Pages

Wednesday, 24 January 2018

Perched block near Lake Superior


This is rather splendid a perched erratic block left at the end of the Wisconsin glaciation not far from the shore of Lake Superior.  it was published on Pinterest -- not sure who the photographer was.....

Monday, 22 January 2018

Field et al 2015: the Stones


EH Plan of the stones, using the Petrie numbering system

Following on from our previous post:
https://brian-mountainman.blogspot.co.uk/2018/01/field-et-al-2014-landscape-and.html

we now come to

Reference:

David Field, Hugo Anderson-Whymark, Neil Linford, Martyn Barber, Mark Bowden, Paul Linford, Peter Topping, , Marcus Abbott, Paul Bryan, Deborah Cunliffe, Caroline Hardie, Louise Martin, Andy Payne, Trevor Pearson, Fiona Small, Nicky Smith, Sharon Soutar and Helen Winton (2015). Analytical Surveys of Stonehenge and its Environs, 2009–2013:
Part 2 – the Stones. 
Proceedings of the Prehistoric Society, 81, pp 125-148 

Abstract

Non-invasive survey in the Stonehenge ‘Triangle’, Amesbury, Wiltshire, has highlighted a number of features that have a significant bearing on the interpretation of the site. Geophysical anomalies may signal the position of buried stones adding to the possibility of former stone arrangements, while laser scanning has provided detail on the manner in which the stones have been dressed; some subsequently carved with axe and dagger symbols. The probability that a lintelled bluestone trilithon formed an entrance in the north-east is signposted. This work has added detail that allows discussion on the question of whether the sarsen circle was a completed structure, although it is by no means conclusive in this respect. Instead, it is suggested that it was built as a façade, with other parts of the circuit added and with an entrance in the south.

Quote:  

"Eighty-six stones are visible at Stonehenge, including four stumps (Fig. 2); the 20th century excavations revealed a further ten buried stumps making 96 in all. These stones are coarsely divided between the sarsens, a hard sedimentary silcrete, and the ‘bluestones’, a catch-all term covering a variety of rock types of distant origin including spotted/unspotted dolerite, rhyolites/rhyolitic tuffs (Ixer & Bevins 2011; Bevins et al. 2012), volcanic ashes, a Devonian sandstone (the Altar Stone), and other sandstones (Thorpe et al. 1991)."

Concerning the sarsens and the recent attempts to designate "origins" on the Marlborough Downs and other distant localities: Quote:  "Flinders Petrie in particular, who carefully surveyed the stones and whose numbering system is used here, considered that the very position of Stonehenge may have been determined by the presence of a quantity of sarsen (Petrie 1880), while William Gowland (1902, 75, 115), who excavated at Stonehenge at the outset of the 20th century, similarly thought the stones were brought from ‘no great distance from the spot where the structure stands’. The geologist Prof. J. W. Judd (1902, 115–6) considered that they had been moved ‘only a few hundred yards’, while H. H. Thomas (1923, 242) also thought that they may have come from ‘the site of Stonehenge itself’. Johnson (2008, 121) has suggested that the Heelstone is too awkward and bulky a shape to move on rollers and it, at least, is unlikely to have travelled far. Equally the much smaller Station Stones could easily have a local origin: it is, after all, possible to find larger stones on Salisbury Plain without having to travel to the Marlborough Downs for them." 

The authors suggest that (on the basis of field examination coupled with analysis of the laser scan data) there are at least three different types of sarsen present, potentially indicating that the stones originate from several sources. On different colours: "the majority of the stones are grey, but Stones 54, 55, 101, and 156 exhibit an orange hue while Stones 53, 56, and 154 are purple-grey. "  So the interpretation seems to be that the sarsen stones have been collected up from all over the place, and have not come from a "targetted" quarrying or collecting area in the Vale of Pewsey or somewhere else far to the north.

