you know, been authorized by the by the state so I think the highway system is a place to look if we're interested in in state intervention in the movement of the of the volcanic last. Yeah that was exactly what Dave's dissertation tackled so at least for the. I look forward to reading it. So go read it. I look forward to seeing it. It's not done yet right. I think it's interesting to see that this is because in the case of the by the Cusco, like, no in the Cusco valley, you could see all the sides, the main importance, the middle horizon sides. They show up this Chi Chi by source, you know, so the Chi by sources very important for this middle horizon sites controlled by the wise. So how they get there in because because including in Piki Yachta or New York will be I the source of the obsidian is Chi by so like Richard said, and we will agree that it's important to find the road, the water road, you know, to go to the bio Cusco or the agreement valley will be the next one to look like an area where they were going through to Cusco, which road they were choosing, you know, if it was one principle road like it in case we have secondary roads. It will be nice. I really would like to see you. David read. Yeah. Yeah, I defended in December so I can email it to those interested. Is it a Chicago circle. You I see. Yes. We used to be Chicago circle. We don't go by that anymore but I'm not. Yeah, I always confuse this is Chicago circle. Yeah. We're showing our East Coast, do you know. I will go to just a city and exchange question middle horizon. Dumbarton Oaks is sponsoring a workshop next weekend. And Mary Glacky gave it a nice paper on the worry sites of Cusco and specifically talks about. I mean from rock G where Bill Siller has been working down through our and Piki Yachta and, and down on further than that, there is there's a very interesting corridor of worry movement. That, that, that might. Hmm. Your question and calm. It's very interesting. I was excavating three weeks and Piki Yachta as a volunteer. So I got very interesting on that. You know, it's a new offering that they have found. The one, the same as a Reola is a new offering is so beautiful. The same figurines. Going to be another one just like that. Yeah. Heather like I run some of the XRF for Heather like man and I were preparing. For me. Give it to you guys after me. After the pandemic. Yeah, there is very eager to finish that job. So one thing I wanted to mention is I've been analyzing some stuff for Axl Nielsen from Northwest Argentina. And they have really high of rubidium over, over 1000 and some or over 700 parts per million. So I had to borrow three samples of obsidian from my class cock to calibrate our broker for high rubidium. One of them is moot is not the sunny. So it's useful for calibrating, or you can use one of these missed samples, but, but it's something relevant to the, to the andy's only I think is, is that we have these super high rubidium values if you do any work further south you'll run into this issue. And the 40 sample set from her doesn't go high enough for the rubidium down there or my Chris on it for that matter. And Mike only has one piece of my Chris on it from Nathan Craig so anybody's in I have beauty and has a few days to kill. If you can get some more Chris on it. Nico I've got, I've got about 12 sitting in my office. Mike would like some, I'll send it to me might with glacial geologic work over there and, and we just found it. And I mean we knew, we knew from Nathan Craig's work that it was over there but so that's why we knew what it was, but we never we've never done anything with it. Well, yeah, it's good for that upper end of rubidium then for, you know, raising the range of your calibrated results. Cool. We've actually found some artifacts of it too but really, it's almost cast to it. Sort of greenish clear. Yeah, I'll send them to I'll send them to him. Perfect. You know, Nico and also I'd like to also just throw in a pitch if people are looking for permanent repositories of raw material. The Field Museum has started a raw material collection of volcanics and in fact it's a big geoarcheological kind of a geoarcheological materials collection. And so, we're willing for long term to take on curation and then loaning that out to anybody who needs it. So, I know that people have a lot of collections that are wondering what they might do with their permanent raw material collections. So will the University of Chicago be there for a long time. We hope so. It's actually a field it's a field museum so we're actually an independent institution. That's better. That's better. Well, I can I just have a paper coming out in geoarcheology on the Rio Grande second you put secondary deposit study and, and, you know, I talked about, I don't know if you're on Ryan but the East scholarship.org that we have at University of California. And that one of the reviewers, it was anonymous I don't know who it was was saying well I don't know if that's very permanent you know you should keep it with Wiley publishers and I go, why did what somebody might buy Wiley publishers tomorrow and it could disappear you know I think the University of California probably be there for a little bit longer. That is one argument I didn't want. So we still have to launch our, our labs official webpage that will make public all of the results performed through the field museums elemental analysis facility, but all the data is being archived on the museum's enterprise database system, which also houses all the information for the museum's objects. Yeah, good idea to lose that. And so that means they can't afford to lose the data from the. That's great. I mean one thing I was when I was working with Steve on these reports we were trying to get the results, the part per million in a table format, so that, you know it's like a CSV file attached to the PDF. So you don't have to try to even have to retype it. I didn't do that. Yeah, I didn't do that through 2016 but I'm working on all of all of them through now, and I'll have a separate and attached CSV file to that. Yeah, that's a lot better. So I still need to talk to you about doing batch uploads. Okay. Well as long as the University of California keeps my pension coming. In New Mexico than the area. You can't believe it. Yeah, yeah. You're one of the many reasons I'm here. Well, Mike, harking back to your call about kind of centralizing some of the data and it might be interesting to think about how these different enterprise systems that are holding data can be linked together and be perhaps drawn up on I mean I know from this kind of work we are, we're on an enterprise database system that we can link to the other museums like the American Museum and so theoretically you could set up a web server that would dive into that database and pull out whatever you wanted from it, and if it could dive into multiple databases, you would actually allow people to maintain their independent databases for archiving their data, but have a central authority or a central portal for going on and searching and getting that's kind of an interesting perspective on how obsidian data could be archived and served kind of in a decentralized manner. It should be easy to do I would imagine. I've seen that with cartographic data where they're they're basically sharing the metadata, like the bounding box of a scanned historic map, the map itself might be in the, you know, like in the collections at the Harvard library and you may or may not have access, but the metadata is there so you know the map exists and then you go through various channels to try to get it and could be a similar thing with museums where just know what's there and then the data is another story. Yeah, I mean I'd like to like to finger the US government to do that but you know that we could get the next president could be Trump and just throw it all away so I don't know if that would be a good idea either so I don't know where the the depository should be. And maybe in a way it's better to have a private museum like the Field Museum do it or something like that. I don't really know what the solution is. I think Craig Skinner would be. I mean he's technically retired now but he's not on right now but he could have some pretty good ideas I don't know if anybody's ever used. Well supposedly he's going to put it online. He and I 99% him have a North American obsidian database through file maker. And it is incredible I mean it's when I when I have one of those weird ones I'm in the Southwest and I have something from the Utah or Nevada or even the Northwest. I can always find it with that and it works. That's really great. You know out there online but and I imagine he will at some point but he's like five years older than me so we got to push him to do it before he dies. So that's that's that's we keep saying we got to do it before we die man. I'm not dealing with Craig's data if he if he dies and sends it to me. I've got my hands full full with Berkeley so. Oh yeah I mean math students that kind of same thing on a much, you know, a micro level in a way. I mean it's not, but it's going to be great when it's done and, and of course Richard, essentially. I don't, I don't know the data that Richard was comparing to Berkeley I guess you have that that data yourself it wasn't from man. There was a data that was, I think salvage from from Frank is ours. Oh yeah, records yeah. I mean, but it's so hard to you know to to think back to those times because none of us had computers. Yeah, right and I mean even making a Xerox was like a big deal. You had to argue with the department. Yeah. And then the things that came out of the LBL lab were so large you couldn't copy them because they were the wrong size. I think yeah. Well that's another thing. Going back to Ryan is that the formats we're using now, we can do it. It's great it's all cross platform anything but what about in 100 years I mean what was it going to be like I guess, I guess you can't worry about it you just have to do it and. Yeah, hope that somebody can translate it in the future. Yeah, that's what. So the Lawrence Berkeley lab had a, I'm trying to find a photograph on on my computer, but it was a CDC 7600 mainframe. And I saw that thing yeah. Yeah I had magnetics and magnetic mass storage in capsules that are big. Yeah. Right. And then they had punch cards by the time by the time. Yeah, so the data were stored the NEA and XRF data were stored on the magnetic storage, and the contextual and descriptive data were stored in punch cards. I wanted to do a print out of both. You had to get the right magnet the Mac right mass storage and feed in the punch cards and then the correct codes, you know to execute everything. Fine, except it was never updated so by the time when they closed the reactor in 88 or 89. They didn't have on site, the ability to read those mass storage things or the punch cards. So Frank and Helen had to go find a company that could do. And they did and that was great. And they that company gave them a stack of three and a half inch floppy disks, and said here you go here's here's two sets of all these data. One set of those floppy disks went to to Hebrew University. And one set in a burger. Yeah, we're Perlman and, and, and Joe Yellen and young gun of it worked. The set that was stored at Berkeley when Mike went out in 2006, when Frank was cleaning everything out. Yeah. He took those disks and he took the first one he popped it in the computer and it was unreadable. It had been, you know, 1991 1999 and one that happened by 2006 my guess is the magnetic film had degraded to the point where it was unreadable. So they spent all that time and effort to get them all off the mass storage and the punch cards. And it was still unreadable. By the time Frank finally cleaned everything out. And so I say digital and paper. And they've been given to the Hebrew Union college to do so he so that's a funny story. The Senate Hebrew at Hebrew University was given to young gun of egg who who was the archaeologist part of the archaeometry laboratory so when when is moved there in 7374 he was working with Joe Yellen who's a physicist and Joe hired yawn or the lab hired yawn. And there was there's a schism that's there. You know, one person says the other ones, you know, real SOB and the other one says the other ones the real SOB. So there's some sort of personal issue that's there and yawn never gave those discs, as far as I'm aware to anybody else. Okay. So. Um, but I have a whole paper case box of 11 by 15 inch dot dot matrix fan pulled computer paper from Berkeley if anybody's looking to, to house it. Yeah, I learned SPSS on punch cards. And, but you know that's a piece of software that's been updated constantly so right. That's, that's, I didn't, that's not an issue. Even even Microsoft Excel. If you have an old like a Microsoft Excel one or two it's it's difficult to get that in. Right. I had that I had that problem I had to go through. My Quantex computer as an XP, and I had to go through that come back around. Yeah. And I've got. So when I left Mer, I just copied my entire hard drive to my external hard drive. And there's stuff on there that's, you know, Lotus 123. Oh yeah or WB on files. Yeah, I just yeah. So digital is great, but you have to update the files and and if you're going to do digital CSV I think is probably the best way to go. Yeah. We hope it's no paper. So. Yeah, I mean, Nico was yelling at me for not doing CSV files on 1985 through 26. I just ignored him. So that the bet you can still get the table which was an Excel table out of word. And then do it yourself but yeah yeah I had an undergraduate we like reverse engineer your PDF backwards into Excel and then we could save out CSV. Right. Yeah, that's what I've been doing too. So everything, assuming that the batch file system is going to work. I'll attach a CSV to every one of them. So, and that's quite a bit I mean that's 2017 through 21 now so. Yeah no they're permanent URL so those, those will be available, you know that location. I have, I don't want to waste time on this too much but now what about the search utility on the title site number, my name, you know and that kind of thing how does that work. Well you scholarship has good discoverability. It comes up in Google scholar and things like that you can test it with the title in quotes. One thing I was going to mention is, so I've been using open context, which is kind of like TDR it's a, they're both recognized by the NSF for for archiving your digital data and one difference though is that TDR requires a login and open context doesn't so you know with like to like Ryan your museum system. If you don't require a login it's much better for like the, you know, other, other analysis systems can just use, you know, use the URL or the uri grab the data and kind of integrate it without some login headaches. Unfortunately, we actually serve. We serve our data up to an internet database so there's a set it's like a second copy that's publicly available. Actually, it's not a very pretty interface yet right now. But but that's what this so this this database is a login database but it allows you to identify. And this is the same thing that serves our online catalog at collections and collections at field museum.org. It serves it up to an internet database and that's publicly available but there's still behind that a protected login database and only the fields that you choose to make public or made public in that fashion, and they're changeable on the fly. So, yeah, like site location for example would be hidden. Yeah, exactly. Or if you have some sensitive information that gets up there we can actually pull it off because we have a cultural identifier cultural descent group said that's sensitive information shouldn't be up there. We can turn it off immediately. That's a great idea that kind of tangential to that on that geo archaeology paper I was just talking about. The editors are European, and they wanted me to put the site location information, but this is for the Americans here. This was on Bureau of Land Management or Bureau of rec land and I couldn't do that. So that was, you know, it's kind of an interesting thing. If you had this two levels of availability like your clients talking about that would solve that issue. Yeah, so while we're talking about the Andes I wanted to mention I was communicating with Kurt about the idea that alco was glaciated or not. During the there was that theory, but it sounds like you've wrote about this you published on this right in 2015 or so. So, latest is that it wasn't glaciated in the in the late place to seem. It must have been a pretty cold. If you're getting quenching must have been pretty cold. Yeah, yeah, I forgot to mention that I, one of those things I forgot but yeah the it's been, I mean the source has been glaciated for sure, but just thing that, but just nothing that has is relevant on human time scales. Yeah, right. So the last really extensive glaciation up there was the penultimate glaciation over 100,000 years ago. The last glacial maximum glaciers weren't even very extensive in the Andes. So, right. So, yeah it's just not an issue for human settlement or resource use or anything but maybe at the highest elevation sources like Chiwai and that one I showed that was over 5000 meters, maybe those would be covered by snow, or, or ice, but still it would be very cold. So, you know, that's what I just can't I just can't imagine the yellowstone sources coming up to the continental glacier. Can you imagine two kilometer thick that you wouldn't want to be anywhere within 1000 kilometers of that place, you know, man, just amazing to think about. Yeah, wouldn't that make like a giant vapor explosion. Oh yeah. Yeah, yeah. It would be almost free out of magmatic is what you call it with trilogy would be just crazy. However, there, there was no muscle, there couldn't have been any intermixing because you have to stay below about one weight percent water, or you're not going to get a glass you're going to get a bit for fear. So, yeah I don't know nobody's seen this that's the thing I mean it's such a rare event. There's nobody alive has