Debunking Pigs From Scotland

 Last year I did a round-up of the Isotope evidence for "neolithic pigs from Scotland"  - https://www.sarsen.org/2022/10/strontium-values-reappraisal-south-west.html . 

I missed another paper that came out a fortnight later:

Applying lead (Pb) isotopes to explore mobility in humans and animals - Evan et al

Dr Gordon Barclay kindly pointed this out to me and so I should update the record:

The paper is open access, so please read it. The key passage is:

Key to this study is our ability to distinguish between northern and southern British Pb sources and this can be achieved because of differences in the underlying geology between these two parts of Great Britain. The Pb isotope composition of rocks and minerals tends to be dominated by major geological tectonic events such as mountain building, which is accompanied by metamorphism and the intrusion of granites, the heat from which drives the re-mobilisation of Pb to create ore deposits.

The junction between these two tectonic plates is called the Iapetus Suture and it runs on a NE–SW line from Berwick-upon-Tweed to the Solway Firth and projects into Ireland.The underlying geology to the north and south of this suture is fundamentally different; the Laurentian basement, to the north, is geologically much older (> 3000Ma–c. 1750Ma) and is depleted in uranium (U) whereas the Avalonia basement in the south is geologically much younger (c. 700Ma), and this means the Pb isotope compositions, related to the basements of the two areas, are different. As this geological boundary essentially defines the modern political border of Scotland with England, it provides a potential method of discriminating between Scotland and the rest of Great Britain.

The conclusion is quite clear, in their opinion: 

"We have tested this application using a sample of Neolithic pig enamel from sites in southern England, some of which, because of Sr isotope composition, could not be excluded from an origin in northern Britain. Pb isotope data from the teeth excludes Scotland as a source but the diverse range of Pb isotope results, combined with other isotope proxies, are consistent with the animals being raised on a variety of lithologies of diverse age and from variable environments."

So is this end of the idea of neolithic links between Scotland and Stonehenge, I wouldn't bet on it.