 Roeddwn i'n meddwl y gwirionedd ysgrifennu pan wrth yng Nghyrgrifennu Llyfrgell yn y West Coast of Britain, ac mae'n fydda i'r gweithio ddydd ffyrdd y gweithio bod y gweithio wedi gwneud bod yn ymgyrch yn ystyried ac mae ydych i gael ei ddweud y gweithio ar gyfer mor gweithgod yn yr arddangos. A oedd y gweithio ar gyfer y prif iawn, a yna pethau'r gweithio ar gyfer y gweithgol, y gallwn gwneud hynny i gweithio ar gyfer y Gweithgol Gweithgol. Felly, y ffocos eich bwysig yw'r ystyried y mewn Llywodraeth Nid, y Llywodraeth Nell, y Llywodraeth Swerth, y Llywodraeth Cymru, mae'r rhai bwysig yw'r ymwysig yw'r ymwysig yw'r cardiwn. Mae'r projekty nesaf ar y ffóch i'r ym 2018, ac yn cyfleoedd ar Ffoeidgyn Ysbryd, rhai bydd yn y Llywodraeth Merin. Yn ym Mhysig, o fïdd y ffordd, mae'r pwysig o'r plan. fel byddwch yn ystod o'r pethau sydd wedi bod yn cael ei ddweud â'r ddod y cyfrifol am y ddefnyddio. Ond y gallwn o'r cyfrifol, gofynodd iawn, byddwn yn ystod y qufain o gweithio i gael 30 o'r ddygol sy'n gyfrifol o'r Llyfrgell Pinga ac roedd yn ymryd i'r Cedrydd i'r 50 metr. A'r co-authorsau ar St Andrews, Richard Bates a Sarah Boyd, yn ymweld i'r modelu hyfforddiadau hyfforddiadau i gael o'r brifysgol. Felly, mae'n mynd i gael ei fod i'r gwaith i'r pari. A Cardigan Bay, a dyna ymlaen yma, yn y reddoch, yn ymlaen i'r gweithio ar y dyfodol yma. Felly, mae Cardigan Bay? Mae, yma, yna, yng Nghymru yn y fawr hyn ymlaen, ac yw'r gweithio'r stori, yw'r gwwantraig gwaelod, y rhaid, ymlaen ymlaen i'r ddechrau. Mae'n mynd i'r stori. Mae'n mynd i'r stori'r stori'r stori'r stori'r greif a myfyrdd o'r llansgap sydd wedi'u cyfnod o'r gennau ar hyn o'r 1000 o'r ymgyrch. A oes y dychydig o'r ffyrdd ymgyrch yn ffyrdd a'r llansgap erbyn, dyna'r ffordd o'r llansgap mewn cyfnod ymgyrch yn ymgyrch. Ymgyrch yn gyfer y gyfrifod mlynedd yn ymgyrch yn ffyrdd ar gyfer ymgyrch yn ymgyrch yn ymgyrch. A oes ymgyrch yn fwyaf ar gyfer ymgyrch o'r llansgap a'r ymgyrch yn ymgyrch, o'r gweithio'r gweithio, ym mhyself yn ymlaen i'r gweithio? Felly, mae'n gwneud o'r gwneud o'r Lansgêffa Llywodraeth yn Ddenmark yn ymddorol o'r 2,000 gyrs. A'r cyfnod o'r gweithio'r gweithio'r Lansgêffa Llywodraeth yn ymddorol. A'n gweithio'r gweithio'r Loss Fronteer o'r objectifau, o'r rhai gweithio ar y maen nhw, o'r pethau acrateraidd, ymddorol o'r gweithio'r gweithio'r gweithio, i'w ddiwethaf hyn yn y Llandd Llywodraeth Llywodraethol, a heb 27,000 rheswm yn fawr, a'r Llywodraeth Llywodraeth er oedden nhw'n 125 m o'r gael y prysyn. Yn ymweld, mae'n meddwl i'r Llandd Llywodraeth a'r perspective arall, ar y perspective geologiogol, mae'n meddwl i'r perspective arLOG. Mae Llywodraeth Llywodraeth yn y ddiwedd y llan lleig, a mae'r Llywodraeth Llywodraeth yn y Llywodraeth Llywodraeth, yn y Llywodraeth Llywodraeth, pech Noodles and Retreatary but before flooding had occurred. We have an incompletic archaeological record of the late Upper Paleolithic, Mesoddippic, and the transition into the Neolithic for the northwest Europe. This also affects a current archaeological record in that existing finds may not be in their proper context if we don't understand where the coastlines, migration routes and populations centers were. Bringing you back to Cardigan Bay, what I'll do now is go through a little bit of o bets o ran yr ysgol tdod yn oedd ddyn ni'n wych ar eich maen nhw.pereddau hyd yn gymryd yn cyfarfod fel gynyddiaeth, felly mae'r brerau'r Dor shyner oedd gyda hyn yn cael ei cyflogon a phrygaethau yn hollwn i ddechrau C yn hyn, ac y ddau ddod yn cael ei gael y ddechrau. A erioed o bwysig, mae'r brerau 15-30 metwy o bwysig a chyflogn i ddechrau C ar y ddechrau i ddechrau C ac y ddechrau ar y ddechrau C yn cael eu gwahoged o 15-10 km ydw o'r gyflogon. Llywodraethau'n ddod yng Nghymru, y llwyr yng Nghymru, fydd yw Ilywodraeth Ryddi, a'u gŷtol wedi'i gŷtol yn ymgynghwyl yng Nghymru, a fe yw Llywodraeth Gleisiwm yn gweithio'r Ysgrifennu Gwylch. Rydyn ni'n gyrdd yna'r sefydlingio'r geodag o'r yma. Oeddi'r image gyda'r lithologiaidd a'r image gyda'r roi'r roi. Oeddi'r sefydliadau yma, mae'r image ac mae'r image mae'r roi'r roi'r roi, ddifen y ffordd o wisio zoics yn ymdill. Roedd yma ymwneud yllyn i fynd ond i wneud ystod o'r roi gallwn Ysbyddoedd Llywodraeth. Ar y cyflwydd y Llywodraeth yn y lleol iawn. Mae ydych chi hyn yn lleol iawn i'w tyll i ymddill a'r rhaglen gyn nós, sy'n fawr a'r ysbyddoedd iawn i fynd y llyrdd hynny ac mae'r pethau iawn i welith i'r llyrdd ac mae hynny nesaf i'r thymau