Westdale Bay and the meltwater channel

This is a fabulous image taken by Paul Davies and published on the Pembrokeshire Geology Group Facebook page.  Click to enlarge.

In the background we can see the Milford Haven waterway.  The valley which we can see cutting across the neck of Dale Peninsula is almost certainly a meltwater channel of considerable age.  It may well be the same age (Anglian Glaciation?) as the other big subglacial channels of north Pembrokeshire. It is rather a spectacular feature -- I have never seen it so clearly illustrated in a photo.  The channel runs along the line of the very important Ritec Fault, which "guides" many major features, including the alignment of Milford Haven itself.  The brecciated zone which is often associated with major faulting is easily picket out by fluvial and glacial processes over a very long period of time.

The "plug" of Pleistocene deposits which partly fills the valley is very obvious -- see other posts on this by putting "Westdale"into the search box. I think these deposits are of Devensian age, around 20,000 years old.

Some researchers have suggested that the Dale Peninsula was once an island, and that a narrow strait ran along the course of this valley.  That's possible, but I am not sure the valley is deep enough for that.  I would like to see some evidence of old sea cliffs and maybe beach deposits well into the valley and beneath the glacial / periglacial sediments.  Such deposits could only be found through drilling..............

For the moment, I prefer to think of the valley as a Pleistocene deepening of an old fault-guided river valley.  As I have indicated elsewhere, there are other signs of meltwater erosion in this part of Pembrokeshire, and of course the classic kame terrace not far away, at Mullock Bridge.

Added 1st Sept 2019.  Here is another fine image of the sediment-filled through valley, with Westdale Bay on the right and Dale Village on the left at the far end of the channel.

Bluestone pillars or boulders?

I have no idea (well, actually I do) why EH and almost everybody else insists on portraying the bluestone circle at Stonehenge as if it was a circle of slim and elegant pillars.  The evidence for that is extremely scanty, as I keep on saying whenever I am in party pooper mode.

The pic above is from the EH display at the Stonehenge Visitor Centre.

Actually, as we now know from the excellent "Stones of Stonehenge" project (the Simon Banton one, not the MPP one), the bluestones were a mottley collection of heavily abraded slabs, stumps and boulders -- as fine a collection of glacial erratics as you are ever likely to find anywhere.

http://www.stonesofstonehenge.org.uk/search/label/Bluestone 

I accept that elongated pillars of spotted delerite were preferentially used in the final setting of stones in the bluestone horseshoe.

If you want a more accurate representation of what the bluestone circle might have looked like (forget for a moment about the sarsens) this pic from Moel Ty Uchaf is a rather nice guide.

Both sides of the argument....

This is the English-language page from the Pembs Coast National Park's tourist newspaper which deals with the bluestone quarrying debate.  I have been badgering them for years to stop trotting out the fantasies of the senior archaeologists and to accept that there is a debate going on -- in which there is room for some science too!  Anyway, to their credit they responded, and invited Geoff Wainwright and me to contribute short bits of text. This is the result.  Sadly, Geoff died before this edition of "Coast to Coast" was published.

Yet more BBC nonsense on Stonehenge

No sooner have I finished one gripe about the BBC  than along comes another absurd non-story from the corporation, and yet another piece of Stonehenge mythologisation.  Will it never end?

http://www.bbc.com/travel/story/20170713-why-stonehenge-was-built

This time, in addition to the usual guff about Stonehenge breakthroughs and new exciting discoveries, Vince Gaffney and Mike Parker Pearson are the featured archaeologists. There is nothing new -- this is just old info, regurgitated for no particular reason.  Somebody presumably needed to make a programme about Stonehenge.   In the midst of all the purple prose, Vince Gaffney makes one rather nice statement arising out of the fiasco surrounding the stones that never were, at Durrington Walls:  “Following this survey, we know not only where things are but where they aren’t as well.”  Quite so.

MPP's standard bluestone story is repeated here yet again.  Quote:  Parker Pearson suggests that the Welsh bluestones were the first to be put in place at Stonehenge, and that it was the monument that they came from that was important. The stones would have been considered to be ancestral symbols of western Britons, he said, and “bringing them to Salisbury Plain was an act of unification of the two main Neolithic peoples of southern Britain.”  Even today, the Preseli hills are dotted with dolmens (ancient tombs). “The density of dolmens reveals that this was an important region (both politically and spiritually) some 700 years before Stonehenge,” Parker Pearson said, making it “possibly a leading territory within western Britain in the centuries before 3000 BC.”  But even if we agree with the theory that bringing the stones from Wales was a symbolic and even political, act, it presents another mystery: how did prehistoric Britons move those huge stones?
Some suggest that people didn’t move the stones at all, and that instead, glaciers transported the stones across southern Britain. But the finding of two ancient stone quarries in Preseli ended that debate for the most part.  Scientists also have experimented with ideas of how to transport the large stones 160 miles (260km) from Wales. According to Parker Pearson, they discovered that moving small megaliths like the bluestones, which mostly weighed 2 tons or less, was not actually that difficult – even with just dragging the stone on a sledge."

