 Good evening everyone, and welcome to a special summer lecture. This year the society was unable to put on a science festival lecture as we normally do, and indeed the entire Glasgow Science Festival was cancelled due to the pandemic. But today we've got a lecture that will hopefully fill some of that science gap in our programme, and maybe with some discovery oriented diversions along the way. It's not currently possible for us to assemble on mass in a lecture theatre, and we expect this situation to continue at least until the end of the year. This is the first time society's attempt did a virtual lecture, so do please forgive any gremlins that may appear. Before the questions of course, we have a lecture, and our speaker tonight is Mr David Webster. He's an accomplished speaker who's recently presented to the Geological Society of Glasgow using Zoom, so hopefully knows what he's doing. David Webster has a degree in geology from Oxford University and MSc from Stockholm, and he's worked for many years in the oil industry. He's now actively retired and has built a house on Islay, and is co-author of a guide to the geology of Islay. Please feel free to pour yourself a wee drum if you favour Islay whiskey while you enjoy tonight's lecture, as David takes us on a guided excursion around the geology of Islay. So David, if I could please ask you to share your screen and un-mutual microphone, the floor is all of yours. Can everyone see my screen? Yes, I can. OK, right. Well, welcome to Islay. We're going to do a quick tour of Islay, and we're going to throw a bit of history and archaeology into the mix just to sort of show how geology relates to all these other disciplines, and we'll have a bit of whiskey as well. There's a story link between geology and whiskey which I've really enjoyed exploring and researching, and I'll have a look at that as we go along the... So I think everybody knows where Islay is. Southern Hebrides, nearest island of Scotland, Ireland. You can see Ireland quite well from Islay. You get to it on the ferry from Kennecraeg, and you can actually get there from Oben as well. So, yes, actually south of Glasgow, believe it or not. People think it's north, but it's not. It's actually south. So we're going to tour a wee bit of Islay. You have to start with the geological map. Everyone likes geological maps because they're beautifully coloured. Geologists always talk about rocks in age order. So when you see a column at the side of a geological map, hopefully it's an age order oldest at the bottom. We always start our stories at the beginning, and off we go looking at all the different rock colours in the geology of Islay. The oldest rocks in Islay are in the west, and the youngest rocks are in the southeast, and it pretty much mirrors Scotland and pretty much mirrors the UK. The oldest rocks in the UK are in Paris and Lewis, and the youngest rocks are in London. Ireland is like a miniature version of that. So it's oldest over here and the youngest over here. But it's all relative because these rocks here, the oldest rocks are about, and I'll talk a bit more about them in a minute, are about 1.8 billion years. Now, the earth is 4.7 billion years. So these are quite old, half the age of the earth, bit less than half the age of the earth, and the rest of Islay is round about 600 million years, between 800 and 600. So we're talking about the Precambrian. Those of you who understand a bit about the periods of the earth, this is Precambrian before the major burst of life at the Cambrian. So these are all older rocks than 540, which is the beginning of the Cambrian. These are late Precambrian, and these are sort of quite early in the Precambrian. So we're looking at some rocks here, and I'm going to move on to the next slide, because I wanted to show you the old maps. These are the old sort of late Victorian surveyors, basically the whole team of the British Geological Survey, surveyed the whole of British Isles, and including a lot of Scotland, obviously, at the time. And these guys are just well known. These are our heroes, Charles Clough, Ben Peach, and they did a very, with all their colleagues in the British Geological Survey, produced this wonderful map in the very early part of the 20th century, and it is still a good map. They were observational scientists. They observed the natural landscapes. They were interested in describing things, and they just drew a beautiful map of Islay and the rest of Scotland. You can see the detail in this when you get into it. It's beautiful. This is a nice map. I want to mention this guy as well. This guy, Baddysby Bailey, is famous for... He did a sort of revised version of the map and brought it up to date for 1916. He was an interesting character. This guy, Mapdyla, in short, he thought that long trousers would get too wet. He cut off the toes of his shoes so that he wouldn't get wet feet. He tied everything to his body and his jacket with string, and Etty's lunch before he left his accommodation so that he wouldn't have to carry it. He did a fantastic resurvey of the map, but it didn't change it vastly, but he got the structural details of the geology dead on. This map and his work still stand stead today. We have a great regard for Baddysby Bailey's work in the very early part of the 20th century. Time. We have to talk geological time. I did mention about 1.8 billion years ago, and we're going to talk about the early rocks of what you see on Isla, round about 1.8 billion years. Then there's a big gap. We call it the billion-year gap before we actually get a lot of sedimentation that we're going to see that's around about the 600, 700, 800 million year, the late Precambrian, which is most of Isla. Then lots of we things happened right through the rest of the geological time up to the present sort of ice age that we're still in at the moment. We're going to focus a bit on the Rins complex. At the bottom of the column here, we're going to have a look at this stuff here and have a quick look at the end about some of the stuff that happened later on in geological time. Three key periods of time we're going to investigate in three key areas of Isla. Here's a Google Earth map of Isla. We're going to head off to Brachladig, which is where I've got my house. I live over just here. This is a bit I know quite well. This is the Rins Peninsula. People who know Isla would know this is the Rins. It's almost an island. There's a sort of neck of low land here. This bit of the western side of Isla is the Rins. Rest of it is the mainland bit. The towns of Beaumaud, Port Ellen, and here in Port Asgig over here. Brachladig is a wee village dominated by distillery. My house is up on the hill behind there. It's a very pleasant place to start your geological tour of Isla by driving along here, the wee shop, and you can stop here and look at rocks. I thought I'd gone out of the rock. Anyway, so we've moved on to Port Nehaven. I've got a picture of a rock in a minute. It's coming up. There it is. Yes, sorry. This should have come after the Brachladig slide because at Brachladig and at Port Nehaven you see two key rocks in the Rins complex. A pink rock and a sort of greeny black rock. These are the common rocks that we see on Isla in this part of the Rins complex. If you go to any beach, you will find these red pebbles and these greenish sort of blackish pebbles and they belong to these two rocks. 