A few weeks ago I watched a YouTube video of Peter MacDonald being interviewed in the Dundee Design Museum, expanding on research into the temporal and regional origin of the wool used to make the cloth. Originally I misunderstood important statements, concluding that DNA analysis had been used to identify where the "donor" sheep lived, and Professor MacDonald kindly corrected me to note that it was comparative isotopic analysis of 13-C and 15-N that led to inference of the location within Scotland where the sheep had lived, with 14-C dating used to help estimate the age of the fabric.

I've just done a preliminary search of primary literature, attempting to determine what the geographic precision of such measurements might be, but didn't uncover information that would allow such inferences. Many of the references I found came from China, but my knowledge of Chinese geography is almost nil.

I'm hoping someone who knows might chime in with suggestions about where I might read more on this topic.

Thanks so much.