ever seen obsidian produce. I tell you, if I'm 90 years old and there's one happening somewhere around the world I'm going to get there somehow. You just got to go over there to Ireland. God, I can't believe this. I said this to all of my Irish colleagues they really love this. So, one of them is out there now looking for all the volcanic. Okay, could you take, could you take one of those DC 130 fire fighting planes that you guys have out west. Oh yeah. Yeah, buy over Iceland right now and just drop water on it. Yeah, why not. Well I said be better. Yeah, yeah. I just want to see what happens. Yeah, just. When you when you create a vapor that rapidly now I'm going way back to college chemistry. I mean all kinds of weird shit must be happening that's just amazing to think about. That's what it says in the college chemistry books all kinds of the weird shit. At least mine. That's all my notes. Yeah, that's great about bringing retired you know I, when I was teaching virtually I couldn't say those things but yeah you did. But not generally in the classroom. Oh, so, so fx is here I see him. He's muted. So, do you swear in the classroom in French. Exactly. They don't let you say that. It's necessary to speak with my students. Yeah, right. Or maybe, maybe graduate seminars or something. Yeah Carol is not here she can attest to it. My connection is on here. Oh you are here. I hear you talking about squaring in the classroom. They can't fire me now. Did that when you were at Berkeley right now. Generally, you kept it to the grad seminar so. Yeah. Yeah, because I had a lot of stuff to hold over on like getting the hell out so. You need my signature. Yeah, it's true. I mentioned the Phillips wavelength machine, they've completely remodeled that whole floor of geology of DPS. And I mean I had a hard time finding all the parts to the context, they moved it around. They're really tired. Yeah, see they don't care. I mean, geologists are not interested in X or F anymore. Generally, while mining engineers I use it, you know, use px or I don't really care. Archaeologists and scrap metal yards. Yeah, yeah, that's right. Yeah, an interesting combination. And toxic, you know, substances to like museum arsenic. Yeah, yeah. Right. Yeah, so you don't, you don't know if they scrapped it completely do you. I couldn't get to that part of the building that Tim would know. Yeah, Tim. The thing is, the infrastructure to support an instrument like that is very expensive because you have to have chilled water constantly. That's how they cool the detectors and, you know, it's multiple detectors to so it's a great machine when it's working. I mean, Carolyn did most of her stuff with that. When it ain't working, boy. Well, there's wasn't the one that started running backwards for why. Yeah, right. Right. Yeah, because it has a, our arm that comes and picks up the sample, and then puts it in the chamber and the chamber is closed up and analyze it. One of the problems for archaeology of course is that the, the sample cups were about this big. There's a lot of large samples you can't do that. And of course, you always no care, you know, they're just going to chop it up and is whatever size pieces they need to and throw to the machine. So, so it was a great idea for a while. It saved Carolyn because a spec trace for 40 died. Before you got the thermo Fisher context. Yeah. Well, the first one where the spec trace, the ones that had that copper to that took Tim and I must have been a month before we could find where the rhodium peak was we just had to do. You just said experiment. Well is it here and then run something. Well, that's not it. Is it here, because if you're ratioing to nothing, you're going to get nothing. So it took a while. Once we got it, it was fine. And it was really good for metals. Yeah, because that's what I bought it from Intel, and they were analyzing their hard disk back when they were still making hard disk. And yeah, when broker comes to the Bay, they're usually down in the South Bay down at the Silicon Valley clients. Yeah, well thermos down there too. They used to be, you know, now that Wayne retired and I haven't had much contact with them anymore. I think they're assessing the materials coming from, you know, the Chinese factories for Apple and others. Is that right? Yeah. Yeah, I mean they were they had a workshop in, is it Apple? I can't remember. Are you talking about broker or thermal? This was broker when they were going to do a tracer 5i demo. Oh yeah. Down there they were evaluating the alloys and the iPhone case or something like that. Yeah, it's too bad that Wayne retired boy. I really picked his brain a lot. I have some great oxide methods that I use because of him. He's still interested. Yeah, he'll answer emails and things like that. Yeah, I got his non non thermo Fisher email address. I think I do too but if you think about it send it to me. Okay. I can get him over here because he loves New Mexican food. So he brought his bronze calibration set up and we, yeah. And then we were setting the charm set from my daddy. Yeah, I got, I got both of those. What speakman was still working. I got the charm from him. And of course the one from Wayne. So, you know, I've been analyzing the, the membranes copper bells. And it's really handy. Yeah. I don't, what's really interesting about that, because you would know about it is that, you know, the whole idea has been well these are all produced in Mesoamerica, and the bells are, but, you know, membranes is right near that huge copper mine near Silver City. And they were taking raw copper and producing these little effigies like bears and things like that. And that's local. Pretty neat that the guy I've been working with is the forest archaeologist for Hila, Hila National Forest, well he had a heart attack and so I don't, you know, I haven't heard from him. So we were ready to write that up. But, but it was because of that those standard those sets that I was able to set up a really good metals. With about, about four conditions for each one of those methods. Yeah. Yeah, so it works pretty well. Well, we had the bronze, we had the charm set going on the Thermo Fisher and the Brucker Five Eye. And our Brucker, the detector quit. Luckily it was still under warranty, but it seems like there's still some, you know, reliability issues with the tracers. Yeah, if you remind me, I'll send you my method. You'll have to use the standards that you had, but in other words, take my method. And if the standards are the same, just use those. And if there's any that you don't have just toss them out of the metal. To the quantics. Yeah, that'll work. Yeah, because it was hard to borrow the charm set. Yeah, I just, I was just lucky that Speakman had it at the time and he sent it to me. So I added it to the set that Wayne had given me. And I also have used some of the US Mint coins because they, they published their composition and throw that in too. You know, like the, the, the dollars, the dollars. The problem is that they use like three compounds to make those things, you know, there's not very much. It was very little and it's pretty pure. It's pretty good stuff. I learned that because I had the method and then analyze the coins. And it came out almost right on. But what the men's publishing. That's another thing you could throw in. Yeah. There was a one of Kim Shelton students who's looking at bronze swords from. Again, it's pretty cool stuff. Yeah, yeah, she sent me a couple of emails about that. And there's a helmet in the Hearst Museum. That's all battered. Looks like somebody had probably had a very bad day in that helmet because it was a big dent in the side, but he was, he was XRFing the different parts of the helmet, the rivets and the different component trying to see if the metallurgy changes. What time period is it at Bronze Age or something? I can't remember. I see me probably. Yeah, that'd be cool. Late Bronze Age. Yeah, that's a really good application for PXRF. Well, the museum's still completely locked closed. As far as I know, I can't get in there. Oh, is that right? Analyze a little obsidian. Yeah. They won't let anyone in. They still have that facility down off. Was it off Sam Pedro? They moved it to the Richmond Field Station. They got an old Sam's Club. It's a huge building. But it seems to me they let you in there. You know, I don't know where the collection is that you're interested in is there. Because they had a lot of stuff from Chihuahua. That brand and those guys that collected. They have a database completely online now too. Was that right? Yeah, it's called collection space. I'll put, I'll put the link in the chat if people are interested. So they put the target catalog on it? Yeah, finally. It took decades right to digitize all that stuff. Yeah. Well, it's not tiny. You know, right. It's called portal. Portal. Let's see. It's useful. There's a lot of Latin American stuff in there. Yeah, there is. Right. Right. You know, you know, I can't, you can't access my book anymore. I don't even know if they threw them all out or. Because I had a couple of people ask her copies and I don't have any copies anymore. Who's the director? Oh, she's from. She's from history of art. She's from history of art. Oh, she's from. She's from history of art. Oh, really? Lauren. Yeah, it's no longer Ben Porter. Oh, I think, I think Kathy knows, knows her. Yeah, Lauren. Cause she keeps in contact with those guys. Yeah. Yeah, they're still in the midst. A lot of NAG for stuff going on still. I pasted the link in there. You can see. Yeah. Object type. Yeah, I'm looking at it now. It's pretty nice. Oh, there's the issue collection too. Yeah. What I'd like to see is more sort of tracking of research results. Yeah. Like when you borrow stuff or when you visit and analyze stuff, they need to really make sure that. Those results get put into this database or at least somehow available to subsequent scholars. Yeah, that's a good idea. We used to of course require that. They submit whatever. Publication results from that. God, I left him. When was that like 20 2004, 2003 something. Yeah, I was hoping Craig would come back and. We could talk about, you know, an international database. I don't know where he is. There was that. I don't know if Matt's here. There he is. There's Craig. Yeah, there's a, there's a Google Earth file with all the obsidian sources around the world, right? I think Matt was involved with that at Mer. Right. Yeah. I mean, we have parts of that. You know, Craig's got the incredible North American thing, but there's no data attached to it. So that would really, you know, just. You know, Craig, before he dies, could just put, put, take the data from his database and then meld it with, you know, the iOS thing. God, that would be incredible. We keep talking about what we need to do before we die. Hey, you're muted. Yeah. He's muted purpose because he's. Got it. Yeah, you got it now. Okay, I'm back. Yeah. Talking about, you know, the international database stuff and, oh yeah, we got all these data. And, you know, if you can take the iOS front end, you have and take your database and put them together. And you're, you're computer nerdy enough to do that. I know you are. So that would be really helpful to at least one person here. Me. No, Nico, you're pretty good too. Yeah, yeah. Well, one, I mean, those results are from calibrated instruments. Yeah, they all are. Yeah. Yeah. Yeah, it's all essentially from, they're all daughters of the original Berkeley stuff. It just goes all the procedures. Yeah, same software. Great. Yeah, that'd be terrific. Yeah, because my, you know, mine is kind of a second generation thing from Berkeley. They came through Tom Jackson and. Right. Kathy Davis. Yeah. Yeah. And then Chris Stevens is connected to this too, because I sold him one of the spectrase connexes. I remember that. It lasted about two weeks, I think. But I had my money. So just a little guilty about that, Steve. No, I guess not. Well, that machine, we were talking about that earlier. I was a pain in the ass because it had a copper too. Oh, I remember that too. It took forever to find the rhodium. I wouldn't know what to do with that. Oh, it's just, well, it was just experimentation. Yeah. So you'd analyze a sample ratioing at this, you know, peak background peak, you know, a background peak background. Right. No, that's not it. So you moved to the next one, then you moved to move. It took us a month. All right, gentlemen, I'm going to interrupt you and. And introduce our post lunch. First post lunch speaker and paper. Thank you, everybody. Enjoy their, their quick break. All right, we'll, we'll disappear. Reminder that the breakout rooms are available all day. If you do want to have a private meeting with somebody. You can have it here in the, in the general meeting too, which is great. But there are private meeting places if you, if you so choose to, to, to discuss things in there. So our first speaker is. He's going to be presenting a PXRF obsidian analysis of two sites in Southern, in the Southern basin of Mexico from early to late post classic by Guillermo Costa Choa and Bernice Jimenez Gonzalez. All right. Thank you very much for Nico and Lucas. So let's start. Can you see my power point? Yeah. Yeah, I can see it. Obsidian has been used in central Mexico. It has been used as the main raw material for chip stone tools. At least since 4,000 years before Camonera. It's economic and strategic importance. Has generated models of the possible control of the production of three large city states in the basin of Mexico. You can do that. And then most people. Without a consensus on the ideal model until now. For example, In the south of the basin. We have a second day of the city's production of the total of 30 wakan spends and something. Proposed a city based workshop industry involving substantial export production on the state control. On the other hand. Charton posits a high volume state control obsidian industry with the bulk of its workshops situated outside 30 Wakan. long-distance trade in status items between elites. In the case of epi-classic and post-classic models, the obsidian procurement and exchange system has not been less complicated to be theoretically modeled. First, due to the few studies on lithic production areas or because of the scarce stratigraphic control of the collections or even because of a poor assignment of the source of obsidian, particularly in the case of gray-black obsidian visual analysis. The main objective of this study is to evaluate the changes in obsidian procurement from two sites with restricted occupations, exclusively from the early post-classic in the Akatla-Tulliwalgo site and late post-classic to early colonial in Paxo-Chimilcosite. This with the aim to evaluate the differences in obsidian production and exchange system before the rule of the triple alliance and the development of the Aztec state. For this, a PXRF analysis of 100% of the lithic assemblages from both sites was carried out, analyzing the technological characteristics of the lithics and comparing the results with model proposed for sites such as Tulliwalgo and Suchicalco. A total of little more than 800% artifacts were analyzed in compositional and technological ways. Post-classic in southern basin of Mexico from Tula to Tenochtitlan. The post-classic period of southern basin of Mexico has been divided into early post-classic 900 to 1150 AD, middle post-classic 1150 to 1350 AD, and late post-classic 1350 to 1531 AD. The early post-classic is characterized in the Suchimilco area by materials of the Aztec one ceramics, mainly black and orange, on its Chalco and Miskic types, Masapa figurines, and Toltec chain types such as Plombate, Alicia Callado, St. Barnards, and Abracafe Burdo Bracers, in addition to the predominance of gray or black obsidian over the green obsidian. During this period, there is a significant increase in the occupation of the lecture plane, related to a demographic increase in comparison with the previous epi-classic period. The late post-classic marks a break in several senses, in lacrosse and communities of southern basin of Mexico. This change seems to be highly influenced by the conquest and domination of the area by the triple alliance headed by Tenochtitlan. This period, characterized by Aztec III and Aztec IV water types, marks a period of accelerated demographic increase linked to the expansion of the Chinampa system and the construction of large waterworks that radically transformed the Lacostrian landscape. For this period, an absolute dominance of green obsidian and prismatic bay technology is observed in the litic assemblages of these Chinampa domestic units. The study sites, Acatla Tugiaualpa. The Acatla site was located in the Sochimico-Lacostrian lakebed. It had an approximate area of 11.5 hectares where several large platforms were located, with houses of one to three rooms. According to the classification of Parsons, this site corresponds to a large nut-lated bilage, with an occupation between 900 and 1200 AD. The houses had rectangular floors with rock and nadobe foundations. Some of the houses had the remains of fireplaces inside, with an area for funeral alboreas. In other open spaces, activities such as the manufacture of praetal points, textile work, and food preparation were carried out. Despite being a minor bilage, long-distance trade gods were recovered, such as grid stones, plum bait, and fine orange powdering, copper and shells from the Pacific and Caribbean Sea. The Paxochimico site is a cluster of Chinampa agriculture domestic units of 700 hectares, excavated by the Proyecto Salvamento Arqueológico Sochimilco, or Pax, a salvage archaeology project in the area currently occupied by the Sochimilco Ecological Park. The residential units were built on agricultural Chinampas that were expanded to generate housing platforms. Three of the carbon dates have recently been obtained from the largest site, San Gregore Tlapulco, indicating the beginning of the occupation toward the early 15th century and an abandon due to the cocolistic epidemic at the end of the 16th century. The late post-classical residential units were