70% of this Rins complex is made of this and it's a nice. It's a nice and it's a sort of once was a granite, a quartz por granite called a cyanite, and it's got this sort of crude banding in it. It's been metamorphosed and changed, but it was originally anignous molten rock called a cyanite, and it's now being a nice, a scientific nice. I'll explain a little more about that in a minute. The other rock is a greenish rock there here. It used to be a basalt or a dollarite, but it's now been metamorphosed and it's now a meta dollarite or a meta basite. So you get these red rocks, pinky red rocks and these sort of greeny black rocks and I like to sort of think of them as sort of like green apples and red apples, but they're very, very common, these pebbles and this is the predominant rocks in the Ryns complex are these two rock types. We're going to move on. I meant to show you something important to haven, but I've just in terms of time, I'm going to just move on to Losswick Bay where this Ryns complex is well exposed. And this is Losswick Bay. It's one of my favourite places on Islay. It's a beautiful bay on the west coast and we're going to have a quick look at some of the rocks you see down on the south side of the bay. And it's called the Ryns complex for a very good reason because these rocks are complicated. There are lots of rock types. When I said it was simple and there was just a pink one and a sort of greeny black one. Well, there's the greeny black one and that's the greeny black one. There's the pink one, but there's a black one over here, a different black one, a different black one here. There's a fold in here. There's all sorts of other pinky rocks here, black rocks here. And it's a bit of a mess. It's not nicely layered. It's not structured very, very difficult to sort of work out what's going on. And these are a whole bunch of rocks that have been, well, once all igneous rocks, they're all molten rocks at one stage in their lives and they've been chewed up and messed about and recrystallised and partially melted and all turned into different things. So they're igneous rocks that have been metamorphosed. So we call them meta igneous rocks. And where did they form? Well, this is a classic sort of diagram that I drew. I stuck in the book, which was to do just a couple of years ago when I stuck in the book, which was to do just to sort of illustrate the main principles of plate tectonics with mid-ocean ridges creating oceanic crust, which is being destroyed in trenches. The wet cold slab going down causes partial melting of the Earth's mantle. Magma rises up and volcanoes appear in volcanic arcs or on continental crust, they'll appear like the Andes or Japan. So I believe that the Rins complex was formed at this sort of area here in the Earth's crust, probably 30 or 40 kilometres down in the Earth's crust underneath an active volcanic arc, which was forming at that time. So 1.8 billion years ago, Eila, the bits of Eila we see today were formed in a volcanic arc formed on the edge of a continent. This continent 1.8 billion years ago was called Columbia. Some of the literature calls it Nuna. It seems to be interchangeable depending on which field and school you belong to. Here's a map of Columbia, and it's got the existing bits of Scotland. This is NS, this is Northern Scotland. So Northern Scotland existed. This is Northern Highlands of Scotland and Lewis and Harris. They existed 1.8 billion years ago and were a continent. This is the Baltic Shield. This is the core of the Baltic area. This is Northern Rockall. This is Greenland. This was at the edge of the continent. Imagine this is almost like the edge of Asia and this is Japan. There's a volcanic arc sitting at Eila's the Star. These are volcanoes. This brings black dots here. This is a trench here, an oceanic trench destroying the oceanic crust. This was where the Rins rocks were formed 1.8 billion years ago. This is a malin arc, but the rocks stretch all the way from Greenland to Sweden. About 1.7 billion years ago, i.e. not long after, but 100 million years later, that arc had crashed into Columbia. We call it an accretion complex because it's added on to Columbia. Continents grow through plate tectonics. They grow in a creek, so we're getting more and more continental crust growing all the time as plate tectonics continues to evolve, the Earth's crust, and create more less dense continental crust out of the oceanic crust. We get these things happening all the time. Eila's here, and this is the southern part of Scotland here. This is the Grampian terrain here, which has been moved by strike-slip faulting and joined up with this subsequently, but at that time, it would have been well south of northern Scotland. The southern part of Rockwell, the drilling and the dredging samples on Rockwell show that there's the same rocks. Southern Greenland has the same rocks, and southern Sweden and Norway have the same rocks. So, this whole band of rock that we see on Eila actually has a lot of affinities with Greenland Rockhall and Sweden. And we think his Eila here, right in the middle of this belt of rock here, the Dalradian rocks, which we're going to see in a minute, and it's the basement. Geologists often call it the basement. It's the oldest rocks you see that all the younger rocks are sitting on. And the basement underneath the hole of Northern Ireland, the hole of Donny Gawll, northern Mayo, right up through Eila, Argyll, right through the Grampians, right through the Cairngorms, right up to Peterhead. If you drilled a hole anywhere in this area, down deep enough, you would hit the Rins complex. It's underneath all of this area. Different rocks over here, the Great Glen Fault and the Highland Boundary Fault are major terrain boundaries. They're big geological boundaries between different chunks of rock. That accreted arc went all the way along here, and then you could follow it out to rock all that way in Greenland, and you could follow it this way into Sweden. So this is a little window. It's the only exposure we have. We've got a little tiny rock outcrop here, just off Donny Gawll, in Ishtrul, and pretty much that's it. There's a few bits over here, but they're a bit changed over here in Mayo. But basically, we don't see these rocks, but only on Eila. So it's a unique opportunity to see some really old rocks and the flooring at the floor of part of Scotland. Before I leave here, my first whiskey exploit here, this is a whiskey story, because this is one of the few bottles of whiskey I know of, perhaps the only one there is, with a geological map on it. Brooklady produced this whiskey in 2007 from a 1980 barrel, and they put this geological map on it. The reason, and they called this particular expression Eila, because Eila is a place in Peru, and they invited the mayor of Eila in Peru to come to Brooklady to taste this whiskey and meet him here, because at that time, they thought that the rocks of Eila, the Ryns complex, was very similar to rocks in Eila in Peru. In fact, here is a picture of Eila in Peru. It's on the coast. It has pink rocks and dark rocks, very similar rocks. This is their badge. This is where it is in Peru. The mayor of Eila came to Eila to sample his eponymous whiskey. Here's the map that's on the bottle. It basically tried to illustrate the fact that at that time, they thought that northern Scotland and Peru, or that part of Gondwana in South America, were joined up, and Baltica was over here. We now believe that to be erroneous, we are facing Baltica at the time, because the geology is much more like this. Although there are rocks of the same age as the Ryns in Peru, they're not actually joined up. There's a spring of water that comes out of these rocks that still are used to dilute their whiskey from cast strength to bottling strength. It comes bubbling out of the rocks on the Ryns complex. The 1.8 billion-year-old rock is producing a very weird spring that the local farmer is pumping out, which supplies all the water at Brookladde for their cutting water for the whiskey from cast strength, the bottling strength, and it's also all the water. This special water is all the water used, and the bottom is gin, those of you who've sampled their wonderful gin. We've sampled this water geologically or chemically, and we've realised this water, although it's quite soft, it's still below pH of 7, it's under pH of 6. It's a little bit higher than the rest of the isle waters, which are very soft, a little bit harder than Glasgow tap water in terms of its pH, but it's got a very high silica content, and this is a strange water to get, because all the river water, all the burrens, everything in there comes off the rain, and it'll be just like this. These waters here, the waters you get in the main distilleries. Bryglady's own bottling process water is very soft and contains quite low silica and low alkalis as well, but the Octomor spring is unusual. We reckon that it's because it's lies on a fault pattern, and the faults cutting right through this rinse complex, and I think there's a picture of the faults there. All these faults seem to focus on this where this strange spring is. The spring is sort of that previous picture, or earlier picture, it was next to the burren, and the burren's got pretty much rainwater in it, with low silica, and the spring has the high silica in it, and it's probably