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

Saturday, 11 January 2014

St Govan's Chapel

While digging around among my old slides, I found this one.  Thought I'd share it, for no other reason than that it is a gorgeous little chapel in a magical spot!  It's at St Govan's, a little way along the South Pembrokeshire coast from Flimston.

The Flimston Erratics -- Sacred Stones!

I have just scanned this from an old slide which must be at least 50 years old..... relevant to the discussions we have had on thi blog about the presence of erratic boulders from the St David's Peninsula down on the limestone coast of South Pembrokeshire.

Because these erratics have metal plaques fixed onto them, and are therefore turned into objects of commemoration and reverence, I suppose we can refer to the stones as "sacred."  So the objects are inherently interesting.  But we should remember that there is a very strong utilitarian component here as well -- the stones in Flimston Churchyard were not "revered" because of their colour or their provenance.  They were used because they were different from the other bits and pieces of limestone lying around in the area, and because they were simply available in the locality.  They are not even "orthostats" or pillars -- they are actually rather ugly boulders.

I have always argued that exactly the same principle applied with neolithic cromlechs and Bronze Age standing stones and other features in West Wales and elsewhere.  Stones were always used because it was convenient to do so.  Reverence was not an inherent feature of the stones prior to their use -- reverence came afterwards, when the monuments created were invested by later generations with symbolism and (sometimes) with the memories of the ancestors.

So in all of this I am light years away from what Colin Richards tends to write into his articles about stones and quarries......  of which more anon.

Friday, 10 January 2014

The Parallel World of Darvill and Wainwright

 The crags of Carn Meini seen from the west -- across the "stone stream" (which is, by the way, entirely natural)

Thanks to Tony H for putting together these notes on the latest article by Profs D and W.  Please go to the original to see the illustrations.

I have added some comments at the end of the piece. 


Geoff Wainwright and Tim Darvill's article is quite informative and certainly stimulating to a non - local like myself. The healing springs notion is just one of about 4 main points discussed clearly. We are informed that Geoff's PhD was on Mesolithic Preseli, and Tim's was on Neolithic Preseli. The 8 - page article is well illustrated and includes maps e.g. of sites of oval stone circles. Comparisons are made between the distribution of various prehistoric features around the Greater Stonehenge Landscape/ area beyond and North Pembrokeshire and beyond, in the Mesolithic and Neolithic. The article would repay closer study, and maybe the authors would permit us displaying sections of it, with due acknowledgement of course.  Back - copies of C.A. cost £5.

Extract from p 20:  'From 2005 we increasingly focused on the eastern part of the Preseli Hills where the greatest concentration of sites seemed to be.  As a result, several hundred sites and findspots were logged and recorded.  Over a dozen geophysical surveys were then carried out within the [larger] survey area.   These were followed up with small-scale excavations both to examine features visible on the geophysical plots and to determine date and form at the Banc Du causewayed enclosure, Carn Menyn walled enclosure, Carn Menyn Cairn, Croesmihangel round barrow, and the Cottesmore Farm timber circle. The peat bogs on either side of the main Preseli ridge were also sampled and studied by Ralph Fyfe.   In 2008 we turned to the eastern end of the bluestone trail and excavated a small trench at Stonehenge to investigate the date and arrangement of the Double Bluestone Circle and its replacement, the Outer Bluestone Circle (Current Archaeology, issue 219).  Standing back from the results of our work over the past decade or so, three important dimensions of the ancient cultural landscapes of Preseli and Stonehenge have become very apparent.'


'The 1st finding is that big visible monuments that have traditionally attracted attention are really hotspots within a long continuous sequence of occupation spanning 6th -2nd millenium B.C. In west Wales, the coastal settlement at Nab Head, 40km from Carn Menyn, was occupied in 2 main phases during the 8th & 6th millenia BC. Environmental evidence from peat bogs at the E end of the Preselis revealed an elm decline at c. 4710-4500 BC, the oldest such event recorded within Wales and one of the oldest in Britain.  Substantial changes to the vegetation occur at this time, which most likely reflects significant later Mesolithic impact on the local landscape, including burning, heathland development, and reduction of woodland cover.

Such changes provide strong evidence for human disturbance of the vegetation around Gors Fawr Bog, to the south of Carn Menyn, during the late Mesolithic. The effects are visible in both the nature of woodland composition and the character of open-ground vegetation, most likely controlled by fire.

