More on the West Kennet granidiorite mystery

Some of the coherent cobbles found at West Kennet.  They are interpreted as "corestones" or solid rock remnants which have survived while the outer parts of a boulder (or several) are weathered away.

Cunyan Crags -- a possible source area

Here is a new article on the mystery of the strange rotten granidiorite bits and pieces found at West Kennet. The article is not out yet in printed form -- it is dated as 2025.  It's a detailed paper, and although the authors (as ever) tend towards an explanation of the boulder as "yet another possible example of Late Neolithic long distance prehistoric transport" they admit to being puzzled.  Are they correct in indicating that the 77 bits have possibly all come from one boulder derived from the Cunyan Crags area of Cheviot, in Northumberland?  Time will tell.........

Of course, boulders such as this one could have been picked up by overriding ice and carried southwards -- rather like the Whin Sill erratics described by Olwen Williams-Thorpe and others many years ago. But why on earth would anybody want to collect the boulder (if it was just one) from a till exposure or from a glaciated ground surface and cart it off to West Kennet?

https://brian-mountainman.blogspot.com/2021/11/breaking-news-another-igneous-erratic.html

https://brian-mountainman.blogspot.com/2012/01/whin-sill-erratic-cluster-in-stevenage.html

https://brian-mountainman.blogspot.com/2012/04/chunk-of-whin-sill-in-london.html

"Geochemical provenancing of igneous glacial erratics from Southern Britain, and implications for prehistoric stone implement distributions" by Olwen Williams-Thorpe, Don Aldiss, Ian J. Rigby, Richard S. Thorpe, 22 FEB 1999, Geoarchaeology, Volume 14, Issue 3, pages 209–246, March 1999

http://onlinelibrary.wiley.com/doi/10.1002/%28SICI%291520-6548%28199903%2914:3%3C209::AID-GEA1%3E3.0.CO;2-7/abstract

Put this down as one of the mysterious boulders of Southern England and the Channel coasts..........

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Rob Ixer, Richard Bevins, Nick Pearce, Duncan Pirrie, Josh Pollard, Alex Finlay, Matthew Power and Ian Patience. 2025 "Exotic granodiorite lithics from Structure 5 at West Kennet, Avebury World Heritage Site, Wiltshire, UK." Wiltshire Archaeological & Natural History Magazine, vol. 118 (2025), pp. 1–18




ABSTRACT


Seventy-seven pieces of very weathered pyroxene-bearing granodiorite corestone excavated from trenches 2, 3 and 9 within Structure 5 of West Kennet in 2019 and 2021 and varying from small pebbles to >500grms cobbles, have a total weight of 22kg. Detailed petrographical and geochemical analyses of typical samples show them to share an unusual (for Britain) and distinctive mineralogy and petrography and also suggest they are all from a single outcrop/subcrop. The essentially unaltered pyroxene-bearing granodiorite carries ‘large’ skeletal zircon crystals, which are a determinative characteristic. Petrological comparisons with similar British granodiorites show that its origin is to be found within the large, 60km and lithologically highly diverse Cheviot Igneous Complex of Northumberland, more than 450km from West Kennet. Three Cheviot samples were selected for comparative analysis, one chosen for its petrographic similarity to the corestones, as suggested by previous workers, a second, close to the first and also to significant Neolithic activity at Threestoneburn Stone Circle, and finally a third based on petrography and notable topography, namely Cunyan Crags.  Only the last sample shares a sufficient number of similarities that there warrants further investigation in that area. The corestones are highly exotic with regard to their find spot and although it is difficult to conceive of any practical use for them, West Kennet provides yet another possible example of Late Neolithic long distance prehistoric transport, a distance of between 450km if taken from outcrop and 150km if collected from secondary glacial drift sources, although North Sea coastal glacial tills as a source for the stones appears unlikely and from East Anglia very unlikely. The original Cheviot Hill location remains unidentified but is being actively sought.