because it's percolating through all these old crystalline rocks, which don't have a lot of carbonate in them, but they have a lot of silica in them. So there's a geological reason why this water is different. It's probably a very old water, and Bryglady make a nice marketing ploy out of this, and it makes nice whiskey. So it's a good geological story for your whiskey. This just summarises the geology of that area, because there's the band of rocks from Greenland into Baltico where Eilor is, and we think the Peru rocks are over here somewhere, quite a long way away at the time. 800 million years ago, we reckon that Amazonia was over here, and the beginning of a split of this ancient continent called Rodinio, and we'll talk a little bit more about in a minute, but this is the rocks that line up, we think now, not the Peruvian rocks, but it's a good story, and the water from the spring is very different geologically to the rest of Eilor's water. So we've had a look at this. This is the Ryns complex, just sort of put it in the perspective. These are the nicest and the metric basite rocks, the pink and the green rocks here, and they're overlaid, by a whole series of rocks belonging to what's called the Dalradian, which is a whole group of rocks, maybe 20 or so kilometres thick in total, deposited over a 200 million-year time frame on the edge of this Rodinio continent that was splitting up. So Rodinio was the supercontinent that existed 1,000 million years ago. Remember, Columbia was the supercontinent that existed 2 billion years ago. We've got this new supercontinent Rodinio, which is breaking up, and a whole load of rocks are formed on the edge of it, which is called the Dalradian, and the Dalradian rocks do cover pretty much Scotland from Eilor up to Peterhead, and they sit on top of this Ryns complex, which, as I've just said, only exists on Eilor as exposure, but it's underneath everything, and all these sort of rocks exist along strike in Scotland. So we're going to have a quick look at this one here, and then we'll move up to look at these and these at the top. So I just wanted to take you to Kilkearn Bay. We were on at Losswick Bay earlier, and Brookladiw was over here, and Port Charlotte was here, and that spring was here, and we're just on the coast on the far west of Eilor at Kilkearn Bay, and here's a sort of badly-made panorama of Kilkearn Bay, and we've got here what we're called metasediments. So these are metasandstones that were once sand, and then it became sandstone, to become quartzites and metasandstones, and then we've got mudstones in here, which are slates, and then we've got more sandstones over here. And there, this is the pink rock here. It's a bit dirty, and when you look at it, you can't see that, but when you get there, it's pink, this is the pink rock, this is 2 billion years old, 1.8 billion years old pink nice, and over here is 800 million year old quartzite. So there's a billion years of geology missing, or time missing in this billion year gap, and this is Allister from Stockholm, standing straddling the billion year gap, and you can walk on a low tide, you can walk into this, and sort of put your hands either side of the gap, where there's a billion years of Earth's history sort of missing between the, this is quite called the Kilkearn Shear Zone. In fact, your picture was over here. You can see that all on the Earth's satellite photograph here, these rocks here are the nicest, and these rocks here with a lot more structure and foliate lineation here are the metasand stones of the Colonsy Group, and that picture was taken in here, and the shear zone is offset by this fold here, but the Kilkearn Shear Zone is a very prominent feature separating the 2 billion or the 1.8 billion year old rocks of the nice here from the metasediments on this side, and that line is quite prominent. It's a lovely walk down the coast here and all these little tidal inlets and tidal bays that the shear zone runs through here, because it's a shear zone, it erodes out from the harder rocks of the quartzites here and the pink nices here, there's a sort of zone of erosion along the coast here, and it's a lovely place to go. Further north, these rocks turn into, slightly above these rocks of the Kilkearn Bay, we get what we call the turbodytes. These are Colonsy Group turbodytes where they're deposited in very deep water, with finding up cycles of sand to mud and sand to mud deposited probably during earthquake times. So there's a whole lovely succession of rocks from Kilkearn to Saligo, which form the Colonsy Group, which go to Colonsy as well, and they're all around about 800 million years ago, and they're the first deposits formed as rodinia broke up. So that's the map I showed you earlier. There's Isla in this sort of growing split. It is starting a bit like the Red Sea today. The Red Sea is splitting Arabia from Africa and breaking up the African Asian continent. This split started to break up the rodinia supercontinent, and this happened and got bigger and bigger as the Dalradian sequence was deposited. We got a small rift and it got a little wider rift and eventually became an ocean basin that separated Laurentia, which is sort of basically North America, Scotland, Greenland, from Baltica. So we finished over here. Just checking how we're doing for time. Yeah, we're okay. Yep. So we've been here. We've been here. We've been here. We've looked at the Colonsy Group, which is the green stuff. We've looked at the Rins Complex, which is that. I'm now going to take you over to the sort of central part of Isla to a place called Baligrant here, and we're going to look at some deposits of rocks in this area and up in here. And at the end of the talk, we're going to end up down in here. But we're going to start at Baligrant, which is right in the middle of the map here. And the rocks we're going to look at are rocks in the middle of the succession, around about 700 million years old. Basically, we're going to look at these three types of rock here. The Lossid limestone, the Poesgig teal, and the Bonnarhaven dolomite. These limestones are like a sandwich of rocks that are limestone carbonate-type rocks. Dolomite is a magnesium-calcium carbonate, whereas limestone is a calcium carbonate. And it's got this thing called the Poesgig tealite in the middle, which is a glacial deposit. So we've got warm water limestones sandwiching a cold glacial deposit. And this is the alleged snowball earth signature on Isla. So we'll have a quick look at this. Baligrant is a lovely little place. It means Baligraenor, which is graenor. I can't get the Gaelic right, but it means it was the city town of the grain originally. Baligrant is in the middle of Isla, and it was well known for its fields of wheat and barley and oats in the past. And you can see that when you look at the Google Earth maps, you can actually see this is the fertile strip of Isla. All these green blobs here are fields that are fertile because there's limestone in it. That's the key to the fertility of Isla. And it's why it became an important part. And you've got to fin laggan to the Lord of the Isles historical centre here. Isla was important because it was the production of grain. It did have fertile land, relatively well sheltered. And Baligrant was at the core of this area. And so it was a lot of these fields grew grain. In latter years, it was turned to dairy. Dairy is gone now, it's sheep and cattle. And in the last few years, it's returned to grain. Not because we want oats and barley, we want oats for porridge, we want barley for whisky. And these fields, you can see these plowed fields now, have turned from sheep fields to barley fields. And there's a lot of barley now grown in the central strip of Isla for whisky. But what Baligrant was famous for in the sort of, from the sort of 14th century on, was lead mining. At Mulreish, just underneath on the Isle, this is the perhaps the Dura in the background. There's some big lead mines that we're operating in the 17th, 18th centuries. They were looking for galina, lead sulphide. There's this cubic sort of metallic sort of ore. There's quite a lot of it there. It was all hand dug mainly. There was a smelter at Podaskag in the 17th, 18th century here. And these are sort of old engravings of that. So it was smelted on the island and exported. The lead was exported. And there was a byproduct of the