'The causewayed enclosure at Banc Du investigated as part of our work was constructed early in the 4th millenium BC and its ditches recut several centuries later. Settlements of the 3rd and 2nd millennia BC have been identified south of the Preselis on the coast at Stackpole Warren and inland at Woodside Camp.

There is a similar picture around Stonehenge.  Extensive occupation beside the River Avon at Downton (south of Salisbury) and Amesbury (only 3km E of Stonehenge) in the
6th, 5th, and 4th millennia is well represented. The causewayed enclosure of Robin Hood's Ball, 4km to the NW of Stonehenge, was built around 3640-3500 BC, and probably continued in use for several centuries. Houses of the mid 3rd millennium BC have been found around Durrington Walls, 3km NE of Stonehenge in the Avon Valley, and settlements of the 3rd and 2nd millennia have been investigated elsewhere in the area at Downton and Easton Down.

In its later stages, Stonehenge was surrounded by round-barrow burial monuments of many shapes and sizes. Rings of pits, known as the Y- and X- Holes, were dug around the monument's central stone settings in the mid 2nd milennium BC as if to enclose it. On Carn Menyn, barrows were built at either end of the ridge. To the west, the Carn Menyn Cairn was erected after 1420-1260 BC, covering an embanked stone circle that stood within a henge-like circular enclosure. To the east, a turf barrow was raised over a small palisaded enclosure with a foundation deposit of cremated human bone that was dated to 1930-1740 BC.'

{There is a detailed map of the great density of sites claimed around Carn Menyn reproduced in colour on page 21of the article. The so-called "Carn Menyn Cairn" is located at the NNE tip of 'Stone River' at above 310 metres height.}

There is also a coloured aerial photo of the Carn Menyn Cairn, alongside of which are illustrated Phases 1 to 4 of its excavation. Excavation, they say, revealed that this was constructed after 1420-1260 BC and covered a stone circle set within a henge-like enclosure.


'The 2nd factor is that stone was hugely important to these [Pembrokeshire and Stonehenge area] communities, a kind of raw material singled out for special attention in both areas. What exactly different kinds of stone meant to prehistoric people is unclear, but we can be certain that perceptions were different to those common today. The Roman writer Pliny the Elder (AD 23-790) for example talks of stone in terms of its magic power, supposed healing properties, and even gender, all of which provide interesting new ways of thinking about the meaning of stone.
At a very personal level, stone was used selectively. At Nab Head, slate and shale was exploited during the Mesolithic period for the production of beads, while dolerite and sandstone was used to make axes and perforated stone rings during the 5th millenium BC in a way that echoes traditions in NW France at the time.
Inland, Carn Menyn is a distinctive jagged outcrop of dolerite composed of columnar slabs rising to a height of 365m above sea-level on the southern fringe of the Preseli Ridge.  Its summit offers commanding vistas: north to the Lleyn Peninsula and S to the Bristol Channel and the Devon coast. Although the ridge is best known as one of the main sources of dolerite for Stonehenge, that was not the first kind of stone exploited here.

Our excavations at Carn Menyn show that light-coloured meta-mudstone was being quarried in the 6th & 5th millenia BC, exploiting a narrow band of workable material. Exactly when when dolerite began to be extracted at Carn Menyn is not known, but a working floor investigated in 2012 that it was certainly taking place in the last few centuries of the 3rc millenium BC, exactly the time that dolerite bluestones were being set up in the central area of Stonehenge. Our excavations also showed that meta-mudstone was again exploited in the later 2nd millenium BC, and pieces have been found sealed under round barrows and cairns of the period nearby.

In the Stonehenge landscape, there is evidence for flint-mining at Durrington 3.5 km NE of Stonehenge, and abundant evidence for flint-knapping sites throughout the area. Bluestone of all kinds was broken up and worked for the production of axes, discs, and amulets at Stonehenge itself. Pieces also leaked out into the local area, where some were deposited with burials and in the Wilsford shaft.  At least a couple of pieces found hteir way north to Silbury Hill, overlooking the Swallowhead springs and the source of theRiver Kennet (C.A 215).

