Paviland and the ice edge

 Goat's Hole Cave, Paviland, on the Gower Peninsula.  Below: an artist's reconstruction of the laying out of the young man whose bones are now dated to c 26,000 years BP

I have done a few posts in the past about Paviland and the Red Lady -- use the search facility to find them.  In some recent posts I have been speculating about what might have happened in the Carmarthen bay and Cardigan Bay areas during the Early and Middle Devensian -- and Paviland is one of the few places where evidence from archaeology and geomorphology might come together to give us some answers.

A good summary of the state of knowledge about Paviland is found here:

http://www.britarch.ac.uk/ba/ba61/feat3.shtml

and there was a somewhat imaginative reconstruction or dramatisation of the interment of the young man (mistakenly referred to for many years as "The Red Lady") in the opening sequence of "The Story of Wales" on BBC1 the other evening.  (You can see this sequence on the BBC  iPlayer.)

http://www.bbc.co.uk/programmes/p00pj67h

http://www.bbc.co.uk/programmes/p00pd0jp

To quote from Stephen Aldhouse-Green:

At the time when the young man was ritually interred, there is no substantive evidence in this remote part of Europe for a human presence that was other than episodic. Indeed, faunal compositions and densities probably oscillated over time and space. Human presence in the British early Upper Palaeolithic may plausibly be linked to a 'biomass expansion', an overall increase in the availability of animals and other forms of food, centred on the 29th millennium. The coincidence of the dating of burnt bones to this period, combined with the presence of burnt Aurignacian artefacts, supports this as the most likely time for Aurignacian presence at Paviland. Radiocarbon dating of an Aurignacian bone spearpoint to around 28,000 bp at nearby Uphill lends additional weight to this interpretation.
Gravettian visitation is attested by a scatter of large tanged points occurring across southern Britain, including Paviland. Such points are generally dated to 28-27,000 BP, although their use may possibly extend down to the time of the 'Red Lady' burial..........

............ Restudy of the Goat's Hole lithic collections has confirmed material ranging from about 40,000 BP to about 13,000 BP (including Mousterian, leaf point, late Aurignacian, early Gravettian, Creswellian, and Final Upper Palaeolithic phases), although the earliest and latest phases are not dated by radiocarbon. Aurignacian finds form the dominant element. These artefacts were made from a range of imported and local raw materials.

So the signs are that there was possibly continuous -- or more likely intermittent -- occupation of this Carmarthen Bay coastal area right through from the Early Devensian to the Late Devensian.  The most favourable conditions for occupation might well have occurred during the episode known as the Upton Warren Interstadial.   Did the occupants of Goat's Hole and the other limestone caves around this coastal lowland (including the Caldey Island caves) also live here and die here at the peak of the Devensian glaciation, around 23,000 years ago?  With Devensian glaciers coming down from the Welsh valleys and creating end moraines not far from the position of the present coastline, did the hunters of the time occasionally stray onto the ice, or hunt along the ice edge?  Or was there such a hostile environment at the time that they retreated southwards, and returned once the glaciers had started to melt away?  And what is the relationship of Paviland Cave to the Paviland Moraine  (supposedly of Anglian age)  of Prof David Bowen?

Could Devensian ice have actually flowed across the mouth of the cave and sealed it off for a while?  The current consensus is that this did not happen, and that the ice edge lay maybe a couple of miles to the north, across the middle of the Gower Peninsula;  but I am not all that convinced by the evidence for that, and as I have said earlier, I think that Devensian ice might well have overridden Caldey Island and substantial parts of the territory now submerged beneath the waters of Carmarthen Bay.

Lots more questions.....

The bluestone argonauts -- why would they bother?

 A still from the BBC programme "The Story of Wales"

Last night we saw the first episode (number 1 of 6) of the BBC Wales / OU blockbuster series called "The Story of Wales" -- which dealt with prehistory.  In the section dealing with the Neolithic / Bronze Age some time was given to Prof John Koch, who made the point that the old idea of eastern tribal supremacy and conquest spreading westwards from the east and into the Celtic Fringe or Atlantic Seaboard was now discredited to be replaced by a view of the world in which the land was the least favoured option for moving about, with the early tribes (the Celts and their precursors) spreading gradually along the western coasts.  Then tribal trading contacts were maintained by sea rather than overland.  The view is now (according to Prof Koch) that trade, rather than invasion and conquest, was the driving force in the creation of what would later be "the Celtic World" of western Britain.

I have always thought that the idea of the human transport of the bluestones from West Wales to Stonehenge is underpinned by a presupposition that there was a dominant society in Wessex and a subservient tribal society in West Wales.  In other words, the Wessex tribes were more advanced and more powerful, leading to a situation in which they could collect stones from the far west with impunity, or on a whim, and that they had the manpower and technical expertise to do it -- or else that the western tribes might wish to carry the stones to their eastern neighbours as a form of tribute or homage. 