lead mining with silver. And Baligrant at the quarry there now, there's the Gartnes mine that was famous for the sort of byproduct. It was actually more mined for the silver in it than the gold. And this is a goblet that's actually in the Kelvin Grove collection. And it's a little label Eila silver. And it's made about 1780. So there's silver on Eila. Or there has been. The mines that were malicious still evoked. You can go and have a pot around these things. You're into art, industrial archaeology. There's a washing poo pond. There's big drainage addicts. There's shafts and ladder shafts. And a lot of miners were imported or immigrated. Immigrants came from Wales and from Cornwall to work the mines. And there still are Edward's and Griffiths on the island descendants of these original. Some of these Welsh miners that came helped exploit the lead came and went. It was a movement bust economy. And there were sort of all sorts of boom times and poor and bad times. And I've managed to pull together from all the records and the sort of amount of lead that was produced in a sort of each 25 year period from historical record. Now there's not much before the sort of 16th century, but there were certainly, you could see, there were periods in the history records when mining investments were made and then it all tailed off and more investments were made and it tailed off. In fact, there was very little, very little, no more lead was mined after about 1880 on Eila. The geologic connection is that because there was lots of talk in the historical record about whether the Vikings lay back before this and even in this part of the before historical records, whether there have been any lead mining prior to the 16th century. And an enterprising PhD student in Edinburgh did some work on the sediments in the various locks that these mines drained into to try and see whether there was any sign of lead pollution and integrate the lead record in the peat cores to the pollen records and to other dating things. So we can actually try and date any geochemical anomalies in the record. And this is what you found in the various locks and tried to match the geochemical anomalies with the mining records. And there's a crude connection here, but the Loch Llock seems to have evidence of mining that's before any historical record around about the beginning of the 15th century. So there's sort of a nice tie-in between archaeological history of industrial archaeology history and sort of modern geological techniques to try and tie the whole story together. They didn't find anything at all, so it was any earlier than this. So we're still not convinced that the Vikings' mine led on Isla. We know the Vikings are on Isla, but every settlement township has got a Viking name, but we don't think they were into the lead. Nowadays, Bally Grant has a huge quarry. The limestone is well used on Isla for roadstone. Every track on Isla has a Bally Grant limestone, and it's quite a big operation from Dunlosset Estate to quarry this limestone out in Bally Grant. And one of the mines, the silver mine, actually cuts right through here, so I've had a scrap around in here trying to find some silver, but I haven't found any yet. Anyway, above the Bally Grant limestone, there's a loss at limestone, and it's got these things called stromatolites, which are sort of domal mounds of algal material. So this is life in probably a fairly warm sea happening in and around 700 million years ago. And again, the green fields are where the limestone is, and then there's sort of the heathery hills in the distance are some of the quartzites, and where they're much poorer soils. So the farming is all done on the limestone. On the limestone outcrop, and it looks like this when you suddenly see it exposed as sort of a grey limestone, and it has these stromatolite domes in them. It's just about 700 million years ago. And it's overlained by the Port Asgig Tillite. Now, I could spend hours talking about the Port Asgig Tillite. In fact, there was one of my co-researchers here this morning was talking about the Port Asgig Tillite. It's a big story to be had, but I'm going to just skip over it very quickly. Port Asgig Tillite is a glacial deposit formed by the melting of ice, and it's a dump of all the stuff from clay to boulders that are deposited when the ice melted. And we believe there's about nearly a kilometre of this thickness of rock on island, which is quite unusual, and it was all deposited by melting ice. So each, there were glacial cycles that would bring this mud and stuff down and the ice would melt, and then we'd work by the sea and then another glacial pulse would come, and we'd see lots and lots of glacial pulses in the Port Asgig Tillite. It was one of the first deposits ever recognised in the world that it was a rock, a fossil rock, an old rock that must have represented a glaciation that happened a long time ago. These guys didn't know how long ago it was. Modern dating hadn't happened then, but we now know this to be around just about 700 million years old, and we believe that rocks of this age around the world are typified by glacial deposits. So we've got glacial deposits of 700 million years old just about on every continent, and all the other evidence points to the fact that these were at sea level and at low latitudes. So we're talking about something very strange going on. This was low-latitude sea level glaciation. Now we have low-latitude glaciation today, or certainly ice fields on Mount Kenya, Kilimanjaro on the equator, but they're at 5,000 metres. This is at sea level. If we had ice today at sea level on the equator, we would be pretty worried about the climate and how the climate had changed. So this was what was happening. These were ice fields extending to sea level on the equator or near the equator. And it's obviously been termed Snowball Earth. Probably many of you have heard of this term. When we believe, it's believed that the Earth completely froze over 700 million years ago, and the deposits of the Port Asking collect deposits in the world to be recognised, to be part of this phenomenon. Now how the Earth got into it and how the Earth got out of it is a subject for another lecture, but nevertheless, Islay is a key point in the story of Snowball Earth. I've just seen another map, a different map, a different author of Rudinia at about that time. And I think I'm going to click again. Scotland will appear. Yes, there we are. Scotland is still on the edge of this rift. It hasn't turned into an ocean yet. We're still in this rift. There's Laurentia, or that's North America, Northern North America. There's Baltica, there's Amazonia, and it's Peru, but it's still over here. And we've got this ice field. All these green dots are all ice deposits around the world on every continent that's got them. And we believe at that time, all the continents of the world were clustered in a single supercontinent Rudinia, which was pretty much straddling the equator, which meant it does change the ocean circulation patterns quite a lot. And maybe this is part of the reason why Snowball Earth happened, because it was an accumulation of a supercontinent straddling the equator. I mean, it's quite possible that was ice over here, but no ice at the poles. We don't really know, but that's one of the things. And I've shown this thing called the flip, which is the Franklin large igneous province. And it's possible that the combination of this continent over the equator at that time, along with a massive outpouring of volcanic rocks, was actually enough, the weathering of these rocks was enough to draw down the CO2 to cause massive cooling. And eventually, the amount of volcanic activity that then would then increase the CO2 and cause global warming again. So it may be a combination of this continental configuration and this igneous province being weathered, silica weathering, and then volcanic gases later on bring us out of Snowball Earth. So a lot of research is going on at the moment to this. Papers every day get published on it. I've just skated over it very quickly, but it's a nice story and there's a lot of interest in this. I just want to take you up to the north of Eilir very quickly, because I mentioned the Poeski Tillite and the Losset limestone, the Bally Grant, which is down in here. These are the limestones that underlie the sandwich of the Tillite. And