I saw the last traces of the Tyning's Stones about 9 years ago (on private land). Antiquarians describe the 2 stones as having lain prostrate for at least the last few hundred years. Tucker (1884) described them thus:
Stone 1 - 5ft long by 3ft5" wide by 2ft3" thick
Stone 2 - 5ft9" long by 5ft5" wide by 1ft8" thick
Stukeley also noted an upright stone, that I have christened the Tollhouse Stone (Lewis 2002 and 2005). Stukeley linked this stone with Hautville's Quoit, naming them both "Hautvil's Coyts" (Legg 1998: 27). This was shown on his plan as north of the present B3130 road and west of the tollhouse. It no longer exists today and its exact position is unknown but it is possible to estimate that it would have been approximately 500m north-west of the great circle. It probably suffered a similar but more devastating fate to Hautville's Quoit, being broken up for road metalling.
In terms of the types of stones, there are two types of dolomitic conglomerate (Mendip/Broadfield Down), 2 types of sandstone (Mendip and ?Avon Gorge) and oolitic limestone (Dundry). It does seem likely that many of these could have been transported by river (see also Lewis 2005).
Legg, R 1998. Stanton Drew: Great Western Temple. Wincanton Press.
Lewis, J 2002. Stanton Drew Circles & Stones Past and Present. Folder Guide No.4, Bristol and Avon Archaeological Society.
Lewis, J 2005. Monuments, Ritual and Regionality: the Neolithic of Northern Somerset. B.A.R. Archaeopress.
Tucker, J. Allon 1884. 'Stanton Drew' in Proceedings of the Bath Natural History and Antiquarian Field Club 5, pp.257-264.
Found in Pevsner - North Somerset 1958. interesting fact,
He mentions that there was... l mile to the NW of Hautville Quoit, two similar stones in a field called Middle Ham.
Checking back to Burl in "Carnac to Callanish" possible grid.ref. at ST591 633, under Lower Tyning - 2 adjacent prostrate stones (now presumably lost).
Pevsner also goes on to describe the Stanton Drew stones as
"dolomitic conglomerates of different kinds, probably from near Harptree; sandstones of uncertain origin; and a jurassic limestone - probably Dundry stone.
The Harptree connection is interesting because Burl mentions two stones (now lost) at Shrowl Field, East Harptree called The Devils Quoits (what else).
How did these stones travel, by the river Chew maybe...