'Blocks of stone in the landscape were given special treatment. In the Preselis there are propped rocks, dolmens, and portal dolmens that all involve lifting great slabs of rock out of the ground and supporting them in a way that emphasises their shape and form.  Natural boulders were sometimes given special attention by having cup-marks carved into them and platfroms of smaller stones built around them.  In the Stonehenge landscape, natural boulders again seem to have been accorded special attention. The Cuckoo Stone, lying W of Woodhenge, is a good example of this.  Investigatios by the Stonehenge Riverside Project in 2007 showed this naturally occurring sarsen had been raised upright over the hollow in which it originally lay.

'Circular and oval monuments built out of stone are a feature of both landscapes in the 3rd millenium BC. In thePreselis such monuments are widely scattered. Single and multiple concentric stone circles occur mainly on the south side of the Preseli Hills at Gors Fawr, Dyffryn Syfynwy, Eithbed North, and at the ceremonial complex centred on Glandy Cross.A curious stone oval is known high in the hills at Bedd Arthur, one of few direct parallels for the oval in the central setting at Stonehenge.


More than a dozen stone pairs have been recorded in the Preseli Hills, one of the highest concentrations in Britain. In every case they sit like portals or doorways in the landscape at the boundary betwwen contrasting environments, perhaps to mark routeways. Excavations in 1979 revealed that the Heel Stone at Stonehenge was originally one of a pair os standing stones. As with such settings in the Preselis, the Heel Stone stands right on the edge of the plateau on which Stonehenge is built. To the NW the ground dips down to Stonehenge Bottom.

Whereas in Preseli the circles and ovals are dispersed, at Stonehenge they are gathered together on the same spot, combining circles, concentric circles, and an oval. One of the things that makes Stonehenge unique is the fact that circular structures, which elsewhere were made of wood, were here made of stone. This is especially the case with the Sarsen Circle and Sarsen Trilithons, where the uprights and lintels were squared - up and dressed like over-sized planks secured together with mortise and tenon joints. Some of the bluestones may also have been treated in this way in an earlier configuration at Stonehenge or elsewhere.


'The 3rd key theme that has emerged from our work is the link between the monuments and water. In the Preseli Hills, many of the stone monuments lie close to natural springs and watercourses. At Carn Menyn, springs issue from the rocks that were the focus of quarrying and extraction. Some of these springheads have even been elaborated with the construction of a wall to create a small pool. Cairns sometimes stand around the springhead, and some springs were enhanced by the addition of rock art on stones around the rim. Water from many of the springs is considered to have healing powers, and some were adopted as holy wells in recent times.

Springs are increasingly being recognised as important focal points in the Stonehenge landscape. Investigations by David Jacques [Open University] at Blick Mead on the west side of Amesbury have revealed that the spring here is associated with activity from the 6th millenium BC through into recent times (CA 271). As well as thousands of pieces of worked Mesolithic flint, his excavations revealed a broken Bronze Age dagger, a lead object likely to be a Romano- British curse, and a 5th century AD Anglo-Saxon disc brooch. Most importantly, at Stonehenge itself, the reconfiguration of the bluestone setting in Stage 3 coincides with the construction of The Avenue as a ceremonial way leading to whatever watercourse lay in Stonehenge Bottom at this time, and then onwards 2.1 km SE to the River Avon.


'So where does that leave the bluestones and Stonehenge? At the western end of the bluestone trail [!] we have a mountain from whose flanks around 80 stones were extracted and carried to Stonehenge in the late 3rd millenium BC [!!]. These sources, spread over a fairly wide area, were closely associated with springs and watercourses, many of which were believed to have healing properties in Medieval and later times.

Over on Salisbury Plain we propose that, after the eartwork enclosure at Stonehenge ceased to be a major cremation cemetary sometime about 2500BC, bluestones from Preseli were brought and set up within a temple whose structure had already been constructed from sarsen stones.  It would be naive to think of Stonehenge having a single unchanging purpose, bu one of its roles we argue is that of a shrine to which people were drawn because of the supposed healing powers of the bluestones.

In a prehistoric context, the idea of healing should be taken to mean pastoral and medical care of both body and soul:  tending the wounded, treating the sick, calming troubled minds, promoting fertility, assisting and celebrating births, and protecting people against malevolent forces in an uncertain world. No doubt the great deities, perhaps the gods of the sun and moon, presided over the ceremonies, immortalised in the Trilithons. But the stones were not just memorials to the gods, they were active agents in promoting the well-being and fecundity of the people.  We believe that, in its heyday, Stonehenge was a place for the living.' 