made up of rectangular dwellings, some with internals of divisions, separate by open areas where one or more hearts were located. Its walls were built with volcanic stone and guadalanda. The characteristic ceramics of this period correspond to the Tenochtitlán black and orange world, while the figurines represent classical deities of the Aztepantheon and the lithic group is less varied than the early post-classic, with little presence of projectile points. The PxRF obsidian source analysis. For this study, 10 of the most representative chemical elements in the samples, manganisium, iron, zinc, gallium, thorium, rubidium, strontium, yttrium, zirconium, and niobium, were evaluated using the AxRF Bruker handheld device, according to the methodology established by Jeff Spickman. This configuration coincided with the matrix-specific factory-installed obsidian calibration. Alamos obtained comparable results with other reliable methods such as neutron activation analysis. Obsidian samples were recovered from comparative analysis from 23 sources in the Mexican volcanic belt and the Guatemala highlands. A comparative statistical analysis of the archaeological and geological samples was carried out through principal component analysis, hierarchical cluster analysis, and by plots of strontium and zirconium. The results indicate a dominance of green-black obsidian from the tumba and ocarreo over the green obsidian from Bachuca, Sierra de las Navajas, during the early post-classic. In contrast, Bachuca green obsidian dominates the late post-classic obsidian assemblage, while a tumba obsidian is restricted to a lower percentage in bifasciants. Obsidian from ocarreo was identified only in Angelical Bed, a provable relic. The obsidian assemblages and their provenance, early post-classic versus late post-classic. In the early post-classic, projectile points were deactivated with the highest frequency at the Catalan side, representing since 61.3 percent of the total collection. Most were made of gray-black obsidian from ocarreo on a tumba. The Texcoco projectile type is the most common. The points were manufactured mainly on flakes and to a lesser extent on prismatic blades. Bifascial represents 1.23 percent of the sample. These are massive artifacts, almost all fractured due to the dimensions. They could have another function, probably bifascial knives. Due to the lack of use-wear analysis, our classification is based only on artifacts morphology. A class of artifacts made on macro blades are the end scrappers, which represents 4.43 percent of the sample. Most of them have a morphology typical for magei processing. Prismatic blades, on the other hand, represent only 8.4 percent of the collection, a small percentage than the late post-classic. 38 percent of the blades comes from ocarreo, 32 percent from pachuca and o tumba, and o tumba represents only 1 percent. The blades are generally small. During this period, blades were used as half artifacts, or even to manufacture other tools, such as projectile points and eccentric. Only two cores were found at the site. One of them comes from ocarreo, and the other comes from Sierra de las Navajas. Both cores are very small in dimensions and have a polished platform, like most of prismatic blades. In one of the cores, it was possible to refit a pair of blades to one core, which suggests that, at least occasionally, small size cores with a polished platform were acquired by the inhabitants of Katla to extract small blades. This is consistent with observations made by Dan Hila Fortula, who suggests that polished platform technology was alternative for less specialized producers. Alluminal artisans took this skill to continue to extract lismatic blades in small cores. Late post-classic. Unlike the early post-classic, projectile points of Paxo Chimilco site represent only 3.5 percent of the assemblage. 48 percent of the projectile points were made with obsidian from Pachuca, and the other half with gray obsidian from Otumba. The typological differences between the artifacts from both sites are evident. Those from Pachuca being slightly smaller and with lateral notches, while Otumba projectile points tend to be larger, heavy, and irregular. No one of the artifacts are observed in the manufacturing process, so we consider that these may have already arrived manufactured to the site. Artifacts on flake or blade. The flake artifacts represent 8 percent of the sample. Blade artifacts represent 13.8 percent of the total collection. These materials were manufactured on macro blades and first serious prismatic blades. Prismatic blades, on the other hand, were the most numerous obsidian artifacts in the late post-classic collection, representing 76 percent of the total. They are slightly larger in dimensions than those observed at the Akatla site and are almost entirely manufactured on green obsidian from Pachuca. These blades are usually used directly, with minimal retouch of the edges and with lateral notches, probably for halving the blades. Nine cores were identified. Except for three, the rest have longitudinal fracture, apparently made to obtain a better grip and initiate abrasion of the core in order to make lapidary objects. Some of the cores show traces for the manufacture of lapidary objects as in the previous period. There are no large-scale cores and no evidence of blade production. Statistical analysis indicates that also the weights and measurement of late post-classic prismatic blades are more diverse. The average of early and late post-classic prismatic blades are similar. Results of the analysis and economic implications. During the early post-classic, Akatla probably was part of the extensive exchange networks of Tula and Cholula. Otumba is the best-represented deposit for this period in terms of total artifacts, but Ukareo is the dominant deposit in the manufacture of blades. This same condition is observed in other places such as the early period of Tula and Sochi Calhoun. Akatla seems to have been part of this trade network for Ukareo obsidian that dominated before 1080, in a period when the Otumba city-state was able to control the production of the homonymous source, while the green obsidian from Bachuca was not so relevant to the southern basin of Mexico. Smaller quantity of obsidians from Puebla and Saragosa, such as Saragosa and Paredón, indicates that Akatla also accessed the exchange spheres of other important centers such as Cholula, or even Cantona in its final period of occupation. In the case of the late post-classic, an abrupt change is observed in the obsidian sources, replacing the obsidian of Otumba and Ukareo with Pachuca green obsidian, as well as a significant reduction in the total number of identified sources. The practical absence of obsidian from Ukareo is undoubtedly due to the rise of the Taraskan empire and the beginning of hostilities with the Triple Alliance. The exploitation of the deposits of the Sierra de las Navajas, Pachuca, intensified in this period, probably as a response of the Mexica empire in ensuring the supply of a strategic raw material for welfare and economy. The absence of obsidian in the tax registration in Codex Mendoza shall have directly ensured its supply by displacing communities for intensive exploitation but leaving the bulk of the production to be incorporated into the market system. Also, the size of prismatic blades increases slightly during the late post-classic. The average for prismatic blade is still smaller and the scanned presence of cores or napping debris indicates that obsidian artifacts including prismatic blades and projectile points reach the domestic unit finish. So the Aztec market system and the figure of the 18th artisans should be seriously considered as the basis of the procurement of obsidian for the post-classic period in general. Thank you very much. Thank you Guillermo. We have a few minutes for questions. Yeah, I have a question for Guillermo. So let's get this right. In the late classic, there were standpoints produced from Otumba and then it looked like side-notch points from Ucareo or at least another source. What did you say you thought was occurring? Was that cultural or were there two different groups producing that? What do you think was going on? Well, Ucareo is almost double in distance from Otumba, Pachuca, excuse me, Pachuca source and three times the distance from Otumba sites. So we are thinking that this is a cultural trend, but it implies maybe general market systems. We don't know yet if it's controlled by Tula or another big site. I think it's not like so. Maybe just itinerant producers and independent market systems. Maybe the Pachuca system that we see in the post-classic is now yet in use since maybe the epi-classic period. In the post-classic, it's clearly that the control of the production and principally the control of the exchange system is not controlled by a local center such as Tula. That kind of goes back to a question that Rob Tycott asked me in the Southwest, differential access to obsidian sources. I was thinking about Joshua, who's actually on here now. We did that work and everything was produced from Otumba. Yeah, but we got to think that Otumba is not a good obsidian to pressure blades. And Puccareo and Pachuca are the best for that. I agree. Yeah, I agree. I like producing, if I could get it up, Pachuca. I like producing by-faced projectile points. Yeah, you can do almost anything with Pachuca. You can do anything with Pachuca, right? That's great stuff. All right, thanks again Guillermo. Thank you very much. Yeah, thank you. Our next paper is titled Market Places and Market Exchange of Obsidian during the 8th to 10th centuries at El Zotz Guatemala by Joshua Cuoca, Anna Bishop, Thomas Garrison, Hector Neff, and Stephen Halston. All right, well, thank you very much. Hello, everyone. It's a pleasure to be here. I've been, I've had my camera off, but I've been lurking in the background, grading papers while I listen to you, so I've enjoyed it very much. Let's see, your screen. Okay, how's that looking? Okay. Looks good. Looks good. Okay. So in full disclosure, my 20 years of giving papers, this is the first time I'm not going to read one. It could go horribly. It might go great, but I promise you it will not go over time. That's for sure. Right. So thank you for the introduction, Lucas. And as the slide shows, there's quite a few cooks in the kitchen on this project. And it's really folks who've been doing lots of different things at El Zotz. And this is an attempt to start to draw all that together. Obviously, it's lithics-based, but to sort of not just do a basic lithics paper, but essentially tie that into broader issues that are going on at El Zotz during the eight through 10th centuries. I don't have a lot of definitive results on that end, but I'm going to walk you through what our lithic analyses and the PXRF analysis have turned up and threw out some thoughts at the end. And then I'd love to hear what you guys have to say. So without further ado. Okay. So I did lie. The one part I am going to read is the introduction to the site here, El Zotz. So you're looking at a map of the Buena Vista Valley. And by the way, I put a little key here for you, as I'll be using these terms frequently. So if you're unfamiliar, maybe take screenshot. But the Buena Vista Valley is the northernmost east-west corridor that crosses the central myelolins. Both the valley floor and associated hills are home to numerous archaeological sites, most notably the classic period kingdom of El Zotz. During the classic period, El Zotz was ruled by the Pachan dynasty, which established itself by constructing a fortified hilltop palace during the fourth century AD. Later, it shifted the royal court to the valley floor for the second half of the early classic. After AD 378 and the Entrada, the Pachan lords were subordinate to the Teotihuacan back dynasty at Tikal and enjoyed a period of relative peace. When Tikal was conquered in AD 562, El Zotz allied itself with the invading snake kingdom and became particularly close with the lords of El Peru Huaca. So it's out here. El Zotz and Tikal over here. However, this became a time of dynastic turmoil at El Zotz, whose principal patron was no longer situated so close. Scattered epigraphic data from looted late classic pots indicate numerous rulers, including a possible prince from El Peru Huaca, who sat on the Pachan throne in the seventh century AD. During these troubled times, a local lineage settled at the intersection of the Buena Vista Scarpment and a north south drainage that bisects it. And that settlement is called the La Luna group. And you're going to learn more about that momentarily. And it's called the La Luna group because in the Lidar data, it was all pockmarked from extensive looting. So now that you have a little bit of a background of sort of the foundation early history of El Zotz, the data that I'll be sharing with you moving forward is all from the sort of final phase of El Zotz history, specifically the late classic and term of classic periods. So one of the things that I was very interested in at El Zotz was in 2015, I did very basic lithic analysis sort of as a hired gun went down and looked at stuff they had in the lab. And just simply plotting the distribution of obsidian at the site was very revealing in that some of the highest concentrations of obsidian are at very modest structures at the site, whereas some of the more fancy stuff has very little obsidian. So this got me thinking about sort of what's going on here, what mechanisms are responsible for this pattern. And by the way, this is the La Luna group, which also has a very high concentration of obsidian. And you can see it's quite a distance from the site core. So the first thing I'm going to share with you is would be the results of a PXRF analysis done by Hector Neff. And the sample consisted of 148 obsidian artifacts drawn from three residential groups, the Northwest Courtyard in the site center, Las Palmitas, which is an elite residential group, and La Luna, another elite residential group. And the occupations for all of these groups in terms of the obsidian that we're looking at it all dates to between AD 650 and 900, so late terminal classic. So the results of the PXRF analysis show that there are six obsidian sources represented in the sample, including three Central Mexican and three Guatemalan sources. And the latter Guatemalan sources comprise 98% of the sample. For the Central Mexican sources, you have Pachuca, Tulancingo, and Ucorreo, but all these are represented by a single artifact. And not included in this talk today, but back in 2012, Steve actually, excuse me, Mike did a PXRF study for someone at Zote's, and they found that there's also Otumba, and Zaragoza Oyamelis as well there. As far as the Guatemalan obsidian, it falls in line with expectations for sites in the central lowlands in that El Chayal is the excuse me, I think there we go, I should be showing you that. El Chayal is the dominant material by far, followed by Ishtapeque and then San Martín Helotepeque. And so this was a big, the major source in the pre-classic, El Chayal dominates throughout the early in late classic, but towards the end of the late classic and terminal classic, Ishtapeque starts to become more popular, but you can see it never surpasses El Chayal. As far as the central Mexican sources, during the late classic, they would have moved through, they would have arrived at El Zote's through inland trade routes, probably coming through or channeled through the site of Tikal, which controlled those routes. And then when you get to the terminal classic, you have a major shift in exchange routes where sort of the classic, you know, it's the class of my collapse, so sort of the traditional center of economic and political power, all those sites are going to decline and are abandoned and trade routes shift to the coast. So the Mexican obsidian would have come along the coast here to essentially Chichen Itza and then down south that way. When you look at the distribution of these different sources across these groups, you know, there is nothing that really jumps out, except for perhaps La Luna being the only group that has the Mexican obsidian. But again, we're just talking about three artifacts here. So how significant is that? In addition to the PXRF study, I also conducted a technological analysis of the obsidian. And what you're seeing here are, so we have three categories, bifacial reduction materials, core blade reduction materials, and then a general category, which was stuff that I just, I could not confidently assign to either of these technologies, though as you'll, you'll see momentarily I suspect most of this is related to bifacial reduction. But nonetheless, you have the Northwest Courtyard and La Luna from the PXRF study, and then some additional context with, you know, large samples just for comparison. And you can see that again, La Luna jumps out as being something different, something different is going on there, and that, you know, it's the only group that has significant amount of bifacial reduction debris and general debitage as well. So what is going on there? Interestingly, so you're looking at, this is a LiDAR map of La Luna, and Anna Bishop, who is a grad student at UCLA, is doing her dissertation work here. And while looking for Middens, very interestingly, she actually hit a debitage dump behind this structure right here. You can see, you know, the debitage and the profile here and then in the drawing, this is the lens right here. And, you know, in the Maya area, now this is not a universal law, but particularly in the late terminal classic, chert workshops tend to be associated with bifacial reduction, whereas, you know, obsidian is related with core blade. And again, that's not 100% positive correlation, but that that's the trend. So interestingly, we have these different, you know, the bifacial reduction debris and general debris in the obsidian amongst the obsidian assemblage, but in a context where, you know, you clearly have a lithic workshop. So, and you'll have to excuse me, I didn't have time to make beautiful drawings for you, so we