I mentioned there was one on top. This is called the Bonahavn Dolomite, which is sometimes called the cap carbonate. A lot of these Tillites and glacial deposits in the pre-cabin around the world have a starter limestone. Then there's a Tillite geolod diamictite glacial deposits. And then it's followed by Dolomitic rocks or carbonate rocks afterwards. It's a lovely place to go. This is the north coast of Eilir. This is Bailan Dodaris, beautiful bay, beautiful raised beaches, beautiful cliff scenery. In fact, these cliffs, these caves here were inhabited and lived in, not just as shieldings. I mean, we're all lived in all year round by various farmers. These little fertile raised beaches were farmed. A lot of goats live in here now, but you could live in there still. They're big caves. They're raised up. They were formed by the sea 9, 10,000 years ago, but now the land has risen, the sea has dropped, and they're now raised caves. But what we come to see on the north coast is the Dolomite, and it's these huge mounds of algal material. I remember I showed you one earlier underneath the Tillite. But these are huge. There's one of the researchers Ian Fairchild standing there. You see how big these things are. These are a couple of metres high and four or five metres across. These are huge, great big mounds of algal material growing in the shallow warm seas after the glaciation had finished. They grew because nothing else ate them. There were no grazing gastropods. There were no grazing things. The algal domes were life as we knew it at that time. Sometimes they're relatively small, little isolated bumps, and this bed here extends all the way around this rock outcrop here, and it's draped by this layer of sand, which we think is a storm layer, which killed off these domes. These domes were growing quite nicely for probably a long time. It grew quite a long amount of growth here. Something was a storm, a massive storm, that deposited a foot or two of sediment over the top and drowned a whole lot of them. These stromatolites have been in existence on the earth probably almost three billion years ago, so these are only quite, these are only 650 million years old, but you can get them today in Sharpe Bay, Australia. They exist in the hypersaline lagoons where the gastropods don't like them, don't like to eat them, but these are similar, so nothing has changed really. The present is the key to the past here. The shark-based stromatolites are very similar to the ones we see in Islay 700 million years ago. Just to mention another whisky connection here, the Bunaharvan dolomite has a spring on it, and Bunaharvan distillery take water from this spring and use it to make whisky. You can see from my chemical analysis here, we've had a look at this water here. It's quite high in magnesium and it's quite a high pH, and it's one of the few distilleries on Islay that doesn't have soft water, it has hard water. Arguably it makes a slightly different whisky. There is a lot of thought as to how much this hardness changes the fermentation process. So it's not about distillation and chemicals coming through the distillation because your carbonates are insoluble, but they might affect and they will affect the fermentation. In fact, soft water is liked for whisky fermentation because it makes a faster fermentation. This is slower and can reduce some higher alcohols and a load of esters as well. Water is important to the whisky industry, and getting it right is what you do. But Bunaharvan is slightly different to the rest of them because of its hardness of water, because it comes off this dolomite where the stromatolites are. I'm going to take you down to the south of Islay. We're still doing it all right for time. There's three distilleries down here as well. This is Lathroig, this is Lagavulin, this is Ardbeg, and the geology of the south coast of Islay is dominated by these green stripes here. These are metahygnus rocks. They were intruded as horizontal sheets of rock in the developing part of what became the Yapitas Ocean. This rift that Rodinia created in Rodinia turned into an ocean eventually called the Yapitas, and we'll talk a little bit more in about a minute. These ridges of rock are prominent in the southern Islay, and a lot of the original distilleries were hidden in the ridges. I'll show you some pictures of these ridges in a second, next picture, yes, here's one. This is the igneous rocks here on the left-hand side, and there's a ridge of igneous rocks over here with a low ground between where these metasediments are. This is sort of metamod stones and slates, things in here which erode out more than these hard igneous rocks forming the intrusions, and the distilleries in the past, the legal ones were all located in here. This was probably a lot more wooded, and you could hide a distillery away from the taxman in these little places here, and that's why there's still a lot of distilleries there. There were the three or four that became legal, whereas all the rest obviously disappeared. It's also thought that some of these early distilleries, sort of using peat for firing the malt and heating the malt, which we do now, which gives the isler its whisky, its prominent pronounced peat taste. A lot of these early distilleries, these illegal ones, use charcoal because it didn't produce as much smoke, and you could hide away your charcoal distillery in the woods and make whisky until the cows came home. These are the sills. These are the igneous rocks here. This is meta igneous rock here, and it's been quite altered at the bottom here. These are the metasediments here that it's intruded into, and there's been a lot of work that some of my other researchers on Islay are doing is to understand the chemistry of these and how much carbon dioxide is created in the mountain building process that contributes to the carbon cycle. So another study that's all about earth climate and earth history and how geology and climate are intimately related. Yes, it's an interesting study area. Just a final bit on this area. This is a long strike from Port Ellen up near a place called Aros Bay. This is Kildalton Cross, which is made out of a beautiful eighth-century cross really well preserved, and it's made out of the same rock in these sills. In the literature you'll call it, it's called epidiariot. It's a term that's not used anymore. It's a metabase site or a metadolariot. It's a basaltic rock that's been metamorphosed. It's quite green and fine grained here and it's often used. All of these Celtic crosses and things across the whole of Argyll are made from this igneous rock. The so-called epidiariot, or the metabase site. This is a particularly fine example. I mentioned that these ridges and these bay and these glens between them are quite prominent. There's a bay that is formed here in the soft rocks here called Glasuig. This is Glasuig. This was one of the few places that German U-boats in World War I used to anchor, get fresh water and rustle sheep. The local farmers used to spot Germans stealing their sheep and disappearing off in the U-boats. This is known locally as U-boat Bay. These igneous rocks were formed like this. They were formed by molten magma rising up. As a new ocean is created, a new basin is created. Basalt rises up in dikes. These are vertical dikes, like this one that is on the south coast near Lagavulin. It rises up and it reaches a sort of height. This is the sea here. It spreads out into these sills. Then more sediment is piled on top. Another phase of dike intrusion happens. Another pulse. It rises up. Can't get any further and spreads out. That's why we get this pattern that you saw in the original geological map of sills. They've all been tipped up. They now actually all rotated about 30 or 40 degrees in this sort of orientation. That's how they all started. They're folding that's happened. These were intrusions during sedimentation. It's quite a nice story. The sea water has reacted with some of these sills. There's some very good chemistry going on in the sills at the time of intrusion. By 550 million years ago, the Dalaradian was been deposited on the edge of the continent. Rodinio was no more. Rodinio was no more. Rodinio was no more. Rodinio was no more. Rodinio was no more. Rodinio was no more. Rodinio was no more. Rodinio was no more. Rodinio was no more. Rodinio was no more. Rodinio was no