Might this version of events now need to be fundamentally revised?  If the Wessex tribes were not necessarily any more advanced or powerful than those of Pembrokeshire, and if the people of the latter area were perfectly happy, thank you very much, why would they bother to cart lots of very heavy stones all the way to Stonehenge?

It all gets very convoluted, and indeed MPP and his colleagues have explored this issue before, at the famous lecture in Newport last summer.  There, they argued for two very powerful tribal groups who came together in a great social and economic alliance -- in the first great political "unification."  The moving of the stones was the great symbolic act that cemented the union.   All highly fanciful -- see my posts here:

http://brian-mountainman.blogspot.com/2011/09/are-you-sitting-comfortably.html


http://brian-mountainman.blogspot.com/2011/10/stuff-of-nightmares.html

http://brian-mountainman.blogspot.com/2011/09/hq-of-nevern-valley-tribe.html

My problem with at least some of this is that I don't know how widely accepted this "revisionist" view of prehistory actually is.  As Wales and Scotland assert their identities and grab political control back from England, bit by bit, there is of course a tendency (encouraged by Welsh universities and research institutions) to flag up the "uniqueness" of the prehistoric heritage -- in exactly the same way as HHT used the bluestone transport debate to bolster English self-esteem after the First World War.    Sadly, we are never all that far away from political motives, even in what seems to be a rather esoteric debate about cultural assimilation, dispersal, parallel development and so forth........

Bluestones and sarsens

Phil Morgan has kindly sent me this excellent photo of some of the bluestones and sarsens at Stonehenge, and is happy for it to be published.  Thanks Phil.....  Click to enlarge.

One thing that strikes me yet again is that there is really no difference in colour between the bluestones and the grey stones!  But of course, when some (but not all) of the bluestones are broken or seen with fresh unweathered surfaces they do appear to be a bluish grey colour.

Phil's notes:

From Left to Right

Sarsen Circle Trilithons = 28, 29, 130, 30, 101, 1, 102, 2, 3, (5 + Bluestone 33);
Bluestone Circle = 46, 47, (48 fallen), 49, 31, (150 and 32 fallen), 61, (61a stump), 62, and 63.
Left foreground = Broken Sarsen Lintel 160b and 160c.

Incidentally, the stones of the Bluestone Circle, 46, 47, 49 and 31, listed above are the four orthostats referred to in paragraph 3 of Rob and Richard's paper on Craig Rhos-Y-Felin, 2011.

Lots of Earth Science -- why?

 The Gibbard - Ckark reconstruction of the limits of three different glaciations in Southern Britain.  These limits are crude and in some instances nonsensical in that they fail to take account of evidence on the ground or of glaciological principles.  Somehow or other, they have to be improved upon......

My faithful readers will have noticed that there has been a lot of earth science material posted on this blog in recent days -- and you might wonder what it is all doing on a site called "Stonehenge Thoughts."  Well, it's all part of my ongoing attempt to understand how glacier ice behaves in the SW quadrant of the British Isles -- and the nature of the "controls" that influence the course of events during the glacial episodes that we know about.  When, and how, did glacier ice extend into Somerset and possibly Wiltshire, during the Anglian or any other glacial episode?  We won't understand this until we know what the interactions are between Welsh ice and Irish Sea Ice -- and because the Anglian glaciation occurred around 450,000 years ago we don't have a lot of evidence to go on.  But if we can get a reasonable idea of what happened during the Devensian, we can use that as a good analogy or guide to understanding.

What I'm trying to do here is test the glacial hypothesis to destruction.  This is, sadly, not something that the archaeologists have done with the human transport hypothesis.......

Glacial deposits from the Early Devensian?

On looking through the records to see what there might be in the way of field evidence for an expanded Welsh Ice cap in the Early Devensian, the records are not easy to interpret.  Following the Ipswichian interglacial (O18 stage 5e) -- around 120,000 years ago, there was a long period of cool - cold - periglacial - glacial conditions, with lots of climatic oscillations, between 116,000 BP and 59,000 BP.  Some of these oscillations are given the O18 labels 5a - 5d, and then around 70,000 years ago came the sharply oscillating climate labelled as O18 stage 4.  That stage lasted for maybe 12,000 years -- see the earlier posts.

The coastal drift stratigraphy around Wales fits into this framework rather well -- with thick slope deposits (with much evidence of periglacial conditions and permafrost or frozen ground conditions now and then) sitting on top of the Ipswichian raised beach and beneath the glacial deposits assumed to date from the LGM of the late Devensian.  (See the stratigraphic columns for Pembrokeshire coastal sites in the earlier post.  Similar relationships are seen elsewhere in Wales.)