Leaving aside the "ancient stone quarries" for the moment, I wonder why MPP needs to mislead gullible reporters (and a gullible TV public) by giving false information about the density of dolmens in the Preseli Hills?  It is quite clear from the maps of prehistoric features in West Wales (see the Darvill /Wainwright chapter in the Pembs County History) that dolmens are NOT that abundant in the Preseli Hills, and that the density of these and related features is much greater in other parts of Pembrokeshire.   What the hell -- when there is a good story to tell, who cares about the truth?

And moving bluestone monoliths is not that difficult?   Sure it's not, in a London Park on a sunny day with lots of willing students to pull a sledge across a nice flat lawn......

Everything is twisted -- and these senior archaeologists will continue to twist things for as long as they are allowed to get away with it.

More on Stonehenge mental health healing project

I hadn't realised it, but there was a BBC Radio 4 "Open Country" broadcast back in April, which can still be listened to here:

http://www.bbc.co.uk/programmes/b08md98n

One has to feel positive about the effects of the experience on the participants who needed help.  And it is great to hear the views of those who previously felt isolated and fearful of social contacts.  Parts of the 24 min programme are genuinely moving, and the "bonding" of those who took part in the 10 week courses in the Stonehenge landscape was clearly quite substantial.  The programme concentrated on the last day of the course as experienced by one of the groups -- in which the participants were granted access to the centre of the stone circle, where they shouted, sang, cheered and played musical instruments.

Tim Darvill was clearly involved in the course at intervals, and good for him for giving his time so enthusiastically.

And yet ... and yet..... having listened to the programme and having quite positive personal views about the project itself, I still have this rather deep sense of unease.  Tim, when interviewed, gave his familiar version of the Stonehenge bluestone transport story, and talked of Stonehenge as a centre of healing. No ifs, buts or maybes -- this, he said, was the way it was, and because he is such a senior academic we can be pretty sure that those who took part in the course were deeply grateful for being told "the truth" by an experienced academic.  Did Tim explain that his theory about "the healing stones" is actually hotly disputed, and that there are other theories too, some of which have rather more substance to them?  One doubts it....... that would probably have made life too complex for the vulnerable participants to cope with.

So I am now even more convinced that this is yet another episode in the long history of Stonehenge mythologisation.  It's also a nice opportunity for Prof TD to develop the strength of his own "bluestone hospital" theory by saying "Just look what happened to all those unfortunate people who needed help when they came into contact with the stones!  They all felt as if they were healed by the experience!"  I just hope he will never say that -- and my feeling about the BBC interviews is that they showed the immense value of social interaction and "bonding" within a group of vulnerable people brought together regularly over a 10-week period in an ancient landscape, in all weathers, with very careful and sensitive guidance from the project leaders.

The Bristol Channel Glaciations

There's a very interesting new publication by Gibbard, Hughes and Rolfe which provides fascinating new material on the glaciations of the Bristol Channel - Severn Estuary region.  The authors refer to at least three glacial phases, at least one of which involved a substantial ice incursion into Somerset. Archaeologists, please take note........

Here is the citation:

New insights into the Quaternary evolution of the Bristol Channel, UK
PHILIP L. GIBBARD, PHILIP D. HUGHES and CHRISTOPHER J. ROLFE
JOURNAL OF QUATERNARY SCIENCE (2017)
ISSN 0267-8179.
DOI: 10.1002/jqs.2951
https://www.researchgate.net/publication/318198065

ABSTRACT:
A synthesis of new publically available borehole and bathymetric data, combined with a wealth of
other existing disparate data sources, reveals new insights into the Quaternary history of the Bristol Channel area.  Sediment boreholes throughout the Bristol Channel confirm the area was glaciated in the Pleistocene. Till is present below marine deposits and, in some areas, is visible morphologically as submerged moraines. In the central and eastern Bristol Channel the submerged valley course of the palaeo-Severn is very clear in new high-resolution bathymetric surveys. This former river course and associated tributaries cross-cut through glacial sediments in the Bristol Channel. At least three phases of glaciation are recorded in the Bristol Channel, one related to the southern limits of a Late Devensian Substage ( Marine Isotope Stage (MIS) 2) Welsh Ice Cap which reached into Swansea
Bay, an earlier Devensian (MIS 4–3) glaciation associated with Irish Sea ice, and another older glaciation that is associated with ice that filled the entire outer and central Bristol Channel. The age of the older Bristol Channel glaciation is still open, although it pre-dates the Devensian (Late Pleistocene) and must date to the Middle Pleistocene. It is therefore evident that Pleistocene glacial and fluvial activity, combined with subsequent postglacia sea transgression, directly account for current morphometries of the Bristol Channel and Severn Estuary, and the current geography of the SW British Isles.