more. Rodinio was no more. Rodinio was no more. Rodinio was no more. Rodinio was no more. Rodinio was no more. Rodinio was no more. Rodinio was no more. and that's part of the reason why the explosion of life in the Cambrian. Because we've got a lot of continental shelf, some of it are quite low latitudes and the warm waters, shallow waters, plenty of places for life to evolve into. And after the ocean was opening, England was forming over here, the earliest oldest rocks in England are about... In Wales, south Ireland are about 600 million years old. 600 miliwn i'r oed. So, o'r tîm, most o'r Scotland had formed by then, but England hadn't. And England was a long way away on another continent at the time. There were 3,000 miles apart. Eventually, I'm not going to go into the story today, but the Aepatis Ocean, like the Pacific Ocean, was at once an expanding ocean. It's now a closing ocean, the Aepatis Ocean eventually closed at 400 million years old ago. And England collided into Scotland and it joined up with Scotland at a round about the same as the political boundary today. So, the southern uplands line, the southern part of the southern uplands, is the boundary in England and Scotland as it is geologically. Yes, that collision formed the Caledonian Mountains. So, 470 million years ago, those of you who know your geological time periods, that's all division. In the all division period, it was when Scotland had mountains as high as Everest, which is Everest. And this is perhaps a juror about the size of Everest. It's a nice, faked picture, but nevertheless, it shows the scale of the mountains. They were big mountains. This collision that happened when the Aepatis closed caused a large mountain belt to form, which has now been eroded away. And what we see today are the stumps of these mountains here. These are the folds I showed you in the first picture. So, the collision caused crumpling of the rocks folding of the rocks. You can see these rocks are bent and folded. This is at Sarago Bay. There's a lovely fold here in the rocks here. So, this is... Folding wasn't too dramatic on either. It was quite... Further, as you come near the collision zone to sort of Loch Lomond area, you get a lot more deformation, a lot more tighter folding. But these folds were like gentle rocks in the carpet here. They were quite gentle. Just to sort of move on geologically from the all division, right up to the tertiary. This is 50 or 60 million years ago on the north coast of Isla. We get these dikes. Remember, I showed you some dikes earlier? These are vertical sheets of igneous rock intruded into the sedimentary rocks. So, the sedimentary rocks are... This is the bottom I have on Dolomite again. And then you get these massive cracks forming and igneous rock, molten rock, forcing its way up into these cracks. They're quite... On the north coast of Isla, they're a beautiful sort of very stunning feature of the north coast. They obviously erode less than the Dolomitic rocks, Dolomitic rocks surrounding them. And this all happened at about the time of the meteorite collision at the end of the Cretaceous. So, round about 60 odd, 65 million years ago, there was a huge amount of volcanism going on in Scotland. A lot of it in fissures. And a lot of these fissures are now occupied by dikes, which trend this way. And the dikes I've just shown you, trended this way across Isla, across Dura, across there. A lot of the dikes radiate out from volcanic centres that were situated in Skye, on the Merchan, Marl and the Antrim Plateau has also a lot of lava as well. And these dikes, the ones you see on Isla, probably come from a submerged volcano underneath the... I've forgotten its name. The Blackstone's Bank offshore, just been out by the Scary War Lighthouse. There's a submerged volcanic complex. It's probably like a submerged version of Skye, but it's underwater. And there was a big volcano complex here, and these dikes were coming out. And this is all part of the opening of the North Atlantic. Here's a map of the North Atlantic. So, the UK continental shelf goes right out past Rockall Hatten Bank. And if you go to this point, all this is Oceanic Crust, new oceanic crust that's formed in the last 50 million years. And this is new crust forming right down the middle of Iceland. And you can age date this is 0, 10, 15, 20, 25, up to about 50 million years. So, this is quite a new ocean basin formed 50 million years ago. We were right next to Greenland. Well, the edge of the continental shelf was. So, the continent now, we keep thinking it's here, but it's actually way out here. This was the bit that was joined into Greenland 50 on 60 million years ago. How are we doing for time? Yeah, just about to finish, at the very end of geological time, we are now in the current ice age, but 25,000 years ago, Isla was covered in ice, Scotland was covered in ice, the British Irish ice sheet was contiguous with the Scandinavian ice sheet. It covered quite across the North Channel, Northern Ireland, Middle Ireland was all covered in ice. And most of the debris from Scotland is actually out here. All the erosion products of this ice sheet are actually stuck out here and these big fans of rock deep on the edge of the, off the edges of the continental shelf. On Isla, there are evidence by, I saw that you showed you the caves. These are the Ruiz beaches. There's actually a terrace above that with a second beach. So, there's a complex geological deglaciation history on Isla that's subject to many studies and it's a lot of good interest to geomorphologists on Isla. And, but more of Isla is when it's not got some line stone on it. A lot of Isla is covered in this stuff, which is glacial, this is modern till. You remember I showed you the 700 million year old till, a lot of Isla is covered in this stuff, which is difficult to grow on. And if you get a lot of this stuff, this till, it's all boulder clay, as it's called. It's a sort of a nightmare. But where it's, where you get glacial outwash gravels, sandur in sort of Iceland, you get these gravels and you got a lot of gravels on Isla and sands that were deposited by meltwater rivers flowing off the ice sheets. This is a channel, a gravel channel. These are sands, the holes are sand martin nests. And it's a lovely place to go and watch sand martins where they love the sand. They don't like the gravel so much, but they love the sand. The beauty of these is that they're very good for growing barley and Calhomann distillery own the land around the distillery now. And there's a lot of barley grown because this is good, well-drained gravels. The tills and things are up on here and is rubbish up here on the hills with bare rock and till. But down in here where you get these glacial outwash gravels and a bit of windblown sand and stuff mixed in with it. Yeah, well-drained soils and grow good barley for whiskey around about Calhomann. The other interesting thing at some of these tills, this is a glacial marine till. It's actually been deposited by a snout of a glacier into the sea. It's got flints in it and these are flints that were found in here. We think these flints have come down the glacial stream from Mull and they were picked up by mesolithic hunter-gatherers after the ice. 8,000 years ago, these rocks were these deposits and the beach deposits that were formed by the erosion of these were very important to the hunter-gatherers of the first after the ice inhabitants of Ila, 8,000 years ago in the mesolithic. And there's a lot of mesolithic study being done on Ila. In fact, these are 8,000-year-old ones, but there has been found a sort of tundra hunting camp that's probably 11,000 years old on the east coast of Ila. So the sort of archaeology and the sort of mesolithic into the neolithic archaeology of Ila is really interesting and flint was a key part of it because flints rare in the western hebrides. And they would obviously if and when they found it, it became an important resource for the mesolithic hunter-gatherers. So that's pretty much it. As you say, I have written a book on it with Roger and Alastair. It covers these excursions. We've seen most of the rocks on these excursions. I am in the process of writing volume two to cover some nice excursions on Dura, three on Collins and a few more on Ila to sort of complement it. So and I might rewrite and re-issue the first edition of this. This is a 2017 