o ddefnyddu'r llyrdd hynny. Lleol yn y lleid i amweithio y plant yn cyfydd iawn dwi'n droi chi'n…. … broses bod y borghols yn wych wedi'i gweld bwysig... … y ddrwy'r cyflaes iawn inyddio cychwilau am gyfan ei sylwyddiadau… … a'r lliw gweithio'n ei wleidio gyda siarad… … mae'n swyddfa'r bobl cyflaesiaid maes yma yn golygu... … y broses wedi cyflaesiaid. A gallwn ddodd i'r cyflaesiaid yma yn y bobl ledd. A'r bobl ledd yn 73.42 ac yn 17.27. ydych chi'n gilydd y bwysig. Felly mae hyn yn hyn o'r cyfrifogol yn 1977 a oedd yw'n ddysgrifogol yn gwybod ddau'r ddweud i gweithio o'r lluniau ddechrau'r ffordd. Dyna un o'r 14-gwisio'r ddechrau yn y lwyf ddweud o'r 27, a ddweud y gweithio yw 8.740, a'r bwysig i'r bwysig i'r bwysig i ym 9.5-10,000 yma. Mwdliwch ddweud o'r cyfrifogol i Sero Boyd yn Richard Bates, at y gyfodd yma, has helped to redefine our understanding of the teresial landscape and how long lived it was. So the paleotopography was modeled for Cardigan Bay for six time intervals between 11,000 years and 6,000 years BP. Interpolated prediction services of relative sea level were created using existing sea level index point databases and pathometry. And also paleo river networks were modeled. And in these images, the blue is the marine realm and also we've got rivers on there as well. And the light browns are the low lying area that was exposed at the subsequent times. And the green show present day configurations. And this modelling suggests that sea level in the study area was roughly 20 minus 20 meters at around 10,000 years before present. And that between 11,000 years and 9,000 years before present, we lose an area roughly 3,000 square kilometers to the sea. And to put that in context, Wales is 20,000 square kilometers. So it's quite a large area. And that the present day geometry of the coastline was established between 7.5 and 6,000 years BP. What we also see is that the present river systems, the glass slain, the Madoch Dovey, let me make sure I'm pointing the right ones, the Madoch Dovey, the right door on the estrus, extended across this terrestrial landscape in a northeast southwest trend. And we also know that the now submerged offshore reaches of those systems have much shallower gradients than the onshore counterparts. And it's also worth noting from this that the coastline around the Tavey, this is the river Tavey here, has been stable for much longer than those of the rivers to the north. So focusing in on the geophysical data set we have. The Pinga survey from 2018 focused in on a deep within the bathymetry known as trawling ground. So that's here between the rivers Dovey and the Tavey or between Aberystwyth and Cardigan. And from the modelling and from a couple of Pinga lines that had already been taken in the 1960s, we know that underneath this relative deep are the submerged reaches of the ridal estrus, river system. The survey data here is shown in black and the survey data is decimetre scale resolution and like I've said previously we could image down to about 50 metres. Caws from this area were not successfully obtained but we have used those boreholes described and analysed in Haines et al. 1977. So the 7342 and the ZZ27 crawls. And what we see from the seismic data is a buried valley system with highly variable geomorphology. And in the seismic lines are showing here the purple lines at the top of the sea bed, the present sea bed and the red lines are the base of this buried valley feature. The main valley deepens towards the south west from 7 metres depth to 20 metres depth narrowing to a kilometre's width and previous interpretations have interpreted it as a buried water channel. And just briefly why are these features potentially good for offshore archaeology. In simplest terms they provide accommodation for sedimentary layers as we can sort of just about see in this image these sedimentary layers to build up as sea level rises and we'll come back to that at the end. And so we will take a closer look at the acoustic character of one of these lines. So this is a north west south east cross section across the valley and the vertical scale is in two-way time milliseconds. So it's not completely equivalent to death but we can get a good idea of what it looks like down there below the sea bed. So below the red horizon we have chaotic irregular acoustic character to the east and more clearly bedded reflections to the west. Above the red horizon we have two main acoustic fashies, a weak transparent fill