had to do some highlighting instead. But what you're looking at here are materials from La Luna that, you know, I think, depending on your perspective, you know, they would be core blade. But I think, you know, these are all clearly related to bifacial reduction. And so what you have going on is that, excuse me, essentially, the nappers at La Luna are using obsidian cores, essentially as blanks to produce bifaces from. And so the green parts that I've highlighted for those who don't know, you know, these are all sort of those facets from blade cores that you can still see intact. And some of the stuff that's tricky, such as, excuse me, this piece right here, you know, kind of looks like it would be a platform rejuvenation flake. But the, you know, the platforms here and the angles so steep, it's really a alternate flake to set up that edge to start working the core into a biface. Interestingly, as well, this stuff is also at La Luna giving us an insight into the form in which the Mexican obsidian is arriving at Elzos. Particularly here, you have the one example of Pachuca, and you can clearly see the facets from the core. And then of course, the flaking from them, you know, turning this into a biface. And then this is the Ucarreo piece here as well. So sort of zooming out and looking at Elzos as a whole. One of the things that is very interesting is that the obsidian assemblage is almost entirely related to core blade reduction. La Luna is really the one place that does have some bifacial reduction going on. So when combined with the uneven distribution of obsidian across the site, and the fact that doesn't seem to be correlated with, you know, size of architecture or anything like that, that got me thinking about the possibility that there might be a marketplace or sort of market exchange. And one of the ways that you can look at this specifically for core blade reduction is using a really interesting model developed by Jason De Leon, David Carbio, and Ken Hurth, which is based off of Ken Hurth's sort of distributional approach to identifying marketplaces. The difference being here is that it's tailored for core blade reduction. And so they develop three models, one whole blade trade where, you know, self-explanatory, right? Whole blades are being traded sites. Another one, the process blade trade, you know, so complete, you know, blades are being produced somewhere else. They're being segmented before being shipped off to another site. And then you have local production, which can be, you know, resident artisans or even itinerant craftsmen. And I'll show you their lines of evidence and expectations momentarily as I wrap this up here. But a key component of this is production evidence. Is there production evidence present in the assemblage? And if so, what type is it? So they develop two types, primary production evidence, and that consists largely of cores and core fragments. And then secondary production evidence includes, you know, a wide array of things related to error correction, core rejuvenation, platform rejuvenation, what have you. So, you know, a lot of error correction blades and things like that. This may be a lot. I apologize. But you could certainly take a look at it afterwards or reference that article for more detailed discussion. But I won't go through all the expectations of these different models in detail. But I will show you sort of the aggregate of the L-zones obsidian assemblage from the late terminal classic. And we'll look at how it aligns with their expectations, and then I'll call it a day. So the first category, primary production evidence, right? So their expectation is that it, you know, it should always be absent in a context where blades are being traded into a site. Or an itinerary craftsperson is producing on-site because they're going to take cores with them when they're on-site because they're going to take cores with them when they leave. Of course, we don't have very much primary production evidence. Secondary production evidence, that's also a no for whole blade or process blade trade. But, you know, they recommend, rightfully so, that you need to look at this with nuance, right? So what type of secondary production evidence do you have? And at L-zones, the secondary core blade production evidence we have, it's all stuff that could be usable tools, right? You know, there are sort of percussion blades or, you know, crested blades, you know, things that are very much blade-like still that are useful tools. So those could also be traded. But the vast majority of the assemblage is comprised of late series blades, right? The end product of prismatic blade production. And then sort of the final kicker for me are these proximal distal ratios and medial distal ratios. And the important point here is that, you know, depending on core morphology, especially as the core gets smaller, the distal portion of your blade can be curved, right? So if you're trying to bundle blades to pack them up to move, it's possible that you will snap that curve and also that they can pack more efficiently. And so that's sort of what these expectations up here are supposed to represent. So when you look at those ratios at L-zones, I think all this sort of lines up to suggest that you have process blade trade where already segmented blades are moving into the site. And then folks are using perhaps interpersonal connections to occasionally get a small core to produce a bi-phase from. Okay. I'll leave it at that. Thank you very much. I'll stop sharing my screen. Okay. Thank you. Thank you, Josh. Do we have any questions? Yeah. As usual, I have one. Sure. So Josh, you were talking about snapping, transport snapping the tips off. Did you find those in the record? Did you find the tips of those things? Right. So are you talking about terms of the genesis of this model or this idea of snapping them off? No. Well, the idea of snapping them off, and did you ever find that in L-zones? Did you see it in the record? Or did they find it generally in Mesoamerica? Right. So they certainly do in some places at L-zones. No. I mean, there's almost no distal blade fragments at the entire site. And just for reference, I believe that De Leon and colleagues, their model was developed in the context of formative central Mexico. But I believe they drew on stuff from Archaic in the Tehuacan Valley, where I think they might actually found, they certainly found a hafted blade. I think they might have found a bundle blade segments rolled up in fabric, too. Well, early on, of course, probably nobody was looking for that either. Sure. Absolutely. Can I ask you a quick question? Sure. You're talking about this Elliott's site. And I was wondering, do you have any tools which were used for snapping? I mean, some kind of tools discovered, which you link to the, so you know that this was used for snapping, just for snapping. Sure. So I'll say no, we don't have any. But in the Maya area, especially when you get to sort of later stage bifacial stuff, like thinning by faces and whatnot, and folks move to softer hammers, whether it be wood or antler or even limestone, those things are going to be really hard to detect. Because of the environment, obviously, the organic stuff is probably not going to preserve. And it's just a harsh setting. So we have much better luck with hard hammers. You'll get like chirp cobbles that all have all the impact fractures, but etylzotes and particularly that workshop group. We don't have any tools, but I think you'd have to have a good eye to find them in the first place. Thank you. Sure. Thank you. Yeah, I would add, Josh, that the good evidence of workshop stuff, when you see these layering events, you know, people are picking them up from maybe a central plaza and then literally just layering it as they're depositing other trash around it. Right. Absolutely, Lucas. Great point. I mean, that's that little lens I showed you is very much, you know, it's probably 99% debitage with a few sherds thrown in. So it is a pure debitage deposit. Yeah, it looks like my backyard. Well, this is a time for a quick 10 minute coffee break just to kind of have a little bit of a break we can keep talking about. Josh's paper or revisit Guillermo's if we want to. Again, I'll remind you, feel free to use the breakout rooms if you want to have a private conversation. It's easy just to put in the chat. Hey, I'll meet you in room 10. Feel free to use those whenever you like. Anyway, this is a little 10 minute break that we can have and then I'll introduce the third Mesoamerican paper in about eight minutes. Anyone else have any questions? I'm happy to answer them if you do. Okay. Well, thank you, everyone. Thank you. Hey, Josh, if you're still on, I have a question for you. If you don't mind me asking you and in front of everyone here, maybe not. Maybe this is a good question for Guillermo. Do you have workshop evidence, Guillermo, with your work that you presented, or is it mainly sort of distribution of used goods? No, no. We have not evidence for a cleanup in workshops, but lapidari in obsidian, yes. Okay, definitely. Yeah, that was a big industry. You can see some of the course have been processed in many kinds, two made abrasions, and we have some artifacts that hasn't been finished in lapidari, some dog bits and cylindrical bits in process, but not finished. So we think that we have maybe a little bit of this processing, but just in lapidari, not in clean napping. Of course, there is some kind of refitted tools or something like that, but nothing that can tell something about clean napping or pressure processing of the blades, just one core and two prismatic blades. Josh, I was going to ask you one of those artifacts you showed look like a shoulder point. Was it the Pachuca one? Yeah, and I was curious if you'd read anything about stem bead points that Spencer ports on a long time ago, but the ones I've seen, they're all made on huge macro blades from Pachuca. You can see the ridge, the blade ridges or the ventral surface of the blades on one of the faces of the points. Yeah, that one, so yeah, I don't think, as you saw from the photo, I mean it was clearly a work in progress, and one of the sides, it looks like they completely destroyed it. It's hard to say what they were making. I don't think they were trying to replicate Teo point styles at all. I think they were trying to make a small Maya thin by-face, but the Guatemala National Project has just started pulling some Teotihuacan points out of Tikal again, just south of the Muno Paradido, and they're found alongside Maya points as well, and they're clearly different, just stylistically, not to mention the technological aspect. So I guess this is a long-winded way of saying that I don't think the Maya tried to copy those at all. I think probably when we see those STEM points, they're probably from Teotihuacan. Yeah, I've seen a reworked STEM viewpoint at Caracol. Oh, fantastic. The only thing that is in good proportion is the proximal end, but you can tell that the distal end was reworked. Very cool. Because it's fairly short, unlike the really long points that we have from other contexts. Very cool. Yeah, and I mean, you see that LaLuna context is interesting because it's the only time that I've seen Pachuca sort of used in, I don't want to say a wasteful fashion, but they're using a blade core to try to make a by-face. But yeah, usually when you find those Pachuca artifacts, it seems like they had such a long life history. I mean, they were broken, then they were resharpened. If they could no longer function as a point, then they turned into some sort of, not a flake tool, but some more sort of like a hand tool. So not surprising to hear they recycled that. All right, I'm going to go ahead and we're about a minute ahead of schedule, but I'm going to go ahead and return ourselves back to Central Mexico, more or less, and introduce our next paper, City and Exchange Fears and Late Post Classic as America, New Perspectives from Pachuca, Mexico Utilizing an Olympus Vanta Portable X-ray Fluorescence Spectrometer by Mark Merino, Lane Farrar, and Wesley Stoner. Mark, I have you take it away. All righty, thank you, Lucas, and it's an honor to be here, so thank everyone. I'm going to go ahead and set about sharing my screen really quickly. Okay, can everybody see that? Okay. Is that visible? Yes, it is. Okay, excellent. All right. All right, well, thank you again. Systems of craft production and exchange in Mesoamerica are often correlated with the sociopolitical circumstances in which they formed. In this paper, we seek to understand the place of Clash Calon and the Obsidian Exchange spheres linking it to other states through the vibrant economic networks noted for the Late Post Classic period in Central Mexico. Specifically, we tested Clash Calon, participated in the previously identified Obsidian Exchange networks noted for the Post Classic period, specifically the Late Post Classic period, and we investigate if any Clash Caltecan households preferred obsidian of a particular source. Why is this discussion significant? The organization of lithic industries, including the exchange of prismatic blades, is often reflective of broader cultural patterns. Previous research in Clash Calon has identified that models of Obsidian Exchange utilized for Post Classic Mesoamerica and applied to the Clash Caltecan polity were not entirely reflective of the consumption patterns identified from within the city. Instead, researchers noted that consumption of obsidian blades, a bulk commodity, followed the broader geopolitical strategies of the Late Post Classic period with a clear difference among the sources used in Clash Calon and those noted for other polities during the Late Post Classic. Ethno-historic accounts coupled with archaeological research indicates that the state of Clash Calon encompassed about 2,500 square kilometers and housed on the order of 250,000 to 300,000 people. The largest settlement within Clash Calon was the eponymous city of around 40,000 individuals. Systematic archaeological survey of this settlement mapped a densely occupied hilltop city covering approximately 450 hectares. Spatial patterns coupled with ethno-historic information from the early colonial period led Farger and colleagues to conclude that the city was organized in three districts that were subdivided into neighborhoods. Additionally, Clash Calon's ruling council consisted of an estimated 50 to 250 members presiding over a multi-ethnic population that in some cases were fleeing the Aztec Triple Alliance. Based on the size of Clash Calon, market exchange would have been a key provisioning strategy as it was for most Late Post Classic Central Mexican states. Market exchange of obsidian has been noted ethno-historically for Clash Calon and Huaychotzingo, its sometimes allies, sometimes enemy. And Cortez, in his second letter to Spain, noted that the largest Clash Calon markets received thousands of visitors on the busiest market days. Additionally, both Cerita and Motolinia also note vibrant markets existed in Clash Calon, with Motolinia specifically stating that the largest market in Okotoloco, one of the districts, was the most frequented location in the city. Based on these descriptions, Clash Calon merchants would have experienced high demand for bulk goods as they did in other places, including that of obsidian. Excavations in Clash Calon recovered large amounts of lithic materials and this paper only blades recovered in clear association with a structure or household context are discussed. Of those materials associated with a structural context, our sampling strategy consisted of selecting obsidian blades greater than two millimeters in thickness and including a sampling strategy of at least 10% of all obsidian blades recovered per household. Our final sampled amount was 1,343 blades. Of the structures that contain these lithic goods, one non-residential context is located in the Kiwishlang district, one other status household is located in the Okotoloco district, one high status household is located in the Tepitikpak district and two other households of other status are also located in Tepitikpak. Thus, each of the three districts are represented in our study and status contexts are represented by one possibly high status household, four other status households and one non-residential context. Methods for classifying the obsidian first entailed assessing the Olympus Ventus factory calibration. I'm not going to show everyone all the regressions that went with this but this was accomplished using the Mer Obsidian standard source library. 