updated edition with its whiskey recommendation. Each walk has a whiskey recommendation. And that's where we are now. Time for a dram. Thank you very much. Thank you very much, David. Fascinating talk. I think maybe if we we've got a few questions have come in already, but perhaps if we could maybe wait for five minutes to give people a chance to put in any other questions they might have, give you a chance to have a dram and wet your throats again. And so I'll start again in 8.30. And if anyone has any questions, please use the Q&A tab. Type your question into there. And if there are other questions that you see already there that you're interested in, please I'll vote them so that we can see what people are interested in. I'll meet myself again for moments and back with you in four minutes. Thank you. Hello. Oh, OK. So we've got several questions have come in, so I'll read them out and if you then want to give us your answers for those, please. OK, I've got them on my screen. You probably don't need to read. You can read them if you like, but yeah. But read them out, but I have them on my screen. That's great. If you'd like to read them, there's a couple that have come in through the chats rather than through the Q&A. But if you're happy to read them, then that's fine. We'll go with that. OK, I'm just I'm just trying to think where I start. OK, I'm just at the top of my list here. I've got Eilor distiller is a sped across a very different rock types. Producer whisky with a relatively similar taste, as it suggests that water chemistry is very little effect for the use of peat drying the grain. That is an interesting question. I mean, peat drying the grain is the main reason for the the peatiness of Eilor whisky. Obviously, some whiskies aren't peaty on Eilor. Brooklady standard whisky is not peated. Neither is Bunaharvin. So, yes, the whisky, the peating and the barrels have a huge effect more so than the water chemistry. But I think the water chemistry is interesting. And yes, it's I mean, ardbeg, for example, has quite a high humus content because the water sits in a muddy peaty lock for a long time before it gets into distillery. And as a high humus content, we think, probably gives a sweeter whisky. So there is changes at the margin, I would say, with the geology in the whisky. Yeah, most of the Eilor water is in the distiller, is from the is basically rainwater with a bit of peat in it. But the peat in the water does not give the peat taste. It's the burning of the peat to fire and dry the malt. That causes the phenols to come into the whisky, which phenols, being volatile chemicals, do transfer through the still process. Someone said the geology I ended up with a reason why there are so many distilleries. Well, there is a geological reason, as I mentioned, about the illegal stills on the island. And they maintain themselves there. A lot of it's just, you know, since then, there's just been more distilleries because there's an infrastructure for it as well. And there's a new distillery, whether COVID-19 will change that. There's a new one planned for Port Ellen, near Port Ellen, and Port Ellen is going to open again. So there's, and there's Ardnohau is a brand new one as well. So there's a piggybacking effect going on with more and more. The question from Pat Monaghan, could you say a little bit about the fossil record? Well, basically the stromatolites are the main indication of life. And someone's mentioning here just earlier about Martin Brazier, unfortunately, died recently. Wormcast, it's not in the blobs along its length. He later rescinded that interpretation and believed it was more of a diagenetic or a chemical effect post burial rather than a wormcast. So that we did at the time, write a paper on it, saying it was one of the oldest fossils. But in the same formation, this is the Bonahavn Dolomite, where I mentioned where the stromatolites are, is where Martin found this cast or ledged cast. And in Fairchild at Birmingham has done a lot of work on Isla in the carbonates and reckons that there are indications of microfossils, of small sort of planktonic type things that have been preserved in, were preserved originally in Glauconite, but now in Micah in the aftermath of autism, in the same rocks that Martin found his wormcast. So, yeah, there's this possibility that there's also some things called acrotarchs as well, which are not really diagnostic, but there certainly was life in these seas. It was primitive life, life, not as we know it, dominated by algal stuff, but there would have been soft-bodied things, we know later on after the Ice Age, we get into the Edycarian where we do get around the world more sort of fossils. But say on Isla, we've got this minor indications of life and the major indication being the stromatolites, yeah. Someone's, Tricia, has said about limestone as a thin layer, so it is quite thin in places. Certainly a lot of good, good, good, but in places that it's a combination of the fact that there's, where the limestone has got some till on it, you get a sort of a more lime in the glacial deposits so that the glacial deposits have some fertility in it. Certainly it grows good grass, so it's quite good for the cattle and the sheep, and they're the ones that do a lot of grazing on the limestone. It's very poor grazing into the quartzites, which are very thin, very poor acid soil, so the limestone is good for grazing. Yeah, so, I mean, Isla, it has grown, as you say, over the years, hundreds of years, it has grown grains and it's been a relatively fertile, I wouldn't say it's very fertile, but it's certainly compared with other parts of the Western Hebrides, it certainly has fertility. Felicity's asked about the critical boundaries. I love this, I love this story. It's been around the Apatus suture, as it's called, the joining up of the collision of the closure of the Apatus ocean does form the boundary. I mean, the southern uplands are the trench deposits that were in the oceanic trench that fought, that was in the subduction zone that existed between England and Scotland, and England came up and collided with it and pushed up and folded all the rocks of the trench, which is the southern uplands and the Lake District, and things were volcanic arcs way away across the ocean at one stage, and they joined up, so, yeah, Scandinavia, I think the Apatus suture is not just an English Scottish thing, it occurs right across into the Caledoniaides, as they called, in Northern Scandinavia and right across into the Appalachians as well, so it's a big orogenic belt that occurred at that time as this big ocean called the Apatus closed, enclosed in a complicated way. Fantastic examples of the Apatus suture in Nova Scotia in Newfoundland, if you're ever over that part of the world. Still an ice age, I think we are. If you define ice, most of the time in the Earth's history, it has not had ice. Ice is unusual, yeah? You have some ice ages in the Precambrian that we've just looked at. There's a bit of an ice age in the, certainly in southern hemisphere, ice age in the Carboniferous, and there's an ice age in the, called the late paleo, the mid paleozoic ice house in the Old Division, or that's about it. So yes, so yes, we have ice at the poles, so we're in an ice age technically, and it could, just because we don't have ice here today at low levels, doesn't mean it won't come back again. So yeah, I think geologically we're still in the ice age. Someone's asked about interesting fossils. I think I've covered the fossil discussion about the stromata, stromatae lights. Is there a choice of proximity to Bregladi due to the geology or the whisky? My choice, okay, good one. Anywhere on island is proximal to a distillery. In fact, I can see three from my house, it's just coincidence. It was just a nice, I saw the site on the internet, went over on my bike and rang out my wife and said, I like this place, it's by this field and we did. And it just happens to be just up the hill from Bregladi and next door to the head distiller, he lives next door. Where are we with respect to the formation of a new supercon? That's a group on, I mean, the Pacific Ocean will close, but the Atlantic Ocean will open and then it will close. So I think some reconstructions have been done and the sort of psychicity, if you keep moving these things around, eventually they come together and they split