But then we have some rather mysterious exposures of tills that seem to pre-date the LGM -- at Criccieth,  Glanllybnnau,  Llanystumdwy,  Moranedd, and New Quay.  Do these tills date from an early expansion of ice from the Welsh Ice Cap which acted as a sort of precursor to the arrival of the Irish Sea Glacier?  (Big glaciers always take longer to react to climate change and then to build towards their maximum extent than smaller glaciers do.)  Or was there genuinely an interval between these two glacial "events" which coincided with the Middle Devensian interstadial episode conventionally labelled as O18 stage 3?

The "weathering layer" (assumed to have been formed during a warmer interlude)  seen above the Criccieth Till in the cliffs at Glanllynnau is overlain by fluvioglacial sands and gravels, with another till (called the Llanystumdwy Till) above that.  The weathered layer is a yellow-brown horizon on top of a blue-grey clay-rich till -- but we need much more evidence than a simple colour change before we can be sure that the top surface of the till has genuinely been affected by surface weathering under a warmer climate.  The upper surface of the Irish Sea till in Pembrokeshire is often decalcified and weathered in this way, simply because ground-water passes through overlying fluvioglacial deposits quite easily and then penetrates into the till beneath.  The colour change has nothing to do with surface exposure and nothing to do with a warmer climatic interlude -- it is simply a matter of chemistry.......

But on the other hand, in North Wales coastal sections  there are signs of solifluction features and also ice-wedge casts associated with this weathered horizon, and that has to mean there was an interval of non-glacial conditions before ice returned to deposit the upper layers in the sequence. 

This debate has some way to run.....

Arthur's Stone, Gower

On looking into the Paviland Moraine, I came across a number of references to Arthur's Stone, on the Gower -- a very large erratic of Namurian gritstone (I think) apparently derived from the North Crop of the Coalfield.  According to Prof David Bowen there are many other erratics from this source in the area of the Paviland Moraine, indicating that the ice that carried them came down from the north towards the South Wales coast.  It seems that this was one of the largest capstones in Wales, which at some stage has broken into two or more pieces......

Does anybody know anything more about this feature?  It looks like a rather crude Neolithic burial chamber.  Apparently there are a number of other burial mounds and later features (Bronze Age?) in the area.

Update:  According to the GCR for the Quaternary of Wales,  there are abundant Namurian "quartzite" erratics in and beyond the Paviland Moraine -- the key source is assumed to be Mynydd-y-garreg in Carmarthenshire.  Some boulders of this same rock type are found on the foreshore at Western Slade. 

The Early Devensian Welsh Ice Cap

I have been having a little discussion with Henry Patton about the likelihood of an Early Devensian Welsh Ice Cap growing sufficiently to extend beyond the present coastline.  Henry kindly sent me the above graph, which represents one of his early attempts to model the volume and extent of Welsh ice, plotted against the GISP2 oxygen isotope data for Greenland.

On the graph, the Last Glacial Maximum (LGM) shows up very clearly, with a very rapid ice expansion after a long period (10,000 years or so) of small-scale glacier expansion and contraction in the uplands.  the remarkable speed of ice cap expansion and then collapse is very impressive -- shown on this graph as falling in a period of around 5,000 years and centred on 24,000 yrs BP.  One might reasonably conclude that a long period of cold and snowy conditions is a prerequisite for ice expansion on a substantial scale.......  but the oxygen isotope data do not adequately explain the sudden increase in ice volumes and the sudden expansion of the glaciated area.  Other very important factors must have come into play......

As for the Early Devensian, we can assume that there was a Welsh Ice Cap in existence between 60,000 and 70,000 years BP, and maybe for  a few millennia before and after -- but it does not seem to have been more extensive than about 400 sq km (as compared with 30,000 sq km in the LGM).  What is interesting from the O18 graph is the huge climatic oscillations that seem to have occurred at this time, with temperatures apparently plummeting to a lower level than at any time during the LGM -- balanced by very rapid warming phases.  Maybe this sort of climatic instability was just not right for the gradual buildup of ice over the Welsh uplands..... 

Around 50,000 years ago there does seem to be evidence of a warmer period -- albeit with cold snaps now and then -- and this seems to me to accord with the evidence for the weathering of Early Devensian periglacial slope deposits around the coast.  Many other authors in other parts of the UK have brought forward evidence for one or more "Middle Devensian Interstadials."

To return to the Early Devensian Welsh Ice Cap, and the apparent mis-match between my field evidence from New Quay and the glacier modelling done by Henry, we still have to find out whether there are deficiencies in the model or misinterpretations of the field evidence.  Probably a bit of both......

Then we have the interesting question of the "Paviland Moraine" in western Gower, assumed by Prof David Bowen to be of Anglian age.  I'm not all that convinced by the dating of that feature -- could it be of Early (or even Late) Devensian age?  Watch this space.....