40 artifacts were saved five times each at Mer and the reliability and error was assessed. The final elements that were suitable for analysis both due to their reliability and their accuracy and that were known to work well in Mesoamerica, totaled five and each was subsequently calculated as a ratio to zirconium following some of the recent and relevant literature. Next, 98 source materials from 15 Mesoamerican volcanic sources were assayed as reference materials. These were again calculated as ratios to zirconium for the same five elements. Classifying the actual obsidian samples excavated excavated from classical lawn and analyzed by the Vanta, PXRF was accomplished using myhalinobus distance as part of the Gauss statistical software package and also using the data manipulator tool of the same software package. Following after that principal components analysis was also used to assess the effectiveness of this method and later reference groups were also tested with a manova using the past statistical software package. In total nine samples were left unassigned. Some of them were assigned however they did not represent enough in terms of actual samples to comprise a statistical group so we just left them unassigned for that case. But all groups were statistically significant according to the manova meaning they were all statistically distinguished. Except for the mouth by e source excuse me which again since it only had 202 samples not 200 it could not be tested using manova. This source is far removed from the others however in terms of compositional space. Okay so our site white patterns both confirm and discredit old models on one hand previous research in classical lawn is confirmed as classical technical sources and not Aztec sources are the primarily consumed obsidian tools. Paradone a source that is located outside of Aztec purview is the most frequently utilized source of raw material. The presence of large amounts of production related debris which is not discussed here but has been discussed in previous papers and publications attests this material being brought in as worked nodules. The second most utilized source is Pachuca not the first with a tumba the other primary Aztec source for the late postclassic being the fourth. This is surprisingly this is surprising given that they're usually consumed in much higher frequencies than late postclassic central Mexico. When households are compared individually and those are five households interesting patterns emerge first again Pachuca obsidian is not the highest consumed source instead Paradone is overwhelmingly consumed among households. The one household that does consume the most Pachuca and a tumba obsidian comparatively has been previously shown to be producing blades and some tools for extra household consumption during the late postclassic thus this pattern might simply reflect the higher amount of prismatic blades moving through this structure. Further all sources are utilizing Paradone obsidian above frequencies of 55 percent which is the lowest they usually range 60 to 70. Ogletolocal structure one is again using the least amount of Paradone obsidian that's the 55 percent but all structures are still using it at a rate of two to five two to four more times than other sources. The non-residential structure in Kiwishlon consumed slightly more of the Paradone source. Lastly some households do consume a statistically higher percentage of some other sources over others for example Ucareo typically appears in very trace amounts ranging from zero to 0.79 percent in four of the five structures tested however at Kiwishlon it appears at a higher amount of seven percent likewise Pachuca is the least uh is the lowest amount consumed in the Kiwishlon context and again Paradone is the highest amount consumed in this context. So as a wrap-up examination of the exchange networks connecting Tashkulon with the Greater Mesoamerican World System revealed interesting patterns in the long-distance exchange of non-local obsidian at this site. First Paradone was the highest consumed good at the site and its consumption among households is likely or will likely be statistically significant as soon as we run the tests when compared to other sources. Second Green Obsidian at the site was found widely distributed across the city by the survey project headed by Barger, Heredia and Blandon. This pattern is again supported by the frequency of obsidian found within households and excavated areas however this does not mean that all households are consuming every source equally as some households do consume slightly more obsidian Pachuca in the case of Occulto-Local Structure 1 or a statistically higher amount uh Ucareo at the individual household context for example at Kiwishlon. We believe this is a good jumping off point to assess the patterns more fully at a later date. Lastly access of all households and structures on all terraces these lithic materials likely reflects market exchange. Okay so in conclusion in his description of the Occulto-Local Market in Tashkulon Cortez notes that trading exchange occurred both within the central market and at various other marketplaces plazas throughout the city. Field survey and excavation data supports his descriptions yet it is clear that obsidian procurement and trade played a key role in provisioning households with this bold good and current models do not highlight the importance of the Occulto-Local Caldera also known as the El Paridon Obsidian Source in provisioning the residents of the Tashkulon quality. So where does Tashkulon fit into currently post-classic models of obsidian procurement in exchange? Based on the survey and excavation data the size of the polity and the amount of Paridon Obsidian consumed by households again 55 to 70 percent per household we believe Tashkulon represents a significant consumption sphere in and of itself utilizing primarily and comparatively uniquely for this time period the El Paridon Source and other sources within the broader Mesoamerican world system. So with that I'd like to thank several people I'd like to thank Aurelio Lopez of Ina Toxcala specifically for taking us to the Paridon several times for active research and by that I mean the the volcanic source El Paridon. I would like to thank the Murr Archaeometry Program which helps support and fund this project. I would also like to thank the Sturgis International Fellowship at the University of Arkansas for the same reason for support and funding as well as the Tashkulon Archaeological Project in Lane Farger and Mexico's Connoissee and that is all I have thank you so I will stop sharing okay. Thank you Mark. Absolutely thank you. Very well we have some time for questions. Yes sir. I have a question Mark. Yes sir. Ukareo seems an outlier for me. What do you think about this particular source? In Kiewislan there is a good stratigraphic control or maybe just a surface findings on this materials. What do you think? Well being I actually helped excavate Kiewislan so I would of course I was a supervisor I wasn't necessarily the PI who was a very good friend of mine however and so I would I would like to say that we have a very good stratigraphic control. One thing I will note also Ukareo is definitely a very unexpected and a very interesting outlier. We all agree to you with you on that one. This is very recent very new to us as well so we're interested in that but I will say that there are several ethno-historic accounts of a connection between Tlaxcalon and the Tarascan Empire in terms of you know one of the main generals obviously went that way. So we it's something that we're interested in and we're actively pursuing. We also have some ceramic data that we analyzed with neutron activation analysis at MIRR so maybe that will shed some more light on these exchange patterns. Thank you very much. Thank you. Mark I'd be interested to see your regression lines for your instrument. I will absolutely send them to you honestly there was just too much there was just you know it was overwhelming all the all the figures and data. I just didn't know how to streamline it but perhaps that's. Yeah those those things can can really be cumbersome to show but the fact that you're reporting that level of rigor is a good thing. Oh well thank you yeah and anyone that's interested in seeing them I would be more than happy to have a very long and probably boring discussion about it. I love it so okay well. We're a few minutes early I don't want to start our next paper too early give people time to enter and listen to various talks. Mark I was wondering about the the other calibration method the Pyro that Ellery's circulating because that I know that when you don't have empirical calibration options that one's and that's a possibility for sort of sort of after the fact calibration right for like the spectra that are produced with fundamental parameters which I assume that's what the Vanta gives you. The Vanta does use fundamental parameters there are ways to do an empirical correction right so you can correct the data in a very similar way to when you're calibrating an instrument. Obviously it's not exactly the same but there is a way certainly to do an empirical correction which I ended up constructing at Mer. I opted not to use that correction in Mexico specifically because I was just concerned that with travel it would it was just easier and faster for me to be able to just run the data assess error assess precision which is arguably one of the most important things you can do immediately rather than you have to understand too this was sort of at the height of when all the craziness of the last year started so it was just easier to immediately assess precision and accuracy of the fundamental parameters calibration rather than utilize a correction just for the sake of convenience really but again using the fundamental parameters calibration itself after assessing the error and the accuracy using standards there was it was especially for obsidian it was very negligible all of our regression models to those standards which of course were run with neutron activation analysis other pxrf la icpms and probably another form of icpms to be honest and this was constructed at Mer I should also say basically they were all in the high 0.9s I believe one of them was maybe 0.98s um but I want to say that was zirconium but um yeah we had a very very good calibration I mean honestly that I also was utilizing Mer's broker uh and with that of course you have to construct your own empirical calibration and some of the uh I didn't use that in this project but the the regressions that I was getting on that were very similar to the Vantas in this case great well Mark Mark first of all you used the geochem model in Vanta yes sir okay sorry maybe I should have said I apologize oh maybe the Vanta is a little more rugged than the tracer I've already had issues with our 5i oh I can't comment there so I will not all right well thank you very much Mark yes sir thank you for asking questions yeah instrument performance is a is a key issue for all of us um that's sort of underlies everything we do so I appreciate that conversation our next talk uh networks of procurement and provisioning geochem evidence from late classic katsumu walpa Guatemala by David McCormick looks great David sorry I guess when you didn't answer it I guess you didn't you couldn't hear me okay all right um there we go um I'm just gonna start with uh showing you some of the kind of the land that we work that I work in here this is uh the view from Kotsumu Wapa it's kind of a very lush agricultural area um it's in the modern modern Esquintla Guatemala the Piedmont zone of the southern Pacific region which I'm going to refer to uh going forward as the SPR of Mesoamerica uh Long recognizes a corridor of interaction this is a resource risk zone uh and it was precocious in Mesoamerica's cultural trajectory it's no surprise that it witnessed demographic transformations involving merchants migrants amicable and hostile who left their imprint on local populations this movement of people and ideas manifested itself in novel cultural forms based in both local ante scenes and foreign concepts Kotsumu Wapa culture is but one of these manifestations like uh it's like anography and distinctive sculptural corpus which is best known for demonstrate a complex blend of both local traditions traceable to the late formative a rejection of early classic Teotuba con related enclave dominance in Esquintla while balancing a concern to demonstrate widespread networks of elite culture extending throughout other regions of Mesoamerica Kotsumu Wapa participated in long local ceramic tradition sorry uh whose distribution was much larger than that of the site sculpt uh sculptural style imported certain uh imported ceramics also indicate ties with the Socanusco region and along Mexico Guatemala border the Alta Verapaz the Lake Atiglán regions of the Guatemalan highlands the Lua Valley of Honduras and southeastern Mesoamerica more generally from the volcano from its volcanic peaks of this Sierra Madre to the Pacific Ocean the people of the SPR were economically interdependent on zonally restricted resources of the coastal plain Piedmont and Highland zones while the Piedmont abounds with thick nutrient rich agricultural soil and volcanic stones such as basalt nanocyte for making grinding implements it lacks local tool grade stone for cutting edges like the Chert and Calcetani of the Maya loans people of the Piedmont and coastal plain were entirely relying on imported material to meet social demand for cutting edges and they did so almost entirely through the importation of Guatemalan Highland obsidian sorry and here's the kind of zone that we're talking about here um and you can see here it's kind of um blocked off from the rest of what we know is the Maya region right uh from the volcanic ridge and the and the low and the most local uh and most utilized uh areas uh sorry sources of highland obsidian the modeling of obsidian exchange has uh been oversimplified into two main trade routes in the SPR one of these is the one of these routes moves El Chail obsidian purportedly through Caminal Huayu south through mountain passes around Lake Lake Amatitlan through the Piedmont and down to the coastal plain where it then moves west towards the Suconusco the second route begins at San Martín Hila Tepeque and moves west along the Highlands into the Chiapas Basin where significant portions of material descending through mountain passes to the Piedmont sites of western Guatemala a third exchange system exists on the eastern portion of the Guatemalan coast where ish Tepeque predominates and that's over here um we'll see that this is problematic in an oversimplification very quickly so we start in the early formative um wherein the kind of precocious uh uh social development necessitated the establishment of long-distance change networks um and although our early formative uh data is limited and spatially discontinuous um with most of the data coming from the Suconusco which I don't show here but which has been done by Clark and the colleagues um it's clear that this time significant amounts of San Martín Hila Tepeque and El Chail obsidian were circulating through the SPR primarily in east to west trend. Tahumoco also became an important source of obsidian in the Suconusco but its exchange into Guatemala is very limited but you can see it is um an important source here in Salinas, La Banca although this is a rather small sample size um uh during the middle formative um I have even more kind of spotty and uh more discontinuous information and the less of the material can be securely kind of um designated to the middle formative but you can there's a lot of kind of overlap I guess with uh late formative uh sites here as well but uh sites across the SPR during this period continue to move the aforementioned obsidian sources material from Ixtepeque has been recovered from as far west as La Banca during this period near the Guatemala-Mexico border uh where and it also imported uh sorry during the later facet of this period the site of El Oshuxte grew in the western Guatemala and imported substantial amounts of San Martín. Further east Chail is the primary source of obsidian exploited although Ixtepeque appears in higher frequencies moving uh as you as we move east from the central from central the central Guatemalan coast into the eastern coast of Guatemala. During the late formative we have substantial collections uh kind of throughout the SPR but most of those unfortunately most of those await geochemical analysis um there has been significant amount of visual analysis done but uh you know there's obviously lots of problems with that during the late formative that we know that there's intensive interaction among the emerging polities um and kind of are seeing the first uh what we would call cities I guess this is uh we have a kind of emerging uh sculptural corpus throughout the SPR especially along the highland here kind of through uh the Piedmont and into the highlands going all the way up into Camino del Huayu uh where you have kind of the um concerns of rulership and the use of writing beginning to emerge and this includes the uh a long-distance exchange of obsidian as well. Two well-studied sites from the western Piedmont noted for a shared sculptural corpus also demonstrate similar consumption patterns. Rebekah Mendelsen's recent work has demonstrated differential patterning in the distribution of sources in blade versus non-blade obsidian at uh Izapa and while Tawamoko Obsidian dominates the non-blade assemblage, San Martín dominates the blade assemblage. Visual analysis suggests that San Martín dominates the Piedmont of Takali Kebab. This is the visual analysis of love although Krasborn presents evidence to the contrary. You can see they uh that these two analysts disagree. However, if the frequencies reported by these two analysts are similar to the blade frequency frequencies reported by Mendelsen for Izapa if they're if those two are if they you average those two um um visual analyses. Along the Guatemalan Mexico coast, El Hoshuk's day's assemblage is dominated by El Chayal. The importation of San Martín is substantial and accounts for about one quarter. Moving to the central Guatemalan Piedmont, the coast and the coast the data suggests the complicated more complicated picture of exchange. The Piedmont site of El Balsamo skews slightly for San Martín and 56 to 50 with 56 percent and 44 percent for El Chayal. Coastal plain site assemblages are dominated by by El Chayal but you can see to a varying variable extent. Oh sorry. Okay during the early classic we can see that there's a number of a number of changes occur. You have a again the visual analysis of Krausborn suggests that Chayal is dominating in Tacalicabach. Izapa is still being dominated overall by by San Martín in the blade category and Taumulco overall but you have the incursion of Teotihuacan related people coming in to Valberta in the on the Esquintla coast during the early classic and then you have you have here the appearance of green obsidian and but an almost exclusive use of Chayal obsidian in favor of uh in favor of San Martín, Orish de Peque. This changes kind of in the late facet of the early classic or if you want to call the middle classic when you have the sites of Montana Los Chatos and Manantial which are all related and probably part of the same polity as Beauvais suggested and they are important they're using primarily Chayal again but they are using significant amounts of San Martín and also importing significant amounts of Isch de Peque obsidian. Important to note that during this period there is no evidence