An introduction to the Strumble-Preseli Ancient Communities and Environment Study (SPACES) was published in Antiquity 76, and between 2003-2011 there have been regular interim reports in Archaeology in Wales and updates in CA (issues 212 and 252). The re-dating of Stonehenge is published in Antiquity 86.

To quote the "contributors" section of this issue of CA,  "Timothy is Professor of Archaeology in the Dept of Archaeology & Anthropology at Bournemouth Uni;  Geoff was formerly Chief Archaeologist at English Heritage, and now lives in N Pembrokeshire.


This is s strange article -- and I suppose it is a sort of "end of term report" on what the SPACES project has been up to.  There is nothing new in it, and the whole thing seems to me to be a rather desperate attempt to find "connections" between Stonehenge and Preseli  and to flag up eastern Preseli as a sort of Neolithic Holy Land.  I find all of it entirely unconvincing and almost desperate in tone........  the "evidence" (such as it is) is so flimsy as to be incapable of careful scrutiny.  And as I have said before, the material relating to springs with supposed healing powers is fabricated.  The authors provide NO evidence to support their contention. 

The article is no doubt a response to the high-profile pronouncements of Prof MPP and his team over the past three years -- and I am intrigued that the article has been published in spite of the emerging evidence that Carn Meini (Menyn) was not considered a special place at all, and that the spotted dolerite orthostats and debris at Stonehenge came from somewhere else.

So we still have the two tribes slugging it out -- in the politest possible way...... Stonehenge as the Place for the Living versus Stonehenge as the Place for the Dead.   Well, it keeps us all entertained.

Thursday, 9 January 2014

Cerrig Marchogion

This is one of the current candidates as a source area for the dolerites (spotted and unspotted) found at Stonehenge.  It's a very beautiful area of tors and craggy outcrops, stretching across several hundred metres, right on the crest of the Preseli upland ridge.

For all lovers of fantasy:  This part of Mynydd Preseli has strong associations with King Arthur.  For example, in the story of Culhwch and Olwen related in “The Mabinogion” King Arthur and his knights fought a pitched battle with the monstrous boar Twrch Trwyth and his cohorts of smaller and equally ferocious smaller boars, in the depression of Cwm Cerwyn.  According to tradition the corpses of those who were slain were petrified  in the rocks of Cerrig Marchogion.  They are a bit spooky too, if you are stuck up there when the cloud comes down............

Wednesday, 8 January 2014

The Joy of Stratigraphy

When I was studying geology, the bit that I really enjoyed was stratigraphy, since it was all perfectly logical and chimed in well with those old fellows Hutton, Darwin etc etc.  The storms at Abermawr have freshened up the stratigraphic succession in the cliff face, and I was able to get some classic photos yesterday.........

The top photo shows -- in order of deposition: at the base, rough broken "rubble drift" interpreted as an accumulation of early and Middle Devensian frost-shattered debris in slope deposits, derived from the old cliff line which is still hidden.  There are some big angular blocks in it from cliff falls etc.  Above that is the Irish Sea till, a very fine-grained  lodgement till accumulated as the Irish Sea Glacier flowed across the area in the late Devensian -- around 20,000 years ago.  The base of the Irish Sea till is coloured red because oxidation processes have been at work -- from water percolating UPWARDS from the permeable deposits beneath.  There is another stained layer on top of the till, but that is mixed up with ice wastage products (flow-tills) and meltwater deposits.

The photo below shows the Lower Devensian slope deposit of angular bedrock rubble, incorporating (in the centre of the photo) a beautiful reddish-coloured erratic which must have been derived from old (Anglian) glacial deposits in the vicinity.  We see similar erratics incorporated in Early Devensian periglacial accumulations at Whitesands and elsewhere.

Interglacial raised beach exposed at Abermawr -- for the first time ever

Sorry this is such a fuzzy photo -- but it's a long-distance shot, hand-held, taken in a strong wind!  Actually it's quite a historic photo --it's the first time the interglacial (Ipswichian) raised beach has ever been seen at Aber-mawr, on the west side of the Pen Caer Peninsula in North Pembrokeshire.  I knew it was there, of course, but all previous studies of the Pleistocene sequence of deposits at Abermawr -- going back to the 1800's -- have failed to record it.  I worked here quite intensively in 1962-1965 and never saw it once, even after storms that caused cliff collapses and cleaned up the cliff face.

