One of the most widely used tools archaeologists have at their disposal to decipher where prehistoric humans lived and traveled is the element strontium. Because strontium isotope levels in remains match the concentrations in the surrounding landscape, scientists can track migrations. While the technique itself is sound, the baseline levels of strontium in different geographies may not reliably reflect ancient times as scientists have assumed.
Researchers from Aarhus University in Denmark published a report in Science Advances [March 13] showing that the data on strontium levels in soil and water used for these archaeological studies are not always accurate. With their new analysis, the team found that two Bronze Age human remains, Egtved Girl and the Skrydstrup Woman, who both died and were buried in Denmark, were not necessarily the international travelers that prior studies have suggested.
It turns out that limestone contains a lot of strontium and is used heavily in modern day farming, which increases the amount of strontium in surface waters such as lakes. This means that strontium levels from farmed regions are higher than they were in prehistoric times, creating a potential mismatch between ancient remains and modern soil samples.
Read full, original post: Modern Human Activities Muddle Analyses of Prehistoric Migrations