of blade production at least on the coast. You do have bipolar industries being practiced at Valberta and likely elsewhere. Okay so these slides got messed up. So during the late classic you have Kotsima Wapa rising to prominence kind of in the wake of Montana Manantial and Los Chatos this is fall and it's the center of a three-tier political system where you have Kotsima Wapa here at the center blown up here and we have two kind of tier two sites followed by a number of tier three sites and here I'm gonna present the data from excavations that I undertook at dumps A and F. Some excavations done by my advisor at dump D and some work that was done in the 1990s by Fred Beauvais at dump G. Each dump is pretty gonna present a separate as you can see each dump presents a different profile obsidian profile and what's important to see here is that each one not only is using is constructing out of different frequencies of different material but some are essentially ignoring San Martín altogether or not utilizing San Martín the San Martín procurement network at all. And interestingly here dump A there's a significant amount of San Bartolome Milpas Altus which is a rarely ex rarely exploited source and and the material that I found there from San Martín or San Bartolome Milpas Altus is actually certainly bifacial thinning flakes so they're making bifaces out of this rarely rarely exploited source. Dump G is the only one that's basically making only blades and it is all is basically 75 you know almost 75 percent or it gets 70 percent San Martín which is interesting up in and of itself as we are going to look at the the the consumption context that don't really match up with how the material but how the dump the material the obsidian frequencies of the dumps were spatially distributed. So switching to consumption contexts of the Kotsomal Wapapolite we see in symmetric thing patterns. Various assemblages from elbow wool operations are all dominated by El Chayel obsidian but the degree to this of this dominance varies on the low end from 64 percent to 91 percent on the high end. Most assemblages in Kotsomal Wapapolite are proper dominated by El Chayel including El Castillo, La Gloria and Veral here kind of in central central Kotsomal Wapapolite. However San Martín dominates context around Bilbao which is the which is the the southern kind of acropolis. The few peripheral sites we have data from demonstrate a preference for San Martín at the northern sites of Palo Verde and Los Suyos while El Chayel is preferred at Finca San Cristobal. None of the evidence suggests that any one consumption context was reliant on centralized distribution systems or exclusive relations with particular workshops. We also do not see a totally homogenized distribution of obsidian sources which we might expect with open market models. Workshops would be the logical provisioners for the areas immediately surrounding them and this notion is supported in the high frequency of El Chayel obsidian recovered from around dump F and and the ball court some hundred or so meters distant. However a simple decay model from these workshops is not supported as non-dump obsidian from operation EB-15 which or EB-14 sorry which is exactly which is where dump A is consisted of nearly a quarter San Martín and dump A has no San Martín debitage. Likewise obsidian frequencies at EB-4 and the elbow will acropolis are nearly identical differing significantly from the closest workshop dump D which had about a 50-50 ratio. At El Castillo the difference in frequencies differs in from frequencies recovered from dump D favoring El Chayel instead of San Martín. Certain obsidian sources may have been favored for particular tasks over others and a dedicated study of use where may illuminate such preferences. It may also be that some households within Kutsumawapa received more or less of their obsidian tools from non-Kutsumawapa workshops. This seems likely for the peripheral sites of Suhuya and Palo Verde as they are located on the natural north they are located north on the natural mountain pass that leads directly to San Martín. However Kutsumawapa produced obsidian tools at a level that far outpaced demand for their city and their immediate inner land. Looking at Kutsumawapa as a whole it seems that they are they are similar to their predecessors on the coast and engaging in exchange of two primary sources. They distinguish themselves in producing tools on a large scale something that is generally restricted to the Highland quarries in the Guatemalan portion of the southern Pacific region. Additionally prior to late classic Kutsumawapa only a single piece of San Bartolome, Milpa's altos obsidian has been identified. Although it represents only one percent of the sites assemblage at Kutsumawapa this presence particularly in manufacturing debris or this rarely used source significant endpoints to close ties with the Antigua Valley where Kutsumawapa sculpture has also been found. There is a significant reduction in the importation of Ishtepeke obsidian compared with late and early classic or middle classic sites of Montana, Mandantial and Los Chatos. The presence of no less than six obsidian sources within the Kutsumawapa proper an unidentified source as well as Laguna, Yarsa and the sites the aforementioned sites of Ishtepeke, San Martín, San Bartolome, Milpa's altos and El Chayal points to cosmopolitan nature of the city and the maintenance of ties with people who are bringing exotic obsidian in as Richard spoke about earlier for the Andes. It may be significant that Kutsumawapa's location is at the approximate latitude as the late formative site of Los Cerritos Sur where Beauvais identified significant evidence of production but no sourcing studies have been done. Whatever the case Kutsumawapa workshop artisans took advantage of trade in both El Chayal and San Martín obsidian to provision themselves with raw materials to manufacture prismatic blades and projectiles. It appears that although access to Finnish tools was not restricted to the raw materials and perhaps the knowledge of production was and that Kutsumawapa's obsidian artisans were of a high status but that is a story for another day. Thank you David. Time for a quick question for David for anyone. All right with that I will go ahead and introduce our next paper. New XRF Prevenience Research on the Obsidian Drury from the Great Temple of Tenochtitlan from Emilio Malgaard Tisco, Guillermo Acosta Achoa, Victor Garcia Gomez, Riana Solis Ciraco, Luis Cova Morales, and Eder Barhar Laguna. Thank you so much Lucas. I really appreciate that you permit that we will present these new results of the last X-ray fluorescence provenance analysis of obsidian lapidary objects from Tenochtitlan. This is a result of a collaboration with the Temple of Major Museum where I work and with my co-authors Guillermo Acosta that presented at the beginning of this symposium with the UNAM, the National University Autonomous of Mexico. So this is one of our first results before the COVID. Well, so let's go on. The Mexica more widely known as the Aztecs were fearless warriors who conquered and dominated different regions of ancient Mexico receiving tribute payments and practicing ritual sacrifice and the capitulation of victims and enemies. The capital town of the Mexica was Tenochtitlan built on a series of islets near the western edge of Lake Descoco in the basin of Mexico. You could see here in central Mexico. The Mexica founded the city in AD 1325. Its center was the sacred precinct world of square area which housed the principal buildings and the most important structure, the Great Temple, known in Spanish Templomayor. Here you could see the Templomayor or the Great Temple, the surrounding structures and we are close to the main cathedral of Mexico City, the modern Mexico town. From the foundation of Tenochtitlan on AD 1325 until the arrival of the Spanish conquerors on AD 1520, the archaeologists identified seven constructive estates at this large stepped pyramid. You could see, well, because this is a project that burned or started at 1978. Well, other colleagues from a museum detected seven estates or construct constructive estates and related with that chronology and the correspondent Tenochkan was the name of the ruler or the Aztec was the Mexica king because Aztec is not a very good term. The Great Temple was their most famous cult center with a double staircase leading up to two twin shrines, one dedicated to Tlaloc on the northern part of the Templomayor and the other to Witsilopochtli, the war god. These two gods represented the Mexica's most fundamental economic concerns, agriculture and tribute. So you could see, well, it's interesting that the Templomayor has these two main gods, but also there are other estates that they gave offerings for their ritual and sacrifices for them. Both aspects were reflected in the more than 100 offerings associated with the Great Temple. Inside them, the archaeologists recovered thousands of objects from different provenances and raw materials. These wealthy contexts include local crafts, goods from tributary regions, relics or artifacts belonging to cultures prior to the Mexica, and found all remains from diverse ecosystems. Since 1978, one of the main goals of the Templomayor research project is the material characterization and manufacturing techniques of the goods recovered in the offerings to detect similarities or differences among the deposits, chronological changes, and cultural provenances. In the case of obsidian objects, there are hundreds of pieces with different morphology and aesthetics deposited in almost all the constructed estates, covering the stage 2nd AD 1375 to 7th stage, AD 1520. So you could see we have lapidary items, another ear flares, but also we have flaked scepters, other kinds of prismatic blades, and points, for example, and we have different kinds and quantity of these obsidian items in the offerings. Among the assemblage, the archaeologists have been recovered more than 1000 artifacts of cheap obsidian or flaked obsidian, but only 210 pieces of jewelry. So you could see there are more research about the flaked pieces from Templomayor than on the lapidary pieces because the minor quantity of them. The obsidian lapidary objects at Tenochtitlan include urns or funerary urns because some colleagues found cremated bones in two of these urns, blades, beads, pendants, ear flers, scepters, nose plugs, and pectorals, among others. We know that based on the iconography of the catexes and other written sources of the 16th century, we know that, for example, this scepter, this cylindrical scepter with global finish, like this one in a tiny model, are for one of the pulque or a beaver ash god of the Nahuatl people. Also, we have this nose plug in the form of two tongue of serpents. That is one of the emblems of Shippetotech, one of the gods that deflate the skin of the victims, or the circular ear flers that is one of the attributes of the wind god, Hegel Kezelkoad, for example. But also we have, interestingly, in different color of obsidian, this reddish brownish obsidian, all the pumpkin beads, lobular beads, and in a mixture of green golden obsidian, gray obsidian, and reddish brownish obsidian, these helical beads, for example. The morphological and tracheological comparison of these objects with pieces from other sites, confirm the presence of different lapidary traditions in the assemblage, like beads, ear flers, and leverage. Some of them resemble artifacts found in ancient archaeological sites, like the pectorals from Tula, so they could be relics. For example, we have this is one of the circular pectorals that we have in Templo Mayor, and other archaeologists at Tula found these the same shape and with the same golden obsidian, in this case, the same raw material at Tula, a former or earlier culture and site. Also, we have labyrinths, like in other parts of central Mexico, also around Mesoamerica, but with different shape and without drill holes that we have in other collection in the basin of Mexico. And interestingly, only these common ear flers that in obsidian are one of the most common pieces on lapidary in post-classic Mexico, they are absent in the imperial stages of Tenochtitlan. So these pieces, at least with the known offerings that the archaeologists excavated, are absent and perhaps the lapidary artisans of the Tenochkan people didn't know how to craft these ear flers, because they are absent in the imperial stages, in the earlier stages where when they are the warriors or the mercenaries of the polity of the Panic Azcapotzalco, the offerings have all these kinds of ear flers. And you could see with our translational analysis that is not the purpose of this talk, we found different surfaces produced by abrading with basalt, polishing with sand, and brightening with leather, abrading with basalt, polishing with calcedoni, abrading, excuse me, brightening with leather, abrading with andesite, polishing with chirped nodules, abrading and brightening with leather. So we have found different kinds of techniques, and we have different lapidary traditions among the obsidian lapidary objects. Also, we could identify these differences in diversarial materials, morphological and technical differences among similar pieces in contemporaneous sites with Tenochtitlan, reinforcing the existence of different craft groups. Related with that, the local and exclusive production of some of these goods at the sacred precinct of Tenochtitlan are reported in the written sources in the room at the Tenochkan Palace, Totokali, was appreciated even on the common jewelry found at the Tenochkan capital, like labrets and dock pendants, because they are different in shape and raw material, and also in technology in comparison with similar pieces from other sites of the basin of Mexico. Again, you could see the technological, also some kind of the shape, and also the color of the obsidian among contemporaneous sites. It related with the obsidian colors, the pieces show greenish, golden, reddish-brownish, and grayish colors. The 177 green-golden pieces came from the Sierra de las Navajas or Pachuca source because its particular color, but the other 33 objects, four dark gray, 13 translucent gray, and 16 reddish-brownish pieces required more analysis to identify their sourcing areas, because earlier researchers proposed that almost all of these pieces came from Otumba source, and the dock pendants came from Paredon, for example, but we will show you that they are not from these sources. Surprisingly, during the 43 years of excavations at the Templo Mayor project, only one archaometric provenance study with neutron activation analysis had been carried out on six objects, none of them like lapidary, five prismatic blades, and one flake. Three of them were green-golden obsidian from Sierra de las Navajas, two gray and one red-brown from Otumba, and one gray from Saragosa. Unfortunately, it is noticeable the absence of archaometric provenance analysis on obsidian lapidary objects from the Great Temple of Tenochtitla. Based on the scarcity of provenance analysis on lapidary items, especially on reddish-brownish and grayish colors, we chose a sample of pieces from four offerings from different stages and with a diverse type of object. You could see we chose offering 14, offering 34, 39, and offering B from this, because this is one of the two offerings with obsidian objects surrounding the Great Temple. As you could see, almost all the pieces of this offering came from this tohylplomb, false tohylplombite, or a fake tohylplombite vessel, and the other, this is offering 39, concentrated one of the most, or the quantity, great quantity of earflare, beads, and pendants of Templo Mayor. This sample includes 19 pieces, beads, pendants, arms, lids, and scepters. The beads and pendants concentrate the grayish-reddish-brownish colors among the assemblage. The others are green-golden pieces, so you could see the different type of objects, the offering, the constructed stage, the roller, and the color of the obsidian. As Guillermo Costa, my co-author and colleague, showed at the beginning of this symposium, we used the same equipment in this work. We will present the results of the recent analysis with portable x-ray fluorescence applied on these 19 obsidian lapidary goods with different morphology, function, temporality, and color. We employed the broker tracer with the same parameters to analyze 10 elements, and for the validation we used the obsidian reference standard NIST 278. We compared the results from obsidian sources of the reference assemblage collected systematically by the laboratory for history and evolution at UNAM. And for this research, we compared specifically the results from phenostitlam pieces with 16 obsidian sources of the trans-Mexican volcanic belt, because we didn't found any guatemaltech sourcing pieces. We compared the results obtained with the portable XRF equipment and the statistical study by analyzing the main components, PCA, of the obsidian artifacts from the Great Temple, compared to geological samples, allowed us to define that five of the 10 elements analyzed, yttrium, rubidium, strontium, cerconium, and neobium, are the most significant to define the provenance. However, it was also possible to observe two different sources that were better defined by another statistical analysis, gearchical cluster analysis. This allowed us to clearly group three objects, the dog head pendants, as coming from the picodorisava source, remember other colleagues proposed only by optical analysis, they came from paredon in Veracruz. In the case of the picodorisava source, another one, an helical bead, was made with gray obsidian from Ucario-Mitracan. Based on that, we could determine that most of the samples belonged to the main deposit of the basin of Mexico, of Otumba, the sub-source, Buenavista, and Pachuca, a common sourcing pattern among the ascent blushes of central Mexico during the post-classic period, AD 12,000 to 1521. However, two distinct deposits were defined better with gearchical cluster analysis. Three objects came from picodorisava in Veracruz, and one piece