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 >500 grms cobbles, have a total weight of 22 kg. 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, 60 km2 and lithologically highly diverse Cheviot Igneous Complex of Northumberland, more than 450 km 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 Threestone burn 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 450 km if taken from outcrop and 150 km 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.
(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, 60 km2 and lithologically highly diverse Cheviot Igneous Complex of Northumberland, more than 450 km 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 Threestone burn 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 450 km if taken from outcrop and 150 km 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.
| Original language | English |
|---|---|
| Journal | Wiltshire Archaeological and Natural History Magazine |
| Publication status | Accepted/In press - 2 Oct 2024 |