Pages

Friday, 28 March 2014

Beyond Belief -- Stonehenge


Julian Thomas, trotting out the same old stuff.....

http://www.bbc.co.uk/programmes/b03y0lcl

A 30-minute programme investigating the spiritual significance of Stonehenge.  Presented: Ernie Rea -- guests Prof Ronald Hutton, Julian Thomas and Frank Summers. 

Interesting conversation, but the usual nonsense from Julian Thomas about the "periglacial runnels" being the reason for the location of Stonehenge where it is, and a rather arrogant dismissal of the glacial transport theory without any explantion about why it is "out of fashion."   Perhaps, if he had been prepared to be a bit more honest, Julian might have admitted that it is science that is out of fashion, because the present generation of archaeologists prefers fantasy.......

Anyway, the prog is available for listening via the BBC web site (link above).

Thursday, 27 March 2014

Those Neolithic houses


This pic was in the press this week -- one of the Neolithic houses being built near the Stonehenge Visitor Centre -- and based, by all accounts, on the remains at Durrington Walls.

I note the rounded corners -- I thought Neolithic houses were rectangular?  

Very interesting -- no doubt more info will emerge.  I really like the ladders, the hard hats and the hi-vis jackets......

Link resource:
Follow their progress here: http://neolithichouses.wordpress.com/
English Heritage Link: http://www.english-heritage.org.uk/daysout/properties/stonehenge/discover/neolithic-houses

Follow the project and progress on Twitter:

https://twitter.com/NeolithicHouses

https://twitter.com/Eh_stonehenge

https://twitter.com/ST0NEHENGE

Lennoxtown Erratic Train


I was digging into an old geomorphology text by Brian Sissons when I came across this splendid example of an erratic train.  It's called " the Lennoxtown Boulder train" and it is located in the central valley of Scotland, west of the Firth of Forth.  The discontinuous train of boulders comes from a very distinctive (and small) igneous outcrop near Lennoxtown -- in the early 1900's this rock was called "essexite" but is now probably called something quite different........

The train of boulders is at first very narrow -- just a couple of kilometres -- as it curves round the southern slopes of the Kilsyth hills.  Then it widens gradually to a width of c 6 km as it runs eastwards along the Firth of Forth.  The total length of the boulder train is about 60 km.  In the western part the boulders are quite frequent, but after that they are discontinuous, and the map is based upon many scattered occurrences logged by Peach and Horne in 1909.

If you look at the streamlines you can see that two ice streams converged in this neighbourhood and then flowed eastwards, with southern and northern ice streams in parallel -- and with the boulder train squeezed between the two.  This is exactly the mechanism proposed by Lionel Jackson and myself some years ago, in our article in EARTH magazine:

http://www.earthmagazine.org/article/stonehenges-mysterious-stones

In discussing the Foothills Erratic Train and the bluestone transport hypothesis, we wrote:

To gain an appreciation for how the convergence of two ice sheets can create a virtual conveyor belt for the transport of erratics, we have to travel to the foothills of the Rocky Mountains in Alberta, Canada.

This amazing trail of pebbly quartzite erratics, called the Foothills Erratics Train, can be traced from the forested Macleod River region in Alberta to the United States-Canada border in western Montana 580 kilometers southward. Over most of its length, the trail is only a few kilometers wide, narrowing to less than one kilometer in some areas. Individual erratics range in size from less than a cubic meter to one rock that has the mass of 10 Stonehenges.

The source of the rocks is in the Great Divide in Jasper National Park. The rocks appear to have fallen onto valley glaciers, which carried them into the Foothills Erratics Train via glaciers in the Athabasca River Valley. Normally, mountain glaciers would spread into so-called piedmont lobes where they leave the mountains and spill out onto the plains, dispersing the rocks that they carry in a fan shape. Indeed, this occurred farther south in the American Rockies during the last glacial maximum about 20,000 years ago. However, in the case of glaciers flowing out of the Canadian Rockies, they encountered the western margin of the vast Laurentide Ice Sheet, which was diverted southeastward by the high topography of the range’s foothills. The Athabasca Valley Glacier carrying the erratics became a tributary to the Laurentide Ice Sheet and flowed southeastward with it.
This parallel flow of two ice streams, maintained by pressure from both sides, is quite analogous to the situation in Wales. As the two ice streams came together, they would have maintained a contact zone as the ice approached its easternmost limit in England. It is reasonable to believe that the contact zone of ice carrying bluestone erratics — and maybe some other stones from South Wales — would have resulted in an erratics train rather than a fan.