This is interesting too, regarding stone weights:

"Stone 56 has been cited as weighing 30–50 tons yet, assuming a specific gravity of 2.4, this study calculates the above ground weight to be 23.06 tons, while the known below-ground ele- ment (2.52 m: 22% of the stone) would increase this to c. 28.1 tons, ie, substantially less than the previous estimate. The visible parts of sarsens in the outer circuit vary between 11.1 tons (Stone 21) and 23.5 tons (Stone 16), with most stones bracketed between 13 and 17 tons. Assuming that some 25% of these lie below ground, it can be estimated that the stones in the Sarsen Circle weigh between c. 14.75 and 31.5 tons, with an average of c. 20 tons."

"Assuming that dolerite has a specific gravity of 3, the above-ground weight of the pillars in the Bluestone Horseshoe ranges between 0.96 (Stone 61) and 2.16 tons (Stone 69). As excavation of stones 68, 69 and 70 revealed that between 33% and 40% lay below ground; their estimated weight might be 3.35 tons, 3.24 tons and 2.05 tons, respectively. Stones in the Bluestone Circle are typically not as tall as those in the Bluestone Horseshoe and, due to the numbers that are broken or fallen, it is not possibly to calculate their average weight. In any case they decrease in size towards the north-east. Stone 33, however, has an above-ground weight of 0.51 tons and excavation revealed that c. 1.03 m of it was below ground, allowing its total weight to be estimated at 0.82 tons. In contrast, the above-ground portions of Stones 49 and 31 weigh 1.11 tons and 2.04 tons respectively, and excavated profiles indicate that 39% and 45% of the respective stones was below ground, allowing their total weights to be estimated at 1.82 tons and 3.72 tons."

The great majority of stones (both bluestones and sarsens) have traces of working on them -- mostly associated with pounding with hammerstones of various sizes.    There is a long discussion of the evidence for tooling or working, but there isn't much discussion at all on which surface features may be natural and which are tooled, and on WHY a lot of time has apparently gone into bashing large stones with smaller stones.  Was the idea simply to turn irregular stones into rectangular ones which would be easier to build with?  But of course the evidence of mortice and tenon joints  and tongue and groove joints is compelling, and these are clear evidence that the builders were seeking to use woodworking techniques in a world of stone.  The feeling seems to be that the sarsens have for the most part been shaped for use at Stonehenge -- maybe involving different settings at different times, but that the bluestones may have been used and shaped elsewhere before being brought in to their present positions:  "All of the extant stones in the Bluestone Horseshoe and three in the Bluestone Circle (Stones 150, 36, and 45) have been finely dressed. However, scars resulting from the removal of tenons from the tops of Stones 67, 69, 70, and 72, and the repositioning of Lintels 150 and 36 as uprights, indicate that these stones have been reused from an earlier bluestone structure, probably once located in the Q and R Holes, though possibly elsewhere."  Where was this "elsewhere"?  As we know, MPP and various other authors are very attracted by the idea of a "proto-Stonehenge" made of bluestones  somewhere in the Preseli district which was dismantled and carted off, lock, stock and barrel to be incorporated into Stonehenge..........  And as incorrigibly as ever, after years of trying, they are still hunting for the mysterious site.

One thing which is disappointing about this paper is that the authors do not consider the extent of surface weathering on the bluestones, and what that might mean for their origins and dates of emplacement.  Neither do they consider stone SHAPES -- instead simply carrying on the promotion of the idea that the preferred shape for the "ideal bluestone monolith" was a pillar or column.  In doing that, they ignore the fact that most of the bluestones are not pillars at all, but boulders and slabs.  This is hugely important, suggesting that the stones are more likely to be a glacial erratic assemblage rather than a set of carefully selected monoliths.

Coming next, in another post:  interpreting the stone settings. (p 134)

Submerged forest Abereiddi



Here is a great photo of a fallen tree in the submerged forest -- exposed in 2014 at Abereiddi on the N. Pembs coast.  Taken by Dan Soper and posted on Facebook.....

