Strontium isotope maps are disturbed by agricultural lime
(PHYSorg.com Archaeology & Fossils)

Strontium isotopes are frequently used in archaeological studies to establish the provenance and migration history of prehistoric people and artifacts. Many of these studies may be based on incorrect data. A Danish study shows that agricultural lime can alter the composition of strontium isotopes dramatically, so that the modern isotopic signature of an area may be very different from the prehistoric signature.