Unlike the blocks of the Foothills Erratics Train that fell onto the surface of the glacier from cliffs in the Rocky Mountains, the bluestone erratics train would have been plucked from outcrops and initially transported within the ice. However, once entrained, the blocks would have been transported relatively high within the body of the glacier (see sidebar, p. 39). By using the Canadian Rockies analogy, it suddenly becomes clear how the boulders of Stonehenge could have been deposited in a trail across southwestern England — and thus would have been easy pickings for Neolithic Britons.

Wednesday, 26 March 2014

Ten Bluestone Questions



 These are some of the questions I raised in my talk last night -- which do not have satisfactory answers from the archaeologists.  Still waiting.......

Ten Bluestone Questions for the Archaeologists:

1.  If the sarsens and the bluestones were carefully selected for use at Stonehenge, how come that there are at least 30 different rock types represented in the Stonehenge "bluestone assemblage"? (including fragments, orthostats, stumps, mauls and hammerstones)

2.  If the bluestones were really "the stones of the ancestors", carried to Stonehenge for ritual purposes, how come that all of the stones are from the west, with no bluestone orthostats at all from the north, east or south?

3.  If the spotted dolerites and foliated rhyolites were "valued" in some way, how come that they are not used preferentially in stone settings in West Wales?

4.  And if Rhosyfelin really did have a Neolithic orthostat quarry in it, how come that there is not one cromlech or standing stone setting in Pembrokeshire that uses stone from this quarry?

5.  If the West Wales Neolithic tribes were so clever at long-distance stone transport, how come that ALL of the cromlechs and standing stone settings in Pembrokeshire simply involve the use of stones collected in the immediate vicinity?

6.  How come there is no evidence anywhere in the UK of systematic long-distance haulage of orthostats intended for use in a large stone setting?

7.  If the creation of Stonehenge was dependent upon a successful "stone hauling culture" using some suitable technologies, how come there is no evidence (as per the innovation diffusion model) of a developing culture, a climax, and a decline -- from a wide variety of sites other than Stonehenge?

8.  If it is now accepted that the sarsens were probably collected up from the vicinity of Stonehenge, why should the builders of the monument have done anything different when it came to the smaller bluestones?

9.  If the bluestones were revered in some way, and carried as "ancestor figures",  how come they are not more standardised in shape, size and lithology? (They are immensely variable and come from a very wide variety of locations.)

10.  If there really was a strong cultural or "political" link between Stonehenge and West Wales, where is the evidence to support the idea?

Talk on "The Bluestone Wars"



Well, that was fun!  My talk at Moylgrove last night was very well attended -- not many locals (they have heard me before!) but quite a few people from far afield -- presumably including some archaeologists and some who have been involved in digging at Rhosyfelin.  One or two people were taking copious notes..........

I thought it would be fun to give my talk the title "The Bluestone Wars" -- homing in on the amiable conflict between the two archaeological tribes (one led by Chief MPP and the other by Chiefs GW and TD) and the geomorphology tribe of which I count myself a proud member.    The evening was chaired by Robert Anthony, who has been involved in the Rhosyfelin digs as a volunteer, and who knows all sides of the argument.  There were some good questions from the floor, and it was nice to see a lot of involvement from the audience.  I managed to get all the way through my talk without using the word "quarry" once, which was only right and proper. 

Of course I got a few questions about Rhosyfelin, and I hope the questioners left the hall rather better informed than they had been when they entered.  It was pretty clear that some people have just accepted everything which MPP said at his talk in September 2013 without applying any critical appraisals of their own -- it's rather sad to see how gullible some people are!  But I suppose it's understandable -- people have other things in life that take up rather more of their time, and unless one has visited the site it's difficult to form views of one's own.

Saturday, 22 March 2014

Tim's Long Barrow


The BBC web site has a great photo portrait of our friend Tim Daw's wonderful project -- a long barrow which will be available for people who wish to have their ashes stored somewhere rather pleasant long after they are dead and almost gone.  Apparently the spaces are already starting to sell.......


Well, it's not so different from the custom of storing coffins and corpses on little shelves  in cemeteries in the Canary Islands, where the ground is often too stony for burials to take place.  See photo below -- a cemetery on La Gomera.

http://www.bbc.co.uk/news/uk-england-wiltshire-26683268


Fifty Shades of Blue




You may be interested to see this photo album which I have assembled via my Facebook Page.  It's a collection of stunning photos (hardly any of them are mine!) portraying glaciers, icebergs and other things made of ice.  Enjoy!!


https://www.facebook.com/brian.john.526/media_set?set=a.804590736222961.1073741836.100000161271278&type=3

Periglacial stripes - East Greenland


I came across this very spectacular photo of periglacial stripes near Hurry Inlet, Jameson Land, East Greenland.