apart. It's just a sort of almost a super cycle really. And a couple of hundred million years, if you were still around, yeah, might have got a, there have been people have done some work on reconstructions of what would happen if you carry on with plate tectonics into the future, where is it all going to end up? Yes. Someone's asked the nice rocks in the volcanic arc are rarely, rarely seen in Scotland, that's true. We have the only pretty much, I say we've got the patch on Islay, there's a tiny patch on Collins-Ee, there's a little patch off Northern Ireland. Yeah, I mean, there's a whole group of rocks in Norway called the Trans Scandinavian Ignis Belt and also the Pheco-Fennian Belt. So there are lots of rocks of this age in the Baltic area and also obviously in Southern Greenland where they're beautifully exposed and it's all part of the same arc. So I think, yeah, so the whole of the arc system that existed on the Southern, probably the Southern flank, it's probably difficult to relate modern to paleo latitudes and things and directions, but yes, on the flank of this Nuna Columbia Supercontinent, there was a large volcanic arc, like we get round the Pacific today, you get the volcanic arc all the way from Camchacta round right through the Southern Pacific, it's all part of the same arc complex, which is sort of on the age of the Pacific, age of the Asian plate, so yeah, it's a sort of, there's lots of similarities. Two crosses on Islay, yeah, there's actually quite a few, but Kildalton is the key one. If you're interested in Celtic crosses, it's a good one. There's other ones up at Kilnave on the north side and there are, if you want to get into this, there's a lot of publications on the archaeology and early history of Islay. David Caldwell from the National Museum Service is your expert on this. He's written some really good books on that part of the, on the sort of medieval to recent history of Islay. He's got a gazetteer and a thing called Land of the Lordship. And yeah, if you're really interested in Islay archaeology and early history, there's stuff there. And if you're interested in the Mesolithic, Stephen Nysan has written some fantastic books and if you look at Islay heritage, you've got a lot of information there on Islay heritage's website about and then Finlaggan as well that David's very, very much involved in dinosaurs. Everyone asked dinosaur questions. No, but, but I mean, some of the slides I took out of the lecture realizing I was going on for ages. I did take them out just before I left, before I started. We've got ammonites offshore Port Charlotte as you've been picked up by scallop dredges. So we believe there are dinosaur age rocks, i.e. Jurassic rocks offshore in the, around Islay. A lot of the sea around Islay is actually forming, is formed on an ocean, on subsiding basins of younger rocks. So the reason why the islands are there is that because it's the harder rocks sticking up and the softer rocks from the Jurassic and the Triassic are in the basins and you can go on soft Triassic Jurassic rocks from Islay right across to Northern Ireland. And there are ammonites often because they're a common fossil. I guess if you dredged enough you might find a dinosaur bone. And they probably would have walked around on Islay. We would reckon that Islay would have been a desert and then a shallow sea may have covered it. Round Lockendow certainly was a sort of swampy pond 250 million years ago. Yep, just that the rocks are not exposed whereas they are certainly further north onto sky. Yeah, so we do get some fossils there. The erosion 700 million years do down the CO2. Yeah, that's into the silicate weathering. There's a lot of silicate weathering of turning of clay and then the formation of carbonates in the sea from the calcium and the sodium that have come down off the mountain. So the whole process of weathering, the weathering cycle, if it's very intense we'll draw down CO2 and sequester it into limestones. So eventually it ends up in the limestones in the sea. So if you get that sort of process a lot of weathering going on, a lot of clays being formed from fell spars you will end up with a lot less CO2 in the atmosphere because it's absorbed and sequestered into limestone. I've done the dinosaur one. What's going on with the small sets of rocks in the coastal part of Kildelton area? These are the dite. These are the sills. Remember I was saying about the sills that form the high ground? So these protruding lines of rocks come out of the big distillery. They are these igneous or meta-igneous rocks, the sills that were formed of igneous basaltic rock that was the precursor to the formation of oceanic crust in the Apertas Ocean. So these protruding lines of rocks, they circle and enclose for Ellen Bay, their nightmare for the Kalmack ferry captains to get in to Port Ellen because of these skerries that are these submerged lines of the hard rock that form these, that form from these sills on these igneous intrusions. And they're all around that south coast. It's around Arbeg, Lefroy, Lagavulin Bay. Lagavulin Bay is formed from the soft rocks whereas the edges, the prometries on the edge of the bay that form the mouth of the bay are the hard rocks that once held duns and Duniveig Castle is still there as a prominent thing on the hard rocks. So the geology really does affect the topography and affects the way that humans have used the topography to build and live on. Isla silver, yes, but gold, no, we haven't got any gold on that, not that we know of. Yeah, yeah, be nice if we was, but I think silver and some zinc and are associated with the lead. There's some salarite and some calcopyrite copper mineralisation that no gold. The question really nice, are there not so many layers of Dalradian rocks supposed to know it? Yes, I think underneath the Dalradian equivalence in Norway, there's more nice than, yes, you see deeper into the core of the Caledonian mountains. There is, remember a lot of the nice in Scotland that we do a lot of nice, we do get a lot of nice in Scotland, it's the Louisiana nice which is two and a half to three billion years old. So the whole north of the Great Glen Fault, the basement rocks there are the Louisiana which is older than the Rins, right? So the Rins is 1.8 billion and we do get some of that in parts of Norway. But a lot of the northern part of Scotland is the nicest older again than the Rins. The Rins is slightly younger. Originally when you look at the maps that the, those wonderful old Victorian Edwardian geologists sort of discovered, they all, the pink rocks, they all thought it was until 1988, it was always thought that the Rins was Louisian. It was always thought to be the same age as the Louisian and it was just because it's pink and nice-os, it just looked the same and why wouldn't you? It wasn't until modern radiometric dating using uranium and lead in zirconium and zircon minerals that in the 1980s, early 90s that we actually realised that the Rins was significantly younger than the Louisian. Still old, still very old, but certainly younger than the Louisian. You have liquid gold in abundance. Why would you want the metallic stuff? Well, it's not that. It's not indeed. Thank you very much for this, David. That's a phenomenal talk. We've not done a virtual lecture before and this has gone really well. There's very many complimentary comments in the chat here from people who've enjoyed the talk. I've had a taste of Isla before from this whiskey. I've never had a taste of it through the rocks before and I found this absolutely fascinating. We've learnt a lot from it and certainly have to go and visit it now, I think. So thank you very much for doing this. We would normally give us a small token of our appreciation in the hall, but I'll ask George to send something out to you. That's just a small token of our thanks. Thank you. So everyone in the audience, it looks like this is how we're going to be doing lectures at least until the end of the year, I would imagine. So if you have had any problems with this, anything that you think has worked well and you think has worked better, please do let us know through the chat. Please do let us know. You can email George at info at royalfield.org and we will take on board any comments and try to ensure that things work as smoothly as this for the rest of our lecture series. On that, thank you very much.