At last, after the dramatic events of the past stormy week, cliff falls have revealed the strip of rounded pebbles sitting on a bedrock bench (probably a part of the raised beach rock platform) in the eastern corner of the bay.  The deposits are sealed beneath a thick layer of broken debris and pseudo-stratified head -- dating from the early part of the Devensian glaciation when the climate was cold but not glacial.

By the way, there are other sites in Pembrokeshire where the Ipswichian raised beach is clearly visible beneath later deposits -- and this new discovery confirms a well-established Pleistocene stratigraphy for West Wales.

Tuesday, 7 January 2014

Submerged forest - Newgale

Another great photo of the submerged forest near the storm beach in Newgale, Pembs, following the Great Storm of a few days ago.  You only see exposures like this every few years, and this was a quite exceptional storm that has taken many thousands of tonnes of sand out to sea, revealing what lies beneath.  The storm beach ridge is in quite a state too -- and the road is still blocked.

At the height of the storm, this is what it looked like, with waves overtopping the ridge crest.

The obsession with man-made things

 Areal shot of Newgale, dated 4th January, showing the beach and storm beach ridge in the foreground, the road covered with pebbles, the surf shop and Duke of Edinburgh Inn, and the flooded valley behind.

I'm not really in a bad mood today -- but here's another thing that has upset my equilibrium.  As the jolly readers of this blog will know, one of my hobby-horses is that people look at natural things and keep on thinking of them as the masterly works of man.  Sometimes it's almost as if they wander around in the natural world without being aware of its extstence -- let alone being aware of the processes that operate within it.......

Seldom have I seen such crap reporting. On the BBC News yesterday, an intrepid young reporter who was at  Newgale with his film crew burbled on about the "flood defence system" adjacent to the road, using the term over and again.

 If he was simply to use his eyes and look at it, he would realise that the pebble beach in Newgale is an entirely natural storm ridge formed over thousands of years from glacial erratics and bits and pieces of bedrock from the adjacent coasts. It will occasionally be overtopped by storm waves, and it wants to move inland. It has moved inland several hundred metres in recent centuries -- the original Duke of Edinburgh inn was where the sand beach is today.   In fact, tradition has it that there have been at least three inns here, each one built further inland to replace its predecessor destroyed by the encroachment of the sea.   The road is of course in the wrong place -- it should be further inland, on an embankment, out of harm's way!

As for that youthful and ill-informed reporter, did he never do geography at GCSE level?

Sacred nonsense on the BBC

Is it just me, or are BBC programmes now being dummed down to such an extent that we are all supposed to just sit in front of the telly and switch off our brains?  It was my misfortune last night to watch episode 2 of the latest BBC history offering -- Neil Oliver and the sacred wonders of Bronze Age and Iron Age Britain. 

How to fill an hour with unadulterated whimsy and fantasy -- and not a fact in sight.  Are all of the senior archaeologists in the UK similarly infected by this tendency to fantasise to an extraordinary degree, on the basis of virtually no evidence?  Francis Pryor, Barry Cunliffe etc etc -- they are all at it.......  oh dear oh dear.

Thank goodness I missed the first programme -- on the Neolithic.  I would probably have succumbed to a fit of apoplexy.

Monday, 6 January 2014

Ring of Brodgar and its "quarry"

I have mentioned the Ring of Brodgar (on Orkney) in earlier posts, and having seen some mentions of it in assorted publications I have been digging a bit deeper.......

The key authority seems to be Colin Richards, whose writings all seem to be based upon the assumption that the stones were highly valued for their variable qualities (there are supposed to be seven different rock types represented in the ring) and that they were quarried from some way off -- and especially from a place called Vestra Fiold near the west coast of mainland.  A lot has been written about the excavation there, with the discovery of an "abandoned orthostat" propped up on supporting stones.....  sounds familiar?  Hmmmm.....

