Some of the ideas discussed in this blog are published in my new book called "The Stonehenge Bluestones" -- available by post and through good bookshops everywhere. Bad bookshops might not have it....
To order, click

Wednesday, 29 August 2018

Is there a Devensian terminal moraine south of Caldey Island?

As all faithful blog readers know (I was tempted to write, in homage to my guru: "... as any fule kno....") I have been banging on about the Devensian glaciation of Caldey Island for ages.  Just stick "Caldey Island" into the search box and see what comes up.  But on looking through some old files I came across this map, showing the nature of the sediments on the floor of Carmarthen Bay.  Very interesting indeed!

As we can see, to the south of the island there is an extraordinary mixture of sediment types, ranging from mud to sandy mud to muddy sand to assorted types of sand and gravel and even "muddy sandy gravel" -- which sounds to me suspiciously like till..........  Is this all that is left of a long looped ridge that might have been a terminal moraine, marking the edge of the Late Devensian Irish Sea Ice Stream? There does not seem to be any trace of a physical feature on the sea bed today, but I like the thought......

The above map shows the reconstruction for the Bristol Channel landscape after the end of the Devensian Glaciation, during the late Upper Palaeolithic -- while the sea was starting to flood back in from the west.

If the ice edge was located somewhere around here, what of the other evidence?  Well, we have the apparent dilemma of till at the eastern end of the island, at Ballum's Bay, very close to one of the caves which has been investigated.  This is Nanna's Cave and Ogof-yr-Ychen, which I examined with Brother James and Mel Davies back in the good old days.

There are animal and human remains in the Caldey caves, mostly dating from between 20,000 and 30,000 years BP.  There are doubts about the accuracy of some of these old radiocarbon dates, relating to new protocols of correction or adjustment, but broadly these dates coincide with the peak of the Late Devensian glaciation.  So were all these wild animals prowling around the ice edge?  Were the caves overwhelmed by glacier ice at the peak of the glaciation?  Were human hunters in residence in these caves at the time that the ice advanced to its maximum extent and then started to retreat catastrophically?

We don't really know the answers to these questions, but maybe they are things we should now concentrate on..........

Paviland and its "RED LADY" (who was of course a man) also come into the frame, since Paviland Cave is not very far away, on the Gower Peninsula.

We need to piece together the geomorphological evidence with the evidence of Paleaolithic prehistory.  More thought needed......


PS.  3rd Sept 2018. 

I am more and more convinced that the Paviland Moraine in Gower is of Devensian age.  I have considered the evidence here:

Prof Dai Bowen argued that the moraine was of Anglian age.  Indeed, this dating was crucial in his denial that Irish Sea ice could have carried bluestone boulders to Stonehenge.  His reasoning was that if the Welsh Ice flowing southwards during the Anglian Glaciation skidded to a halt near the coast of Gower, Irish Sea ice could not have flowed across the Gower Peninsula towards Somerset and Wiltshire, and there can have been no mechanism for transporting the bluestones.

However, Prof DQB made a lot of dating mistakes in the course of his career, and I am convinced that this was one of them.  If the Paviland Moraine is Devensian it would be similar in age to the glacial deposits on Caldey -- and Anglian Irish Sea Ice could well have passed across this area on its way to Stonehenge.

Things are knitting together in a variety of ways, some of which are unexpected.......

1 comment:

TonyH said...

This link you have drawn our attention to with the "Paviland Lady" of the Gower, and the early prehistoric history of parts of Caldey Island, might even,....Heaven knows!..... cause some of the less prejudiced archaeologists who work in SW Wales to actually start to CONSIDER geomorphological features like the Devensian Ice Age, and the possibility of a terminal moraine. THAT would be a real turn up for the books (but, unfortunately, not for any books bearing the Authorship 'Michael Parker Pearson et al'!!