which I'm going to point to now just at the base of here and on this side as well and these reflections are dipping. And on top of that we have sub-horizontal laminates that have a stronger acoustic character and they overlap onto these earlier layers sort of infilling the area. And all of that is truncated by this green reflection I've pointed out here at the top and that's a few metres below the sea bed and that sort of truncates everything underneath. What I should say is that we do have some issues with shallow gas in the area which affects our ability to complete the image everything, the stratigraphy and the structure of the area and so there is a potential that we're not seeing the whole story in our data set and this needs more work. And so when we map out the base of the valley feature we get a depth structure map, looks like this. And so on the left is a 3D representation of area A which is where we have the highest density of data and on the left is our 2D map of the original or the raw interpretation that we've done in Kingdom Suite. And just to mention this area has good data coverage and as we go south the coverage is limited and the data quality also is reduced because of weather I think it was. So with additional seismic things could change in terms of our interpretation. So in each of the images the light oranges and the reds are where the surface is shallowest so closest to the present sea surface and the greens and the blues are where we've got deeper sections. And the main features again are that we're narrowing and deepening towards the south in the main channel and we have a shallow area to the north of the valley and we're also able to image where the aeron drained into the valley system. We also have an area that's very shallow within the north of the valley. Again there may be issues with shallow gas in here so we do need to do more work on this. The two boreholes that we've used in this study said said 27 is just missed by our survey but we do intersect 7342 which penetrates a value feature which we think is the same one as imaged up in area A but the seismic routine is a bit sketchy so we really need some more data to completely confirm this but it's likely that the seismic character is very similar. And we've used the existing boreholes to give some paleoenvironmental meaning to all those wiggly lines I've just shown you in the seismic sections. So said 27 setting we're pretty sure it's on the flank of the valley or on a relative topographic height at the flank of the valley. It's a short call that encountered Welsh till at the base. It's overlaid by a peat associated with salt marsh conditions and that was dated to around 9.5,000 years ago. Calibrated and this in itself is overlaid by laminated clays and silts that have come back as we associate with brackish conditions and become increasingly marine as we go up the core with fully marine conditions at the top and we think these major changes within the cores are reflected within the seismic data so that the red and the green horizons are essentially where we're getting big changes in seismic character but also where we're getting the major changes the major and conformities within the core. And borehole 7342 is a bit different it's within the valley system itself so this is an example of where sort of location it's in it's in the tunnel axis and it penetrates all the way down to lower paleozoic bedrock at 60 meters which we don't image here it's below our seismic section and it represents a 30 meter sequence of quaternary and horizon sediments above the Irish Sea, above the Irish Sea Till at 51.5 meters is a 1 meter thick unit of well-bedded Shelly, sorry not Shelly, Shelly gravelly sands and they are seen outside the area of the borehole in the seismic data to thicken quite substantially away from the borehole and a forearm analysis of this section by Haynes et al 1977 interpreted them as channel sands and within the setting of a main channel estuary with also the cold water species so Haynes et al suggested a date of about 11,000 to 12,000 years before present but we don't have any dates that was based on correlation to onshore records but the most important thing here is that by the lake glacial the area is already under marine influence which is backed up by the modelling that St Andrew's team have done and so to apply that information to our seismic sections what we're looking at here is within the main valley at location is horizontally