When people write so enthusiastically about quarries, I immediately ask myself (and them) whether they have examined very carefully the hypothesis that the "quarried" stones might have been transported and emplaced by natural agencies.  In this case, I can find no proper consideration of the thesis that the stones in the Ring of Brodgar are either (a) glacial erratics  or (b) slabs excavated locally, in the rectangular pits that are thought to have been the precursors of the ditch as it appears today, or (3) a combination of (a) and (b). The assumption in the archaeological establishment is that the stones have been transported by the builders of the Ring for maybe 10 miles from the NW towards the SE -- directly against the direction of the established last direction of ice movement across the islands.

Colin Richards (Brit Arch 2005) says this: 

We started in Orkney in 2002. Allan Hall of Glasgow University had discovered that many of the stones of the two spectacular circles, the Stones of Stenness and Ring of Brodgar, were derived from different sandstone strata. It seemed they had been brought from different sources, and places, across Orkney.
There is a neglected entry in the Royal Commission Inventory for the Northern Isles, published in 1946, in which a quarry for these two circles was tentatively identified at Vestra Fiold in western Mainland. Interestingly, it lies on a hillside just north of the contemporary late neolithic (3000-2500BC) village at Skara Brae.
Funded by Historic Scotland, the Orkney Islands council and the University of Manchester, we excavated at Vestra Fiold. We found clear evidence for methods of quarrying and moving the monoliths. The first excavation centred on two large stones similar in shape and size to those in the circles, lying in a hollow on the hillside. It seemed they had been quarried upslope and dragged down to the level ground within the hollow. The eastern monolith had then been pulled over a rock-cut pit onto two masonry trestle supports, one at each end of the stone. Unfortunately, during the manoeuvre the trestles had collapsed and the stone slipped sideways.
Most of the many students of stone transport agree that stones were likely supported on a sled running on wooden rollers. The Vestra monoliths could have been pushed downslope with relative ease directly onto rollers. Mounting the stone onto a wooden sled without damage would have been more difficult. JE Garfitt, a forestry adviser writing in Antiquity in 1979 (p190), suggested this would have been done with "levers probably aided by partial cutting away of the earth below". Perhaps this is what people had been attempting at Vestra, before calamity struck. Though undamaged, the stone had been abandoned where it fell.
A second excavation was undertaken in 2003, higher up. We uncovered a quarry, but here too disaster had struck. A massive monolith had been partially removed from the bedrock, but had broken into pieces during attempts to drag it onto stone supports. Though the area investigated was relatively small, we found evidence for the entire quarrying process and an answer as to why Vestra Fiold was chosen for monoliths.
Narrow sandstone beds with fault lines periodically produce monoliths 5-6m long, with characteristic angled tops. Not only were these beds of sufficient quality, but, with enough labour to wedge and lever stones from their bedding planes, quarrying would have been relatively straightforward.
So perhaps Vestra was simply a place that through an unusual geological formation produced "ready made" monoliths? What we do know is that the Fiold took on "sacred" qualities because an unusual long cairn was built next to the quarry.

 Wonderful stuff!  Allan Hall has kindly sent me his geological notes in which he describes the characteristics of the standing stones and stumps.  Nowhere does he discuss in depth the idea that they might be erratics, even though all of the stones seem to belong to the Stromness Flagstones, which outcrop at the monument site and in the terrain to the SE of the Ring of Brodgar.  Allan is an archaeologist, not a geologist -- but his field notes are excellent.  And in fairness to him, he was not asked by Colin to speculate about transport mechanisms.

Maps showing the outcrops of the Stromness Sandstones -- very variable, with many different sedimentation cycles -- and on the lower map, the directions of ice movement -- basically from SE towards NW.  The larger dot shows the location of Vestra Fiold, and the smaller dot shows the location of the Ring of Brodgar.  I have seen nothing in the geological work which might indicate that the orthostats in the Ring have come from the north of the island rather than from the south -- and there is one other small piece of evidence in that one stone found at the Ring appears to belong to the Eday Group, which outcrops in the south but not in the north.  That might be an indicator of glacial transport from the south coast of the island towards the peninsula on which the Ring is positioned.

In short, I see no reason whatsoever to believe any of this speculation about the Vestra Fiold "quarry" until somebody has done a careful analysis of the GEOLOGICAL evidence and can convince me that the orthostats in the ring can NOT be glacial erratics or locally derived slabs.