Some nice glacial geomorphology




Many thanks to Dave for bringing this to my attention.  It shows the value of LIDAR imagery, and a huge amount of detail showing the relations between various types of glacial erosional and depositional landscapes.  Puget Sound area?  Now that looks like the sort of place I'd really like to visit.......

http://www.dnr.wa.gov/publications/ger_presentations_coe_glacial_landforms_puget_lowland.pdf




Close-up of part of the map, showing drumlins and fluted moraine --classic streamlining features.   Not much doubt about the direction of ice flow here.........





Friday, 19 January 2018

Field et al 2014: The Landscape and Earthworks



Reference:
David Field, Neil Linford, Martyn Barber, Hugo Anderson-Whymark, Mark Bowden, Peter Topping, Paul Linford, Marcus Abbott, Paul Bryan, Deborah Cunliffe, Caroline Hardie, Louise Martin, Andy Payne, Trevor Pearson, Fiona Small, Nicky Smith, Sharon Soutar and Helen Winton (2014). Analytical Surveys of Stonehenge and its Immediate Environs, 2009–2013:
Part 1 – the Landscape and Earthworks.
Proceedings of the Prehistoric Society, 80, pp 1-32 
doi:10.1017/ppr.2014.6

Quote:

The Project brought to bear an integrated array of non-invasive survey techniques, including earthwork analysis, geophysics, laser scanning, and aerial survey, together with documentary and archive research. All monuments in the World Heritage Site with a visible surface component were investigated........

This part of the paper concentrates on everything other than the stones, within and beyond the Stonehenge earthworks.  There are many interesting observations.

Figure 2 from the paper, showing the twentieth century excavated area.  It is still the case that only about 50% of the area occupied by the stone monument has been excavated.    So the stratigraphy is still only partly known, as is the nature of the Stonehenge Layer and the characteristics an origins of the stones and fragments that happen to have been collected.  If anybody says to you "Twenty percent (or whatever) of the rhyolite debitage at Stonehenge has come from the Rhosyfelin area", what they actually mean is "twenty percent of the rhyolite samples that happen to have been collected from the bits that we know something about......."

There is a short section on the "periglacial stripes" described so lovingly by MPP and his colleagues, but it's disappointing that the authors do not really examine the very dodgy use of this "periglacial" label -- and in the process perpetrate the myth.  As I have said many times before, I  see no reason to use the periglacial label myself, in spite of being rather fond of periglacial geomorphology, since the most parsimonious explanation of these "parallel stripes" is simply that they are solutional rills formed by water flowing downslope on a shallow gradient over many millennia. Field et al say "it seems most likely that they (the stripes or rills) represent a geological interface, perhaps concentrated flint or marl seams embedded within the underlying chalk."  I agree with that 100%.

As for the MPP idea that Stonehenge is where it is, and the alignment of the Avenue is what it is,  because of the alignment of these rills -- the authors are mercifully silent, suggesting to me that they don't think much of it........

 More attention is given to a little mound -- just 25 cm high, in the southern part of the stone setting.  It's about 15 m across, and has an irregular surface.   Apart from assuming that it is natural, the authors are a bit mystified by it.  Something to do with the irregular surface of the chalk?  Something to do with the Stonehenge Layer?  Something to do with solution hollows or the past location of sarsens removed and erected on the site? 

 Quote: "Several authorities have suggested that the sarsens were sourced from the area of Stonehenge or somewhere closely adjacent (see below). Darvill et al. (2012, 1029) have recently suggested that some stone was probably present on site at the outset; notably the massive cone-shaped Heelstone as it has been considered to have been extremely difficult to move (Johnson 2008, 121), an observation supported by measurements taken from the laser scan data which demonstrates that it is the heaviest stone on site (Abbott & Anderson Whymark 2012; Field et al. forthcoming). "

There is some interesting wotk on the barrowes (we won't delve into tht just now), with a suggestion that some of them may have originated as long barrows and that there may have been a number of phases of construction / modification.  Quote: "It is clear that far from being isolated, Stonehenge may have been a component part in a ceremonial and funerary area within its immediate environs, with origins and traditions potentially traceable to the earlier Neolithic.  Initially at least the focus of activities may have been around one or more of these other monuments." Interesting.......

