Could the Stanton Drew stones be glacial erratics?

See these:

https://davidrabram.substack.com/p/decoding-stanton-drew

https://usercontent.one/wp/ramblingon.mendipgeoarch.net/wp-content/uploads/2023/07/Stanton-Drew-Sone-Circles_observations-and-notes-on-rock-types.pdf?media=1712675554

Thanks to Vince Simmonds for the followingn (2023):

Stanton Drew Stone Circles: observations and notes regarding the sourcing of the various rock-types used in the construction of the monuments.

Vince Simmonds BSc PgCert PCIfA FGS

The four main rock types represented in the Stanton Drew circles are as follows:

1.  Oolitic Limestone – Jurassic 205 – 142 Ma (figure 3). These rocks are a pale grey- yellow colour, although this is difficult to fully distinguish due to a substantial lichen cover. The surface of the blocks resembles a limestone pavement and has numerous cup-like depressions and pits that partly fill with water. Many rock art sites have flat slabs of stone open to the elements and, when it rains, the cup-and-ring marks fill with water, rocks with natural cup marks are often utilised for the same effect. It could be that places where rocks ran with water or held water were culturally significant in many ways (Fowler and Cummings, 2003: 10). It is possible that some of these limestone slabs at Stanton Drew were not intended to stand or were used as capstones.

2.  Silicified Dolomitic Conglomerate - Triassic 248 – 205 Ma (figure 4). These rocks have a wide range of colours from pale pink to orangey pink with some bright, sometimes ochreous orange, through to dark rust, and purple-red blotches, the red and orange colour is indicative of the mineral iron content of these Triassic rock types. The rocks have a glassy, metallic appearance and feel and the surface can be described as pitted, pock-marked, frothy, knobbly, and gnarly. There are abundant quartz geodes that make many of the stones sparkle, William Stukeley (cited in Lloyd Morgan, 1887: 39) remarks that “it shines eminently and reflects the sunbeams with great lustre”. Quartz was a highly significant and regarded material in prehistory as indicated through its use in various monuments (Lewis: online accessed 2010). There are some silicified fossil fragments from the remains of limestone clasts within the conglomerate. The varying clasts range from sub-rounded to sub-angular, fine to coarse gravel to pebble and cobble size. The majority of the stones have a substantial cover of lichen with some moss and grass.

3.  Dolomitic Conglomerate – Triassic (figure 5). This is a weathered pale grey-pink and has a lesser degree of silicification. The varying clasts range from rounded to sub- angular fine to coarse gravel, pebbles and cobbles of limestone and sandstone. There are also some silicified fossil fragments from the remains of limestone clasts within the conglomerate and the stones again have a substantial cover of lichen.

4.  Pennant Sandstone – Carboniferous 354 – 290 Ma (figure 6). These rocks are of a pink to fawn colour and distinct bedding layers are clearly visible in particular cross-stratification which is typical of material that has been laid down in deltas. There is a layer of rounded to sub-rounded fine to medium gravel of quartz.

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Vince and others are very reluctant to get into detailed provenancing, but it appears that the majority of the Stanton Drew stones have come from the SW, in or on the edge of the Mendips, around Harptree and the Chew Valley Lake.  The Stanton Drew studies do refer to stone collection, but Kellaway seems to be the only geologist who has seriously suggested origins as glacial erratics.  In most of the articles I have looked at, Kellaway is not even mentioned, and the only theory being considered is that of human stone collection.  That's not surprising...........

So let's revisit the idea.  Could the stones -- or at least some of them -- have been transported by ice and then gathered up from an erratic scatter?  Answer -- yes. The maximum distance of erratic travel may well have been about 8 km.   I have suggested many times that the Mendips might at one stage have hosted a small independent ice cap, and that this might at one time (or more often) have been incorporated into the far eastern edge of the Irish Sea Ice Stream.  If this was the scenario, ice might well have affected the Chew Valley Lake area and Stanton Drew, flowing from  south-west towards north-east.  If glaciological conditions were right, the entrainment and transport of boulders in this area was quite possible.

Too many "might" and "may have" provisos?   Quite so -- but this does justify some further consideration......... and I need to work out how topographic controls might have been exerted.