bedded till, Irish Sea Till likely in this area anyway overlay by lake glacial channel sands and muds already marine influenced and separated those themselves are separated from the till by this strong amplitude continuous reflection that's shown in red and above that we've got an estrine infill onlapping onto these channel sands that are likely fluvial and tidal and on the flanks of the valley we have salt marshes, peat formation and wetlands and the green horizon is erosional and it delineates a changing environment for regime and switched to fully marine conditions so what have we learnt about the painting environment and the painting geography from what we've done so far until about 8000 years before present the riddle estriveneirol would tribut use of this long river corridor that's adjacent to the coastline offshore and is imaged within our seismic data set and we've been able to map out areas also that are areas of high relative topography versus areas of low top relative topography so that's what we're seeing in this map here so the darker greens are areas that are relatively high and would have been emergent for longer during the flooding of the area and also some minutes of interest linking it back to what's going on on the onshore is that brackish conditions at the Dovey at Borth which is in this location roughly around 11000 years before present when the coastline so basically we've got brackish conditions at Borth in the river Dovey 11000 years ago when the coastline was 20 kilometres to the west of this position and that means that we've got these long, narrow tidal estrives extending some considerable distance up catchment from the open coastline and the seaward part of these systems would have flooded during the Lake Glacial as attested by the cold climate fauna in Borthole 7342 and so bringing it back to archaeology some quick points on the archaeological potential from this initial work first of all the environment of this coastal plain that's now submerged in Cardigan Bay would have been highly productive a highly productive river in an estrine zone offering a highly suitable environment for supporting hunting and gathering communities and here we've got a block model or a block diagram showing the key features interpreted in the offshore landscape the main valley, its tidal channel flanked by salt marshes and these low forested interflues which would have been on the higher topography and we can sort of link that back to what we're seeing in the seismic data and our 3D structural map of the base of our valley it would be these areas as what we're talking about when we talk about low forested interflues and we've got the valley itself here and how this relates to preservation potential for archaeological material well Martin Bates mentioned earlier in his talk that there's a lot still unknown and in five years time we might be able to say a lot more about this however the longer the shorter bit is that within the valley itself we have a greater likelihood of preservation because there's greater subsidence and burial within the valley itself while these areas of higher topography though they were emerged for longer are much more likely to have been subject to erosion from the subsequent marine transgression and this area we've got to the north where we have this narrowing and shallowing of the valley could be important archaeologically elsewhere this type of area has provided resources and meeting places for mesolithic humans so all this will go into future planning of where to collect more data whether to do more surveys on seismic all of this information will be taken into account and to draw the presentation to a close these images are from the forthcoming book chapter led by Martin Bates and I massively oversimplify this sorry Martin so here we're showing the model coastal geomorphology as we've seen in previous slides from 10KABP and 8KABP with the early mesolithic sites plotted on them as green circles so these are the early mesolithic sites of west Wales in each one and just to say that these triangles are not sites they're forests what we see is there's a sort of relative lack of mesolithic sites within the invade shore of Cardinopay north and south so what could be the reason for this relative positive site is it just that the Cardigan bay plane was just a more attractive place to hang out than west Wales at the time I answer sort of hope we hope so and we want to go and find out but also there