Now to the North and South Barrows within the Stonehenge earthworks.  Yet more interesting info. The authors suggest that the North Barrow is not younger than the  rest of the monument (as normally assumed), but is probably older.  The interesting thing about this is that Atkinson recorded bluestone chips in its bank -- and if his records are correct, that must mean that bluestone fragments were present on this site BEFORE the Stonehenge embankment was constructed.  This is a highly significant finding, and I am not aware of any comments on it thus far in the recent literature.  This paper accepts that the bank and ditch were built around 5,000 yrs BP.




There is a detailed and fascinating discussion of the embankment, ditch and Avenue, and the relations between them -- very fastidious and well described, and mercifully free of speculation.  Then the authors go on to describe the barrows in the Stonehenge landscape, and the Y and Z holes.

Overall, the most interesting things to come out of this paper are:

1. The so-called periglacial stripes are not accorded any great significance, either in landscape terms or in the interpretation of the Avenue or the Stonehenge area as a whole.

2.  The authors appear to have no problem with the idea that many or most of the sarsens at Stonehenge have come from the neighbourhood.

3.  If the North Barrow is indeed older than the Stonehenge embankment, it shows that bluestone fragments were present in this landscape before work started on the Stonehenge earthworks.    That of course would support the thesis that other long barrows could contain bluestones as well -- and that the Boles Barrow bluestone was indeed embedded in the Neolithic long barrow there,  well before Stonehenge was thought about.......















Investigating the Stonehenge Triangle

The triangle investigated in this study


Many thanks to Rob for drawing these to my attention.  Somehow, we all missed them before! But these are important papers, one dated 2014 and the other 2015.  Actually, they are two parts of a single long article, with multiple authors.  The authors stress that there is no new digging here -- this research is all "non-invasive", but it's nonetheless interesting and important, adding a lot to our understanding of the triangle of land referred to as the EG "guardianship area", north of the A303 road.

I'll refer to these two papers as Field et al (2014) and Field et al (2015).

Here are the details:

David Field, Neil Linford, Martyn Barber, Hugo Anderson-Whymark, Mark Bowden, Peter Topping, Paul Linford, Marcus Abbott, Paul Bryan, Deborah Cunliffe, Caroline Hardie, Louise Martin, Andy Payne, Trevor Pearson, Fiona Small, Nicky Smith, Sharon Soutar and Helen Winton (2014). Analytical Surveys of Stonehenge and its Immediate Environs, 2009–2013: 
Part 1 – the Landscape and Earthworks.
Proceedings of the Prehistoric Society, 80, pp 1-32 
doi:10.1017/ppr.2014.6

ABSTRACT

Integrated non-invasive survey in the Stonehenge ‘triangle’, Amesbury, Wiltshire, has highlighted a number of features that have a significant bearing on the interpretation of the site. Among them are periglacial and natural topographical structures, including a chalk mound that may have influenced site development. Some geophysical anomalies are similar to the post-holes in the car park of known Mesolithic date, while others beneath the barrows to the west may point to activity contemporary with Stonehenge itself. Evidence that the ‘North Barrow’ may be earlier in the accepted sequence is presented and the difference between the eastern and western parts of the enclosure ditch highlighted, while new data relating to the Y and Z Holes and to the presence of internal banks that mirror their respective circuits is also outlined.


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

David Field, Hugo Anderson-Whymark, Neil Linford, Martyn Barber, Mark Bowden, Paul Linford, Peter Topping, , Marcus Abbott, Paul Bryan, Deborah Cunliffe, Caroline Hardie, Louise Martin, Andy Payne, Trevor Pearson, Fiona Small, Nicky Smith, Sharon Soutar and Helen Winton (2015). Analytical Surveys of Stonehenge and its Environs, 2009–2013: 
Part 2 – the Stones. 
Proceedings of the Prehistoric Society, 81, pp 125-148
doi:10.1017/ppr.2015.2


ABSTRACT

Non-invasive survey in the Stonehenge ‘Triangle’, Amesbury, Wiltshire, has highlighted a number of features that have a significant bearing on the interpretation of the site. Geophysical anomalies may signal the position of buried stones adding to the possibility of former stone arrangements, while laser scanning has provided detail on the manner in which the stones have been dressed; some subsequently carved with axe and dagger symbols. The probability that a lintelled bluestone trilithon formed an entrance in the north-east is signposted. This work has added detail that allows discussion on the question of whether the sarsen circle was a completed structure, although it is by no means conclusive in this respect. Instead, it is suggested that it was built as a façade, with other parts of the circuit added and with an entrance in the south.