The vegetated stripes are the rills, mostly about 1 m wide.  This is where moisture levels are higher, enabling plants to survive.  On the rare occasions when it rains, water runs down these rills, maybe helping to keep them incised beneath the level of the ridges.

The ridges are kept barren because this is where periglacial processes are going on, with frost-heave rearranging things and making it difficult for plants to get established.  Most ridges are c 1m - 2m across.

Note that these periglacial stripes run directly down the maximum  available slope.

Friday, 21 March 2014

Erratic delight


This is a photo of huge banks of moraine beyond the edge of a valley glacier near Sermilik Fjord in East Greenland.  I was idly looking at it when I realised it was one of the most splendid erratic photos I have ever seen.  Enlarge the photo with a click, to see what I mean........

I you look at the big bank of moraine in the centre of the photo, look just to the right of centre, and you will see a huge brown boulder embedded in the rubble.  Where did it come from?  Look again at the photo, in the middle distance, and you will see that whereas most of the rocks hereabouts are grey-coloured, there is a distinct cluster of hillocks where the rocks are bright brown in colour.  The big erratic boulder in question has clearly come from an outcrop of that brown rock further up the valley.....

The interesting thing is that almost all of the other rocks in this particular patch of moraine are grey-coloured.  Did the boulder fall onto the ice from the valley side, or was it entrained from an outcrop beneath the glacier surface by a process of glacial erosion?  I would never say that what has been going on here is random, because everything is in nature is explicable if we have the right fieldwork at our disposal, which here (sadly) we don't......

But this does illustrate a point I have been trying to make repeatedly on this blog.  Erratics do not always exist in continuous trains running from source points to final resting places.  And sometimes they can be found in glorious isolation, in quite unexpected places.....


Glacial trough, Sermilik Fjord, East Greenland


There are some splendid glacial features here -- this is a photo of a subsidiary trough or glaciated valley coming out from the mountains into a broader tough (foreground) which is now largely ice-free.  The location -- near Sermilik Fjord in East Greenland.

The black lines show:

1.  The break between the jagged peaks on the skyline, which are fashioned above all else by periglacial processes (marked A) and the ice-moulded rock surfaces below (marked C), which have been dramatically fashioned by glacial erosion at a time when the glacier was thicker and more powerful.

2.  The crest of a splendid ridge of terminal moraine, which runs out into the valley in the foreground, marking the position of a stillstand or protracted position of the glacier front.

The glacier itself (marked B) has now shrunk considerably in size.
In the foreground (marked E) there are much older morainic deposits, now for the most part covered with vegetation, and with a litter of erratic boulders on the ground surface.

If you click on the photos you can enlarge them to inspect all the features in greater detail......  you should be able to click back and forth between the clean photo and the annotated one.

Tuesday, 18 March 2014

The Shebbear Erratic


I came across this fine photo of the Shebbear Erratic, which lies on the village green.  Shebbear is in Devon, about 20 km inland from the west coast and about 15 km from the sea in Bideford Bay.

I've not seen an accurate description of the stone's geology, and it is variously described as being made of quartz (highly unlikely) or of a pinkish granite -- whatever it is, it is not local, and is therefore an erratic.

According to legend, it is the "Devil's Stone"  -- and it has to be turned over at 8 pm on November 5th every year, in order to keep the Devil at bay.  Hence the ceremony going on in the photo.

It's interesting that this erratic (weighing about a tonne) is not far from an area on the Devon coast where glacial erratics are abundant -- the big erratics at Croyde and Saunton are of course very famous. (Two of them are shown below.)  There are nine of them in accessible places along the shoreline, trapped beneath later deposits.  There is also till at Fremington Quay and other localities nearby.  Traditionally, geomorphologists prefer to think that the erratics were emplaced by floating ice -- a theory which I do not accept, for reasons enumerated in this blog on a number of previous occasions.  On the other hand, it's accepted that the till deposits were emplaced by Irish Sea ice pressing against the coastline but not progressing far inland.  We know that the Irish Sea Glacier DID progress far inland across the Somerset Levels, and to me the presence of the Shebbear Erratic indicates that the ice was thick enough, and with enough force behind it, to push well inland across the west Devon countryside.......