from Ucario in Mitracan. The interest of the Mexica on the picodorisava source was important for the military garrisons located about 20 kilometers from the mines, and also with the TISOC, one of the rulers of Tenochtitlan, that tried to conquer central Veracruz. In contrast, the Ucario material was an unexpectedly resolved because this source was unusual in the basin of Mexico, at least in the Mexica times due, probably, to the dominance of the mine by the Torazcan Empire in west Mexico, one of the principal rivers of Tenochtitlan. This object could be a relic obtained by looting ancient sites of the basin of Mexico, as Guillermo showed us, is a helical bit, in the case of southern basin of Mexico, with prior occupation or as a gift or a war price. Finally, it would be the first reported material originated in west Mexico in the great temple ascent blush. As concluding remarks, based on the XRF provenance analysis, we identified four sourcing areas for lapidary objects, Sierra de las Navajas for green-golden, Otumba subsurge Buenavista for the brown-red color, picodorisava for the translucent gray, and Ucario for the dark gray. Sierra de las Navajas was the main source controlled by the Mexica, while Otumba was the nearest source. The Mexica controlled its distribution through markets and workshops. Interestingly, obsidian was absent in the imperial tribute list, as Guillermo showed earlier in this symposium. There are two new records in the obsidian provenances at the great temple, picodorisava for the translucent gray, and Ucario for the dark gray, both located outside the basin of Mexico. Picodorisava was important for the Mexica, as we told, because of the military garrisons about 20 kilometers from the source and for the Tizoc campaign against central Veracruz, while the Ucario obsidian was the most unusual and unexpected source located in west Mexico under the control of the Tarasca, and this is the first record among the Tenochkan Assemblashes. This research would not have been possible without the collaboration and participation of different colleagues and institutions. Thank you. Thank you Emiliano. Well done. We have any quick questions for Emiliano and colleagues? Thank you very much with that. Our next talk is the pre-recorded one. I will be responsible for playing that titled Mesoamerican Obsidian in the American Southwest. What it means for Southwest Mesoamerican Connections and Coronados Mexican Allies by Sean Dolan. Hi everyone. So the paper I'm presenting today is based on a presentation that I first gave at the 2019 SAA in the Frixell session honoring Steve Shackley. Since then I've added additional content and data. Now I don't include everything in this presentation today given the time limit, but Shackley and I submitted this research to American Antiquity and it's recently been accepted for publication. So the full paper will be available out sometime later this year if you're interested. So wait for the movie. So one of the most enduring and debated research topics in American archaeology over the past century has been the scope and scale of interaction and trade between the United States Southwest, Northwest Mexico, the Southwest Northwest, and Mesoamerica. Some argue that Mesoamerican agents greatly influenced Southwest Northwest cultural evolution as specialist long-distance merchant spies or Pocheteca infiltrated places like Chaco Canyon and Casas Grandas to establish northern trading outposts. Now others challenged that position and maintained that culture evolved independently because both regions had their own unique and situ histories. However, one cannot ignore that Southwest Northwest groups acquired objects of Mesoamerican origin like copper bells, cacao, marine shells, scarlet macaws, as well as ideology, iconography, and Mesoamerican-like architecture. If people in the pre-Hispanic Southwest Northwest acquired chocolate drinks, colorful feathers, and horned serpent deities from further south in Mesoamerica, did they also acquire obsidian from Mesoamerica? As we all know, obsidian is an excellent raw material to elucidate and track Southwest Northwest Mesoamerican connections because each obsidian source on the landscape has its own unique geochemical signature. Although people moved obsidian across diverse environmental and cultural regions of North America for millennia and archaeologists have analyzed tens of thousands of obsidian artifacts from pre-Hispanic Southwest Northwest sites, Mesoamerican obsidian from confirmed pre-Hispanic Southwest Northwest contacts has yet to be found and reported, with few exceptions Southwest Northwest groups only used obsidian from New Mexico, Arizona, Chihuahua, and Sonora. However, here in this presentation I discuss the implications and significance of four green obsidian prismatic blades and blade fragments recovered from four sites in New Mexico and Arizona. Now here in the Southwest Northwest, green obsidian is relatively uncommon in this region and pre-Hispanic groups didn't manufacture prismatic blades. Therefore, these four obsidian artifacts are an anomaly when viewed alongside typical Southwest Northwest chipstone assemblages. So it's essential to determine from which source they derive. Shackley used EDXRF spectrometry to determine the source and his analyses confirmed the four blades match the geochemical signature of the Pachuca source from Hidalgo, Mexico and Central Mexico. Three of the four artifacts were first reported elsewhere with minimal discussion. They were in cultural resource management project reports and they're relatively unknown to most Southwest Northwest and Mesoamerican archaeologists. I contextualize them here because they're the only known Mesoamerican obsidian in the Southwest Northwest. However, instead of coming from pre-Hispanic sites that have numerous Mesoamerican interaction markers like Chaco Canyon or Casas Grandis, they were found at sites that the Spanish and their Mexican Indian allies used or potentially visited beginning with the Coronado expedition of 1540 to 1542. In this presentation, I first briefly introduced the four sites and artifact sampled and then I present the EDXRF results. Using the EDXRF data, lithic technological organization and historical narratives, I assess the credibility and likelihood of the different hypothesized models of pre-Hispanic Southwest Northwest Mesoamerican interaction and obsidian use by the Mexican Indian allies. Based on the available data, Mesoamerican obsidian is not a marker for pre-Hispanic Southwest Northwest Mesoamerican interaction. Instead, Pachuca obsidian is a time marker for 1540 and later in this region and provides evidence that Mexican Indians were likely present. This study also contributes to the complicated and long-distance relationship between the pre-Hispanic Southwest Northwest and Mesoamerica by addressing interaction and trade and the extent of Mesoamerican influence on Southwest Northwest groups after 900 CE. This study also provides new perspectives on the material culture of the Mexican Indian allies of the Spanish who are a very much underrepresented group in the archaeological and historical records. Site LA54147 is in Bernalillo, New Mexico and archaeologists excavated the site in 1996. Brad Vieira makes a strong argument that members of the Coronado expedition camped at the site because the pottery assemblage provides an approximate date of 1525 to 1625 and metal artifacts and domesticated sheet boner found. Three radial carbon dates also support a 16th century occupation. A green obsidian blade fragment was recovered and Robert Santly visually identified the source material as Pachuca and Bart Olinger used XRF spectrometry to confirm. LA80,000 is in downtown Santa Fe, New Mexico next to the palace of the governors, which was built in 1610. During excavations, archaeologists found intact cultural deposits from the late 17th century and so the site may have been used during the 1680 Pueblo Revolt. A green obsidian blade fragment was recovered and Stephen Lentz says it's from the Pachuca source based on its translucent green color. However, he didn't include in the site report whether the blade was analyzed to confirm the Pachuca origin. Odui is an ancestral Tewa village on the Parida Plateau near Los Alamos, New Mexico. Dating to 1325 to 1600, Odui has five multi-storey and Pueblo room blocks with an estimated combined total of 700 total rooms. A green obsidian prismatic blade was collected at the site, but it's unknown if it came from surface or subsurface contacts. National Park Service archaeologists likely collected it when they managed Odui from 1932 to 1963. Using EDX or spectrometry, Ferguson and Skinner determined the Odui blade is from the Pachuca source. Finally, Tumacacori National Historical Park in Southern Arizona is comprised of three separate Spanish mission units. A green obsidian prismatic blade was collected at Tumacacori, but park archaeologists know little about its context, though it was part of leftovers at the end of the 1986 inventory. In 2008, park archaeologists sent shackley the blade and 19 other obsidian artifacts from excavations due to determine the source. The blade is from Pachuca, but the other artifacts were produced from Arizona, New Mexico, and Sonoran sources. The trace elemental composition of the LA-54147 blade fragment was not reported, and it is unknown if the LA-80,000 blade fragment was analyzed. Also, I don't question Ferguson and Skinner's source assignment on the Odui blade, but I wanted all four obsidian artifacts analyzed by the same analyst. In 2018, shackley analyzed the three New Mexico artifacts using EDXR spectrometry at the Geoarchaeological XRF Laboratory in Albuquerque, New Mexico. A decade earlier, he analyzed the Tumacacori blade also using EDXRF at the University of California, Berkeley. Three subgroups of Pachuca obsidian exist, Pachuca I, Pachuca II, and Pachuca III, and the trace elemental composition of the New Mexico and Arizona blades compares well with laboratory reference samples of the Pachuca I source. The Pachuca source is 10 kilometers from the modern city of Pachuca, 100 kilometers northeast of Mexico City, and approximately 1900 linear kilometers south of Odui, making the Odui blade one of the longest traveled obsidian artifacts in the North American archeological record. Pachuca obsidian is a proclene glass and is elementally distinctive with generally high amounts of iron and zirconium. It is also phenotypically distinctive as the color varies from translucent bottle green to green black to a shimmering gold green and a brownish-red variety also occurs at the source. Pachuca obsidian played a significant role in the state-level economies of Teotihuacan, Tula, and Tenochtilan for millennia. So material and ideological evidence exists, demonstrating that people in the Southwest Northwest and Mesoamerica were undeniably and inextricably linked. People in the Southwest Northwest interacted with and acquired objects from Mesoamerica before the 900s. However, there is more evidence for interaction in trade after 900 CE because this was when the Southwest Northwest snapped together with Mesoamerica. Consequently, Mesoamerican obsidian should have entered the Southwest Northwest during this time. However, the lack of Mesoamerican obsidian at pre-Hispanic Southwest Northwest sites raises questions about the degree of interaction in trade and the extent of Mesoamerican influence on Southwest Northwest groups. For example, would green Pachuca blades have been valuable to Southwest Northwest elites if available? And why was obsidian not part of the suite of Mesoamerican material culture that moved north? Also, the limited presence of Pachuca obsidian after Spanish arrival in 1540 elicits questions. Who brought the Pachuca blades into New Mexico and Arizona? And why are there so few examples of blades? I now address these questions by using historical narratives from the 16th century and discussing how pre-Hispanic Southwest Northwest groups and the Mexican Indian allies organized their lithic technology. The raw material people use impacts how they organize their lithic technology because the material size, shape, and quality can structure the reduction strategy used and impacts the size of tool produced. Green Pachuca blades would have been valuable to political and religious elites in Southwest Northwest societies because lithic practitioners in the Southwest Northwest didn't use obsidian resources and lithic technology in the same manner as those in Mesoamerica. People in Mesoamerica rarely had limits on the size of tool they could manufacture since obsidian was available in mass volume and large boulder size. Consequently, they manufactured several types of tools from obsidian like prismatic blades, aeropoints, and ritual or stylized objects like scepters, ear spools, mirrors, and anthropomorphic eccentrics. Those in the Southwest Northwest, on the other hand, were not as fortunate when it came to the volume and sheer size of regional obsidian sources. Nodules from most sources, including Neal Creek from Western New Mexico and Celine, those nodules are approximately 10 centimeters in diameter or less, but however, they were still a valuable source of toolstone raw material. Southwest Northwest nappers often used the bipolar percussion method to obtain usable cutting edges from tools from small obsidian nodules, which hindered by-faced manufacture of larger tools. Pachuca blades would have likely been valuable to Southwest Northwest elites because Pachuca blades have a unique recognizable green color and because of its place of origin. Owning green Pachuca blades could have acted as pieces of places that would have connected Southwest Northwest elites to distant places in Mesoamerica. Along with the location of raw material sources as important places on the landscape, many groups valued the color of lithic materials. Green Pachuca blades would have likely been valuable because green or blue green colored objects were associated with water, fertility, and directional symbolism in Southwest Northwest and Mesoamerican societies. So if people, objects, and ideas circulated more freely throughout the Southwest Northwest and Mesoamerica after 900 CE, and if green Pachuca blades would have likely been valuable, then why was obsidian not part of the sweet and Mesoamerican material culture that moved north? One potential reason is that the Southwest Northwest already had sufficient obsidian to produce tools, and people there were only interested in acquiring copper bells, cacao, and scarlet macaws because those objects were not locally accessible. Also, the pochteca distributed green Pachuca blades using long distance trade networks, but Rainy Maguire proposes that the pochteca may not have traveled really far north into the Southwest North, or Southwest Northwest elites may not have wanted obsidian blades because they were the most common cutting implement in Mesoamerica, and cost so little to acquire that they were often discarded after one use. The LA54147 blade fragment is from context associated with the Coronado Expedition, and the LA-80,000 blade fragment derives from later context perhaps associated with the Pueblo Revolt approximately 140 years after Coronado around 1680. I suggest that these Pachuca artifacts were brought into New Mexico by Mexican Indians because there could have been as many as 2000 Mexican Indian allies accompanying the Coronado Expedition in 1540, as well as Mexican Indians lived in Santa Fe during the late 1600s at the Barrio de Analco community. Unfortunately, less is known about the other two artifacts from Odui and Tumacacore, although there is evidence the Spanish and their Mexican Indian allies visited those sites. It is important to discuss who the Mexican Indian allies were, because they most likely brought the four Pachuca blades into New Mexico and Arizona. The Coronado Expedition included approximately 350 people from several European countries in North Africa. However, the expedition would have hardly been possible without an estimated 1300 to 2000 Mexican Indian allies from Central and West Mexico. If as many as 2000 Mexican Indians entered the Southwest Northwest and likely brought obsidian blades for personal gear or weapons, why have archaeologists only found four blades and blade fragments? There are explanations as to the limited number and the answer stems from how the Mexican Indians organized their lithic technology, specifically their obsidian resources. The Mexican Indians were well-trained fierce warriors who used several weapons. The most infamous weapon was the obsidian edge wooden broadsword, also known as the Makana. This weapon was approximately 50 to 80 centimeters long and fitted with four to eight obsidian blades on both sides. Warriors used this weapon for close combat, and this weapon easily cuts muscular tissue and fractures bone, though experimental studies show this weapon's limits. Obsidian is so brittle that the blades inserted fracture after striking the opponent once, and the warriors had to replace the blades. If they brought the Makana into the Southwest Northwest, then they must have also brought additional finished blades and polyhedral cores to replenish their stock. Mesoamerican obsidian blades from post-1540 Southwest Northwest Contacts are so uncommon, potentially because of how blades were made. Few Mexican Indian allies on the Coronado expedition were probably trained in core blade technology, and Mesoamerican craft specialists used a wooden crutch to gain a mechanical advantage to detach long blades from polyhedral cores or pressure. The Mexican Indians would have needed to bring this device on the expedition to make additional blades, but there is no written evidence that they did. It is also quite possible then that they brought few obsidian edge weapons since they could not replace broken blades. Moreover, the Mexican Indian allies may not have brought a sufficient enough supply of chip stone raw materials from their homeland because they didn't expect to be on the expedition as long as they did. Once they ran out of their supply, they likely used the locally