Here are a few items:

Also Colin Richards here:

Previous post on Vestra Fiold

Peach and Horne

Stromness Flagstone Group / Caithness Flagstone Group (ORS)

The local geology: Middle Devonian

Most of the Old Red Sandstone of Orkney is of Middle Devonian age. The lower part of the sequence, mostly Eifelian in age, is dominated by lacustrine beds of the lower and upper Stromness Flagstones that were deposited in Lake Orcadie. The two flagstones sequences are divided by the Sandwick fish bed, equivalent to the Achanarras formation of Caithness, representing an unusually persistent, deep and widespread lake that filled much of the Orcadian Basin. The sequence continues with the Rousay flagstones deposited in a similar lacustrine environment. The flagstones show a marked cyclicity in their sedimentation, with 86 such cycles being counted for the whole sequence. These are interpreted as representing regular climatically driven changes in lake level caused by Milankovitch cyclicity

The Eday Group overlies the Rousay Flagstones and represents a change to dominantly fluvial/aeolian deposition with only occasional lacustrine intervals. The Eday Group consists of three sandstone units, the lower, middle and upper Eday Sandstones separated by the Eday Flagstones and Eday Marl respectively. The Eday Marl consists mainly of red and green mudstones and siltstones and is thought to have been deposited in a river floodplain environment. Locally pseudomorphs of halite have been found and rarely marine microfossils (scolecodonts) indicating that the basin was affected by occasional marine incursions at this time.

Submerged forest reappears at Newgale

This photo was taken this morning by somebody at Newgale on St Bride's Bay, Pembs.  It shows the fresh exposure of the submerged forest following the huge storms of recent weeks.   You can see the exposures of the peat bed very clearly.

The "fluting" is interesting.  I suspect that this is an erosional phenomenon, caused by water streaming back down the beach in gullies or rills after storm waves have broken higher up the beach.  That's just speculation -- one needs to examine the place properly -- easier said than done at the moment, since the road at Newgale is still closed to all traffic.

Sunday, 5 January 2014

Geology of the Trefael Stones

 The main Trefael Stone --  photo by Paul M.  Note the cupmarks and the bluish colour on the 
broken face

The second stone near Trefael  -- once a standing stone and later dumped into the hedge?  
Or maybe once a gatepost, and later rejected?
(Photo: George Nash)

 There is an interesting letter from Rob Ixer about the recumbent Trefael Stone (and other things) in the latest edition of Current Archaeology.   I assume that the letter relates to the second stone found near the edge of the field.  I agree that this doesn't look like spotted dolerite, and that it might be an unspotted dolerite.  I'll take issue with Rob's use of this phrase:  "probably a joint block taken from a Preseli dolerite outcrop....."  Dodgy assumption.  "Derived from" would have been a better phrase for a geologist!

The presence of elongated lumps of dolerite in the tract of country to the north of the Nevern Valley is rather intriguing.  There are quite a few of them, and this led OT Jones to speculate that maybe there was at one time a glacier flowing northwards from Preseli -- he assumed that they were erratics.  There are two further possibilities:

1.  The dolerite orthostats are not from Preseli at all, but are glacial erratics carried from Pen Caer.  That would indicate ice movement west to east -- possible but not probable.

2.  The orthostats (including the one in the photo) were collected as gateposts within historical time by farmers who lived in the area.  Hundreds of gateposts throughout North Pembs are made of elongated "pillars" of dolerite -- and we know from historical records that farmers used to go up into the mountains to collect them.  Much more long-lasting than gateposts made of oak.......

More to be revealed, I'm sure.



In your recent article about the Trafael stone (CA 276), it was suggested that the (now recumbent) standing stone found close to the monument was 'probably Preseli spotted dolerite like those found at Stonehenge'. However, while careful re-examination of the photograph confirms that the rock is probably a joint block taken from a Preseli dolerite outcrop, unlike the majority of the Stonehenge dolerite orthostats, it is unspotted. Further macroscopical and new microscopical examination is required before any serious Stonehenge connection could be verified, as - despite the recent confirmation of four small spotted dolerite fragments from Silbury Hill - the dearth of authenticated spotted dolerite orthostats, or even 'debitage', within secure archaeological contexts away from Stonehenge is remarkable.
       This also appears to be true for its use in pottery, as no Stonehenge dolerite (or any other bluestone) has been recognised as temper from any [Neolithic] Grooved Ware pottery. This includes pottery found at Trafael and, more significantly, at Durrington Walls and elsewhere in Wessex. What a contrast with the Inka, who used 'off-cuts' from their highest-status buildings to use as temper in Capitol Inka/ Inka Fine Ware, their finest pottery.