 =================

I recommend a reading of this article -- it's written in good plain English, mercifully free of convoluted techno-speak.  Its key findings are interesting, and the authors agree that there was a substantial early glaciation (which has to the the Anglian Glaciation, around 450,000 yrs BP) during which Irish Sea Ice filled the Bristol Channel and the Severn Estuary and flowed into Somerset.  How far the ice travelled to the east is a matter of debate, and so a dashed line is used on their key interpretive map:

 I think the authors could have been a bit braver with this "early glaciation" line, and as suggested many times on this blog, I think the ice at the time of the GBG pressed against the coasts of Devon and Cornwall and pushed south of the Isles of Scilly.

The lobe of ice pushing in over Lundy Island in the early / middle Devensian is to my mind not all that well supported, and is too dependent for comfort upon some cosmogenic dates that might well need correcting. 

I'm also not very keen on the Late Devensian line, shown running south from Milford Haven to the Scilly Isles.  I don't think this is well supported sedimentologically, and it doesn't make glaciological sense either.  I think Late Devensian ice pressed well into the Bristol Channel embayment, and I remain convinced that some of the "pre-Devensian sediments" shown on the map may well prove to be Late Devensian too.

All good fun.  The debate will continue -- but this paper is a welcome addition to the literature.

The first use of exotic stones on Salisbury Plain

When were bluestones (ie exotic or erratic stones) first used in the Stonehenge landscape?  I asked this question a couple of years ago, and we had a useful discussion following the post.  It can be found here:

https://brian-mountainman.blogspot.se/2015/09/when-were-bluestones-first-used-at.html

This is actually one of the most important questions if we are ever to sort out the question of bluestone transport and use.  The question is still not adequately answered, even though there are now abundant radiocarbon dates associated with stone settings.

As I understand it, there are currently two schools of thought among archaeologists:

1.  According to Mike Parker Pearson bluestones were first placed in the Aubrey Holes at Stonehenge, which means that they were present in the Stonehenge landscape around 3,000 BC or 5,000 BP.  This "early date" might be supported by the presence of fragments of bluestone at the western end of the Cursus -- which was by all accounts earlier than the main phase of building at Stonehenge.

2.  According to Tim Darvill and Geoffrey Wainwright, the bluestones were imported from Wales around 2,500 BC -- 500 years later than the MPP proposal.  That late date is presumably supported if one is sceptical about bluestones in the Aubrey Holes -- and it must be agreed that the evidence of "crushed chalk" at the bottom of one Aubrey Hole is not exactly convincing evidence for a bluestone circle.  Some versions of the story have it that the bluestones were not used until 2,300 BC --  when there was a "new bluestone setting" using stones freshly imported, or else used again following a period of storage in the local bluestone depot.

As I have suggested on this blog, Prof MPP appears to be pushing the "first use" date back and back towards the Early Neolithic, partly in order to accommodate those very inconvenient radiocarbon dates from Rhosyfelin, and partly to tie things in with the "megalithic" phase in West Wales.  This would also of course be supported if the Boles Barrow bluestone really did come from a long barrow that appears to have been constructed around 3,500 BC. (The long barrow building phase on Salisbury Plain is assumed to have been at around the same time as the cromlech / dolmen phase in West Wales.) Also, spotted dolerite ("Preselite") axes apparently dating from the period 4,000 BC - 3,000 BC appear (not very often) in the Stonehenge landscape, and one explanation by Olwen Williams-Thorpe is that they were made close to Stonehenge from in situ erratic material.  That is in my view more likely than the "trading" hypothesis.......

Of course, the earlier the first established use of bluestones can be shown to be, the greater the likelihood that the bluestone erratics were simply used more or less where they were found.  No need for human transport; glacial transport is the obvious and simple explanation.  That's because:

(a) the technology for bluestone transport would simply not have been available before 3,000 BC;
(b) if bluestones were used right at the beginning of the "stone phase" at Stonehenge, that suggests they were collected indiscriminately along with sarsens in the immediate vicinity;
(c) it is vanishingly unlikely that "the bluestone expeditions" would have occurred before the Salisbury Plain tribes had accumulated any skill in the setting of stones into the ground.

As I have said many times before, in the period 3,800 - 3,000 BC, in West Wales, where stones were being used in megalithic structures, those stones were ALWAYS used where found.  No matter what fantasising our archaeological brothers may indulge in, there is no reason why a different set of rules should have applied in the Stonehenge landscape.  Avebury seems to confirm that -- only sarsens were available, and only sarsens were used.