could be other things going on so it could be cultural and historical differences within the area onshore compared to the north and south so we're talking about land use development of the coast the culture of collectors and interested tourists and academics in these other areas in Pembrokeshire for instance and in sorry, and in north Wales and if this is the case well that's great also because there's even more potential in the onshore section as well between the Dovey and the Tavey either way we can now start looking at those existing sites onshore with this new data in mind and we can start contextualising existing sites so in conclusion modelling and geological data show that there was a terrestrial and habitable land in the Cardigan bay in the late of the Paleolithic and Mesolithic but it was largely flooded by 8,000 years before present all of the shallow boreholes and seismic data previously like shown here previously from the BGS database were gathered in the 60s and 70s so this was the first attempt in this area for two generations to collect data and I think we have a massive opportunity to learn from the work we're doing in the North Sea both in Southern River and in Brown Bank and apply it to this area and what we need is a coring sampling campaign and additional seismic to start to understand the paleo environment and geoarchaeology of this area and thus the late upper paleo paleolithic and mesolithic of the west coast of Britain so if you want to do this we need more funding to go and find out thank you very much thank you Rachel fantastic coming in all the time which is great so it gives us a little bit of time for questions Ben should I stop sharing or what's to do it's up to you I guess maybe leave it up for now in case there's anything you need to come back to in the questions I suppose so we've got a question from Mike F Stathew sorry Mike for I've mangled your Mike asks 8000 years ago would the top of the forest trees on Carnigan Bay still be above sea level 8000 years I'm not certain maybe Martin I don't know if Martin's here so Martin's more up to date with Martin and Richard with what's going on in the onshore section I might cut bully on the hot there I assume he's in the room so maybe while he's thinking about that to answer that one the models suggest that the near shore around the places we find in port the port is much younger much later but there is a strip along the shore just still visible at that time period very quickly after that the models would suggest we lose it can you still see my screen because actually it's on my screen as we speak so the 8000 model is there and you can see there's a little bit of a strip of land just where both is basically next question from Bjorn Nilsson from Lund thanks Rachel do you have any evidence of exposed moorlark tree stumps and trawls or other historic ethnographic evidence of terrestrial landscape archaeological findings so off shore there's not the same level of trawled finds that we see in the North Sea I know I've spoken to Richard and Marty about this a long time ago but you don't get the same amount of things coming up in the fishing nets and in the trawled nets as far as I know but again Richard might say different that's correct you do get some up in Liverpool by they've come up and aren't very well reported but other than that it's near short stuff again in the that was discovered I think and reported by Aberystwyth University a number of years ago but not from off in the trawling ground another question from Steen Hildebrandt could you clarify whether the channel was formed subglacially or after ice retreat again we haven't done I guess we haven't got to that position yet we're looking at data the data was relatively recently reprocessed so I'll be looking at that in the next few months so we might be able to say more about it in the future sorry everyone any more questions we're actually well in time which is great so just good people a couple of minutes there to maybe collect their thoughts see if anyone else has got any other comments there and it'd be great to see this kind of work done for Ireland for example you know where we've lost a lot of coast or plain I think you know again in questions of the Mezalithic in particular I don't know if some grey moorins in the room somewhere you know these questions of where our Mezalithic is in Ireland on the coast that's another project I think James Bonsaw has also had his eye on that one as well