available lithic materials from the Southwest Northwest. They could have acquired obsidian from several sources as the expedition moved through Sonora, Arizona, and New Mexico. However, they couldn't have made prismatic blades due to the small size of obsidian nodules they encountered, though they could have made aeropoints and other tools. One way to assess the arguments made above would be to increase the sample size of source obsidian artifacts from sites with warfare between the Pueblo groups in the Southwest Northwest and the Spanish and their Mexican Indian allies. For example, at Piedras Mercados in central New Mexico, close to Albuquerque, archaeologists found dozens of Coronado-era crossbow bolt heads, metal artifacts, Mexican-style aeropoints and slingstones, and numerous obsidian flakes that could be debris from Aztec weapons. EDXRF spectrometry analysis of obsidian artifacts from that site demonstrates that the obsidian is all from New Mexico. It is beneficial to analyze additional obsidian artifacts from this time period, but studies already show that Mesoamerican obsidian is not present at other post-1540 sites in New Mexico and Arizona. In conclusion, despite the long geographic distance and vast disparities in sociopolitical scale, people in the Southwest Northwest and Mesoamerica knew each other, or at least knew of each other. At the same time, however, contact and trade were variable both regionally and through time. If Mesoamerica had more political and religious influence over the Southwest Northwest, utilitarian items like obsidian blades might have entered because they are low bulk goods that are easy to transport long distances. Until archaeologists find Mesoamerican obsidian from confirmed pre-Hispanic Southwest Northwest context, Pachuca obsidian is a time marker for 1540 and later in this region. Elites at Chaco Canyon and Casas Grandas likely emulated Mesoamerican elites by drinking cacao from special vessels and using scarlet macaw feathers on ritual paraphernalia. However, they did not need Mesoamerican obsidian because they had other more iconic symbols of Mesoamerican culture. Finally, this study contributes to the complicated and long distance relationship between the pre-Hispanic Southwest Northwest and Mesoamerica and the material culture of the Mexican Indian allies where an under-representing group in the archaeological and historical records. These four Pachuca artifacts represent the only known pieces of Mesoamerican obsidian in the Southwest Northwest, but many obsidian artifacts are in museum collections that have yet to be analyzed with XRF or Neutron Activation Analysis. Some obsidian artifacts may be from post-1540 sites and may also derive from Pachuca or other obsidian sources in Mesoamerica. So, I encourage researchers to continue to use geochemical methods to study the long distance movement of people, objects, and ideas across ancient North America. Thank you so much. Thank you, Sean. Alright, so anybody who has a question for Sean, I encourage you to contact him via email. He will be on the conference the next two days. He just couldn't make it this afternoon, so feel free to contact him on another day. Our next paper is Prehistoric Obsidian Procurement and Exchange in West Central Arizona by Michael Kellett. Hello, are we here? I don't see him in the list. Okay. Well, we can move on to our last paper for the day and see if Michael might return. I haven't heard from him. Alright, well, let's go ahead and do that. Hopefully, our last paper of the day is ready a little early. I'll introduce them and then make sure that that's okay. The last paper of the day before posters is Finding Obsidian Sources in Yellowstone National Park, Further Work by Andrea Veniello and Robert Tycott. Are either of you here? Yes, yes, I'm here. Alright, thank you for going a little out of order. I appreciate you going early. Thank you. No worries. Let me just try to see if I can share. Can you see? Yeah. Yes. Okay. So let's see if we can start and see what is going to happen. Alright, can you see it right? Any problem? Okay, it's good. Alright, thank you very much for giving me this opportunity to present again these materials. I have to say I worked that alone with Professor Tycott, obviously here in the lab in Florida, working on some of the analysis and statistics. I presented some of these materials already at the previous meeting, but I don't have really much more than preliminary observations done. I can tell you that this time I don't have new materials because obviously it was impossible to carve it around. It still is, but hopefully things will improve, but today I will present some more defined data. So this work that I've done in the National Park there in Yellowstone, and incredibly, although we know that there are many sources, and I guess everybody knows where Yellowstone National Park is. It's squeezed mostly in Wyoming with a slice of Montana and an even tinier slice of Idaho, and you can see that in this map just Maine and Ohio underlined because some materials from Yellowstone cover that far. My project really is about looking at the sources in the National Park and the immediate surroundings, and then look possibly at as many artifacts as I can and gather data from those already published and see how the distribution and procurement of obsidian in that area worked. So not really long distance routes, but the short area, which is with plenty of sources, some possibly not yet identified, and I went to that essentially with a non-destructive Pixar reference, you can imagine. Very quickly it's a super volcano, as probably all of you know, so plenty of sources, plenty of outcrops, and there is a particular area which is based on the caldera, and it is obsidian cliff, which are going to see in a moment. I show you just an idea, just taken from a recent book, the culture, not just obsidian, but the material culture of the tribes that lived and some still frequent that area, and you can see that, well, it's fairly complex and actually quite early. First traces are definitely paleo-Indian, also for the obsidian. It was very easy to collect, and you can see that plenty is actually scattered in temporary settlements and areas there. They were going there both to procure obsidian, but also to live seasonally in some areas, and so to use directly that obsidian locally. And very little has been done, I must say, to detect the movements within the park. This is another view, just to show you the variability of this material culture and the many differences that you can see in the periods. We will see some of the materials that I managed to access. I had the permission to check a lot of materials. Obviously, some have already been analyzed, so I didn't want to do those. Some were really put away in various deposits, and then there was the issue with geological sources, which brings me back to obsidian cliff, which you can see here. There was a survey that was done a few years ago. You can see here traced on a map the area that was surveyed, and it was actually a very good period because there had been a fire that had exposed many areas. Unfortunately, the materials picked up during that survey were mixed on the assumption that all obsidian from that area is from just obsidian cliff as a one source. And then they were analyzed, and there were doubts that something wasn't really quite working, but since there was confusion of which piece came from which particular site, nothing was made of it. You can see here that a large number of sites, mostly sites where mining was being done are exposed, but some were just places where obsidian was being worked, and a few actually are sites where obsidian was probably used. It's obviously a very nice place and even a hunting area. I'm just showing you a quick area of what I managed to go. It's a tiny slice of the thing, which is an enormous block of obsidian, high, tall, it's really large. It's gigantic, but probably it's not just the product of one single eruption from what I can see, and we will see in a second. The plans at this point would be to Goddard, even if it isn't after a fire, and try to zap a few sources, a few outcrops in different places, and see if it is just one monolithic block, or it is something, as we will see, more varied. This is just a picture when I was there in winter, and it's all obsidian, so just have fun looking at this gigantic piece of obsidian, and it is crumbling a little bit, but it's still massive, and you can see that on the top there is some vegetation, and there is also fauna, wild animals. We move very briefly before showing you some raw data to the materials that I analyzed. There are about 699 pieces of obsidian in terms of artifacts from sites, both on obsidian cliff and around it. I had just two pieces of geological sources, that is materials that were not artifacts. As I said, the plan was to return and do really the proper geological survey, which didn't work yet. You can see that there is an extreme variety of shapes and forms and uses, and probably some are from workshops, some are definitely from settlements, some are from more complex sites, which were reused. You can see that I tried to track also some of the known obsidian evidence. I'm not doing a typological study, but at least I hope one day to be able to describe some of the stuff. Not all has been described, not all has been published. You can see here in this case, that is what looks like a small core as well. I tried to analyze as much as I could, and there is much more undoubtedly to be done, and also previous publications and also reports that the National Park Commission that should be integrated, and it will take some time. I move then to the first graph, that is probably what you were waiting for. This is actually a slide that I take from my past presentation, where I was suggesting this is a simple principal component. You can see that there is a scatter of pieces, and then what could have been two main groups in representing obsidian cliff. That was my preliminary analysis of what I could do, just trying to see if I could distinguish particularly the outliers. I wasn't particularly interested in obsidian cliff yet. We move to a more complex principal component, where I started doing some more work comparing different elements. I also included and excluded iron in this case. I think that it is slightly included, but obviously these big dots represent a number of materials. Don't think that 671 samples are clearly visible. You have these big dots that hide in reality generally smaller groups, but you can see obsidian cliff. You can see the big group there that we had seen in the previous slide that is now split in two, if not three. It is quite interesting because again, everybody assumes that obsidian cliff is a single monolithic piece. Nothing has been done around it. Because of this variance that you can see chemical variance, it is causing some problems in assigning the artifacts to actually one source or the other, because obsidian cliff has values that vary a lot. I hope with this research, once I can do the geological survey and gather some geological samples to be able to distinguish it better. For now, you can see that things look promising. There is more variability, more variance than supposed, and I hope also to be able to get some contextual data from some of the sites and so understand, for example, when some sites were used, not in terms of broad period, but hopefully also of a seasonality that would be useful, and particularly associating together sites that were connected to production and sites that were instead linked to some kind of consumption. As I said, obsidian cliff is essentially a quarry, but also it's a hunting ground and there is all the area surrounding it that is still beautiful, and it's still used by some Native American communities, for example, for hunting bison, and so it's still very active. I show you from the main group, I still at this point created like one, just to show some variability there. You can see some averages, minimum, maximum, and this just a tiny slice of the table, it would continue as you can imagine. It's just to show you a little bit what kind of data I have. I don't have a data, because obviously you should scroll, I can share eventually the headings, but it's not really important. The first column, as you can imagine, is just the basic elements, iron, and then the trace elements, and others are simply columns kind of doing analysis of specific elements. We can move to a smaller group, and here I don't have really averages or other things, because as I said, I'm still working to try to decide, I barely decided that I probably want to split, at least tentatively obsidian cliff, and these smaller groups that we have seen as a single dot, so there's just one representation, basically, what one dot would have been, and you can see here it's a group of a dozen essentially artifacts. So don't assume that there are like 50 pieces from obsidian cliff and a scatter of a few. We don't have for some really any kind of comparison, even in the literature. So some of these smaller groups, and I can go very briefly back possibly to this, some of these outliers can be recognized or attributed to some source within the park or just outside or even hideout, but some are still not quite as clear in the sense that they are in between possibly, and that is because nobody has done a proper geological survey of the park, and I would like with the knowledge of the people that are really to go and do and zap as many outcrops that they know as possible. And so let's really wrap up a little bit this presentation. I'm really sorry that I can show as new thing only really this idea of obsidian cliff being split and talk a little bit more about the plans. I was hoping that at least some of the geological survey would have been completed, and I could actually confirm this idea that obsidian cliff is not just one piece of obsidian that is homogeneous. I can't do that yet. We all know why. But it is quite intriguing, and it will be important also to assign the materials that are dug in different areas of the park and just outside the small number of outliers. I have identified Cougar Creek as one of the major sources outside obsidian cliff that is known in the literature, but I have to tell you that again I couldn't really get samples from there, and there is also geological samples, and there is also the issue that there are more outcrops pretty much everywhere in the park. And I'm finishing really with the last bit saying that obsidian cliff as you know is an important even national monument. It's not easy to access it. It will require a special permission, and I hope to do so as quickly as possible. I'm really concerned particularly with unknown or uncertain sources. Just looking and re-looking at the data show that there are some at least. We don't have any patterns at this point that is based on chronology or type of use. Those will also have to come, and that's pretty much what I hope to tell you next time. I can't say much more other than really thank particularly the National Park Service for their help and support, and hopefully I will be back telling you more. Thank you all. Thank you Andrea. We have some questions. Yes, I think I can stop this here. Is this part of a master's or PhD program research? No, I'm a research fellow, so no. Nothing to do with that. It's my own program basically. I hope to bring some students there. I was hoping to do that, but it has been really hard. And as I said, it's not a place you can just go data on holiday. You need a special permission to access the National Monument of Obsidian Cliff. And so it takes six months to get that permission. And when I was basically planning it in the fall of 2019, then I said, well, I will probably send it out for early spring. And so early fall of 2020, I will go there because obviously it's subject to a lot of snow. So you can go there in winter. And during summer, the National Park is busy with the tourists. So you have basically something like a month, two weeks in between and two weeks in between spring and fall when you can do this research. And I just didn't manage to do it. But it's just a petty project that I wanted to expand with students and bring them there and show them around a little bit Yellowstone that I love. But yes, it's a pity. It's a project pending. Well, I'm sure many of us here can sympathize with the pending project, nature of things. A lot of us anxious to get out into the field. Oh, yes. Did Michael Kellett come on? No, he or so. Well, that ends a little early for us before our poster sessions happen. Those can be started at any time. People are inclined to poster in one of the assigned breakout room. Just a reminder that you can move freely about any of those rooms. The presenter will share their screen just like what's been happening today with the PowerPoints. It'll just be a single slide. You can engage with them using audio or the chat function. Keep in mind that if you post a chat to everyone, those questions and comments will be archived along with the video and we can revisit those. If you post them privately to the author or authors, those will not be archived. And also you're free to use the links that Nico just provided in the chat window to comment now if you like or comment later. I know many of you, it's reaching the middle of the night, early AMs for people. So I appreciate all of you staying on as late as you are and out the day. I'm also using this opportunity to kind of have a little announcements. So keep in mind we'll start the meeting tomorrow at 8.30 so people have time to log in. Also too, we neglected to mention this morning that the International Association for Obsidian Studies will have their annual meeting Sunday at the lunch hour in its own breakout room if you want to attend that meeting. I know many of you are members of that now or returning members and we want to share our appreciation then. So I'll just leave this window here and we'll just wait for the posters to begin. Feel free to ask any questions of any prior presentations as we finish the day. Thank you.