I'll devote separate posts to these two articles..... watch this space.

More about Durrington Walls and animal teeth


Affinities of sampled animal remains at Durrington Walls with UK environmental / geological contexts -- source:  Current Archaeology

There's an interesting article in Current Archaeology 334, published in connection with the exhibition in the Stonehenge Visitor Centre called "Feast!  Food at Stonehenge."    It's by Hilts et al, and summarises much info already published about the feasting that went in at Durrington Walls, possibly at the time when a lot of work was going on at nearby Stonehenge, around 4,500 yrs BP.

Neolithic food miles: Feeding the builders of Stonehenge
Hilts, C., Greaney, S., Madgwick, R. and Parker Pearson, M. 2017. Neolithic Food Miles: Feeding the 'builders of Stonehenge'. Current Archaeology 334: 26-31.

The article concentrates on the animal remains, and the latest findings (from Richard Madgwick of Cardiff University) bring up to date the earlier info discussed on this blog about strontium isotopes in the teeth of cattle and pigs.   They can be matched to specific geological locations -- or more accurately, to specific rock types and environments.   Sure enough, as suggested earlier, some of the animals slaughtered and eaten in these jolly BBQs  were from far away, but the great majority (percentages are meaningless in this sort of context) were from "middle England" -- 65 of the animals probably having been raised within 50 miles of Durrington Walls.  Of those that were clearly not local, 14 pigs and 4 cattle appear to have come from the south of Cornwall, at least 180 miles away. Only 14 pigs and 4 cattle appear to have come from more distant parts, "at potential locations as far-flung as west Wales, upland northern England, and perhaps even north-east Scotland."  It is of course interesting that cattle and pigs were being driven to Durrington over distances of 200 miles or more -- but there is no justification whatsoever in the evidence presented for suggesting "west Wales" as a place where some of these cattle and pigs were raised.  (The only reason for that mention is, of course, that MPP and his colleagues are desperate to establish a connection, for reasons that are obvious........)  It's much more likely that the little group of animals that appear to have connections with the pink areas on the map came from SE Wales and the Welsh borders.

So there is nothing in this article to show that there was any sort of  "special relationship" between Salisbury Plain and Pembrokeshire -- and this of course is the conclusion we have to reach when we look at many other cultural indicators as well.  Please forget all that stuff about "political unification".......




Tuesday, 16 January 2018

Drygalski Mountains, Antarctica




Couldn't resist posting these fabulous images from Michael Martin's collection.   They are from the Drygalski Range in Antarctica -- and extraordinary set of nunataks in which massive vertical cliffs  and sharp peaks abound.

You can see the location of the lower photo in the upper one -- it's the huge vertical cliff to left of centre, with a vast snowfield beyond.  Look at the men for scale..........

POSTSCRIPT
Found another wonderful image....



Wednesday, 3 January 2018

Happy New Year!


Happy New Year to all of the jolly followers of this blog -- may it be kind to all of us as we press on with our quest for the truth!

The pic is from Blidö in the Stockholm Archipelago -- I think I took it on the shortest day of the year.   Bright sun, low pressure, VERY high water, and ice around the edges of the bay.  You can see some thin surface ice in the photo.  Ice forms in places where the water is still and when air temperatures are around -4 deg C.  The water temperature is around -2 deg C at the moment.   We had a sauna the other day, and gently subsided into the water -- it was less traumatic than might be supposed......

At present there are about 6 hours of daylight each day -- its getting lighter now by 2 mins every day. On 21st December it was pitch black at 3 pm.