Dr Rob Ixer.

Current Archeology (no. 286, January 2014)

After the storms....

The recent storms have carried out vast quantities of sand from many of the beaches of Pembrokeshire -- dumped temporarily in deeper water, and no doubt due to be carried back in again during the coming summer.  These two pictures were taken yesterday on Traeth Mawr (Big Beach) in Newport Bay. Pembs.

One benefit is that with the beach lowered by up to a metre in some places, one gets to see what's underneath.  The top photo shows an exposure of cemented Devensian till full of erratic pebbles -- this till underlies much of the beach, I suspect, and it also shows up in the estuary.  I have posted previously on the rather strange erratic boulders to be seen between the tide marks.

The bottom photo shows an extent of wave-cut platform that I have never seen before -- probably covering an area of c 1000 sq m.  It's beautifully planed off, with only minor undulations on the surface.  The bedrock here, by the way, is Upper Ordovician or Lower Silurian shales -- still seems to be some doubt about the dating.

Thursday, 2 January 2014

Seriously big ice floes

I like to keep the world informed of what is going on on the ice floe front -- so here is a fantastic satellite image dated 12th July 2007 (sorry for the delay......).  This is the Scoresby Sund area of East Greenland, and there are rather freakish conditions. 

By 12th July you would normally expect the sea ice to have broken up and to have been flushed out of the fjord system completely -- but notice the extraordinary blockage of huge floes in the main part of Scoresby Sund on this occasion.  The biggest floe (the oval one which almost stretches shore to shore) is about 20 miles across, and there are several other huge ones (up to 15 miles long) as well. The ice must have been very thick in the winter of 2006-2007 -- and this thickness has prevented the floes from breaking up into small and widely dispersed slabs.  Note that this is not glacier ice, but sea ice......  although there will certainly be some real icebergs caught up in these vast "ice islands."

Wednesday, 1 January 2014

The Garn Turne Dolmen / Cromlech

On looking at the Current Archaeology web site, I came across a reference to another article (in issue 286) by persons unnamed.  Here is the info:

Exploring Neolithic construction at Garn Turne
Dolmens are an iconic form of chambered tomb. But with capstones weighing over 100 tonnes, how were these monuments created 6,000 years ago?

If any reader of that august journal wants to share the findings of the authors, feel free to let me have the info.

Glacial Lake Brynberian

A wonderful photo with which to celebrate the arrival of 2014 --  this is actually Jokulsarlon in Iceland, a glacial lake filled with floating ice debris, mostly derived from the nearby glacier snout. (It's full of dark-coloured morainic debris, and looks very different from lake or sea ice, which tends to be clean.)  Anyway, it gives us a good impression of what Glacial Lake Brynberian might have looked like c 20,000 years ago.  You can see a further consideration of this lake and its effects here:

Just to put things in focus, here is my impression of what the lake might have looked like from the air, and a presnt-day image of the likely site of the lake:

On the upper of these photo (a flipped photo of a glacier-dammed lake on Axel Heiberg Island) you can imagine the hills as being Mynydd Preseli.  For purposes of orientation, you can imagine Craig Rhosyfelin as being deeply inundated some way off the left edge of the lower photo.

Happy New Year!!

Darvill and Wainwright come out fighting?

A little bird tells me that Profs Darvill and Wainwright have written another article concentrating on the perceived "remarkable properties" of the bluestones from Carn Meini and other sites -- and reporting on some of the more recent findings of the SPACES project.  Apparently there is a lot of emphasis on the "healing springs" idea -- yet again -- even though Robin Heath and I (and others who know the area) insist that there are NO springs with healing/sacred traditions in the eastern Preseli area at all.  I hope that we are not dealing -- yet again -- with fabricated evidence here.........

Here is the reference:
Current Archaeology (February 2014, issue 287, pp18 - 25), "Stonehenge and Preseli; exploring the meaning of the bluestones".

This isn't one of the journals I subscribe to, and it's not accessible via the web, so if anybody wants to post a note about the article, feel free to send it in!