Big glacial erratics near Croyde in Devon

For other records of "stray stones" see this post:
http://brian-mountainman.blogspot.co.uk/2011/11/stray-stones-in-south-west-england.html




Wednesday, 12 March 2014

Classic Pembrokeshire Pleistocene locations (1)

 Ancient till site, Lydstep Headland, South Pembrokeshire. The till (beneath the overhang) is solidly cemented (this is on Carboniferous Limestone) and may be Anglian or older

Raised beach (rock cut) platform cut into a Carbonbiferous Limestone cliff in Broad Haven (South) Bay, South Pembrokeshire

Close-up view of the same platform

Probable pre-glacial shoreline and old marine cliffline, with a spur almost cut off by an arcuate humped channel called Cwm Mawr -- Dinas, North Pembrokeshire

Close-up of the Cwm Mawr Subglacial Meltwater Channel, Dinas.  This feature may be composite in age, dating from the Anglian Glaciation and maybe used again during the Devensian

Rock-cut raised beach platform (age unknown) with probably Ipswichian interglacial beach deposits resting on it, and Devensian periglacial and glacial deposits above.  Poppit, near St Dogmaels in the Teifi estuary.

Apologies for the colours in these pictures -- they are scanned from some very old slides from my collection, and colour rendering is somewhat hit and miss......

Sunday, 9 March 2014

Video gets over 35,000 views



I noticed today that my subversive video called "The Stonehenge Conspiracy" has now had 35,000 views  -- that's probably not many views compared with some of the "viral" YouTube videos about that venerable pile of stones, but it's nice to know that some people are interested in conspiracies and like to see the orthodox view of things seriously questioned.......

http://www.youtube.com/watch?v=-f4c3F9iEaY

Thursday, 6 March 2014

Newgale Submerged Forest - 2014 exposures

 



Been over to Newgale today, to inspect the exposures of the submerged forest.  Very interesting.  It was raining and blowing, but at least I managed to get some photos......

The top three photos are of the peat beds which are normally covered by sand -- the beach is now about 2m lower than it was, following the winter storms.  As we can see, some of the peat bed exposures are coherent, and other sections are being broken up into rills by water streaming up and down the beach.  Most of the pebbles you can see around these rills have been dragged down from the storm beach and dumped here to replace sediments that have been destroyed. 

The lower two photos show some of the woodland remains.  The exposures here are very different from those at Ynyslas, where actual tree stumps are exposed at the moment -- here we just get occasional traces of root systems, and a lot of debris embedded in the peat.  There are wood fragments everywhere, especially on the southern part of the beach, near the southern cafe and caravan park.  The biggest piece of wood which I found was a long tree trunk about 6m long; and the thickest was about 1m across.  So we are talking about a woodland of quite mature trees.

The stratigraphy is much more complex than I had imagined.  I hope some bright young thing from one of the universities has been looking at it, and making an accurate record......

In Newport the peat bed and submerged forest lies directly on till and frost-shattered (periglacial) debris -- but here, in a much more open environment, the peat bed is quite thin -- mostly less than 50cms thick -- and is resting on a variety of different materials -- sandy gravelly material in some places and actually on beach pebbles in other places.  These beach pebbles are loose and unconsolidated, but in a few places there are exposures of solidly concreted beach and river gravels which may even be interglacial in age.  All very complicated.....


 The peat beds in this area are quite thin, and are underlain by sandy and gravelly 
unconsolidated material.


Here the peat bed is also thin -- just a few cm thick -- and is underlain by unconsolidated storm beach material.  Was this material thrown over an advancing storm beach ridge into the boggy area beyond the ridge, in exactly the same fashion as we have seen in recent weeks when the storm beach advanced across the road?


A patch of solidly cemented beach or river gravel exposed through the sand.  One cannot see the precise stratigraphic relationship with the peat beds.   Is this material the same age as the cemented interglacial raised beaches that we see in other parts of Pembrokeshire?


Another much larger exposure of this cemented beach - river gravel material, standing up as a pedestal.

In trying to work out what has happened here, my best bet is as follows.  There are some very old deposits here -- maybe dating from the last interglacial.  These materials must have been overridden during the Devensian ice advance of the Irish Sea Glacier, but we see no signs of till or periglacial materials out here in the open bay.  Peat beds and woodland then started to form after the ice retreat, when the coastline was far out to the west. So some peat beds might be more than 7,000 years old.  I think these peat beds and the forest might have survived for at least 5,000 years -- this could be established by pollen analysis and examination of the tree species represented.  The sea rose inexorably, and as it did so it drove a storm beach ridge eastwards, covering the old peaty / woodland area bit by bit, leaving it submerged beneath pebbles and sand.  Within the last 2,000 years or so the eastwards advance of the storm beach ridge has slowed down as sea level has stabilised, but we know that it has continued because historical records show that there have been at least two other inns at Newgale, each of them in the area now submerged beneath the beach.  The current Duke of Edinburgh Inn, alongside the road that has been blocked by pebbles several times this winter, is equally vulnerable -- and one wonders how long it will survive!

The interbedding of storm beach pebbles and peat beds suggests to me individual storm events in which waves have overtopped the ridge, flinging pebbles onto the peaty boggy area on the landward side -- then followed by more peat formation, when "normal" waterlogged or lagoonal conditions returned.

So it is quite possible that the peat beds are of all sorts of ages, with some of them shown in the photos above no older than a few centuries........







Wednesday, 5 March 2014

Newgale peat beds


Brilliant photos of the peat bed exposures at Newgale keep on coming ---- I found these yesterday on Twitter!  Thought they were worth sharing.

Westdale Bay -- close to the Devensian ice edge?


These 3 photos are from Westdale Bay, not far from the mouth of Milford Haven and quite close to the village of Dale.  The deposits there are seriously confusing. 

If you look at the top photo, taken at least 50 years ago when I was young and innocent,  you can see clearly the banded nature of the sediments high in the sequence -- suggesting water deposition or maybe flowage of saturated sediments very close to an ice edge.

But the ice edge at the maximum extent of the Devensian wasn't here -- it was, according to my interpretation of the evidence, further to the east across the peninsula, where a wonderful kame terrace was once exposed in all its glory when gravel working was going on there.  This was at Mullock Bridge.  That having been said, at the base of the sequence there is certainly an excellent exposure of Irish Sea till, coloured reddish because the rocks hereabouts are ORS.  This layer is shown in the middle photo.

The bigger problem is associated with the lower photo, showing a deposit from higher in the sequence -- I thought at first that it showed a finer-grained till, but now I'm not sure.  It looks more like a soliflucted or rearranged till, composed mostly of rather angular fragments of locally derived sandstones.

Must get back there one day and have a look...... so little time, and so much to do...

Daily Mail in on the act.....



Thanks to Rob for drawing this earth-shattering news to my attention.  Now the Daily Mail is in on the act, with the headline:

Is Stonehenge just a gigantic xylophone? Researchers tap landmark's bluestones and record them 'singing'  

http://www.dailymail.co.uk/sciencetech/article-2573459/Is-Stonehenge-just-gigantic-xylophone-Study-sound-rocks-make-hit-finds-bluestones-make-landmark-sing-struck.html

Royal College of Art researchers say that Preseli hills bluestones sound like no others tested from across the country
Sonic qualities may explain why prehistoric Britain's took them 200 miles to Salisbury to build Stonehenge 4,000 years ago

-----------------------------------

Well, who cares?  I'm glad the Mail managed to extract some humour out of the story, and it makes a change from all that doom and gloom......

Tuesday, 4 March 2014

Treasure Trove?





Now here's an interesting thing -- I got a message from a lady who enclosed two photos with her email.  This rather interesting object has been revealed on a certain beach, in a secret location, as a result of the recent storms.

Has anybody seen anything similar before?  The romantic side of me thinks it might be a chest full of gold bullion, lost when the Spanish Armada was blown around the west coasts of Britain, with many of the vessels getting shipwrecked.........  It certainly doesn't look like something made by our sturdy Mesolithic ancestors, and lost in the submerged forest. 


Monday, 3 March 2014

Stonehenge rock concert fails to stir the fans.....


 Paul Devereux, who is the man behind the "ringing rocks" hypothesis.

 Paul trying to convince the reporter that the "one that got away" at Carn Meini is a ringing rock, by making some dull thuds with his little hammerstone.....

 Tim Darvill (centre) doing his best to be non-committal....

 George Nash, who managed (sort of) to find something encouraging to say.... no doubt after listening to lots of dull thuds coming from the Stonehenge standing stones.

Go to the 18 min mark to watch this rather excruciating demonstration of how people can make a lot of fuss out of nothing at all.  All rather embarrassing really......  Tim Darvill and George Nash put a brave face on it, but probably wished they had been somewhere else......

I hope my valuable taxpayers money was not used in this fantastical exercise -- but I suspect it was.......

Even the reporter looked embarrassed.

http://www.bbc.co.uk/iplayer/episode/b03x0tx1/Inside_Out_West_03_03_2014/

Re-classification of the Palaeolithic


With no particular relevance to anything, I just thought my faithful readers would enjoy this.......

Saturday, 1 March 2014

Rearranged Talk -- March 25th



The talk I should have given in Moylgrove Village Hall on 3rd December, but had to cancel because I was down with some nasty flu bug, has been rearranged for 7.30 on Tuesday 25th March.

Title:  "Stonehenge, Pembrokeshire and the Ice Age."

Everybody welcome -- and I shall try to avoid using the word "quarry"...........