Resolving archaeological populations with Sr-isotope mixing models

Strontium isotope analysis of tooth enamel is a useful provenancing technique to investigate the childhood origins and residential mobility of ancient people. However, where different geographical target regions have similar biosphere 87Sr/86Sr it is often difficult to resolve the 87Sr/86Sr ranges of two different groups of people and establish what constitutes the local range at each site. Here a multi-period study is presented from the Outer Hebrides, Scotland and an investigation of Neolithic and Early Bronze Age populations from the Yorkshire Wolds, NE England. The aim is to demonstrate that, despite complex human dietary strategies, simple mixing systems with only two end-members do occur in archaeological human populations in certain geological provinces and, despite overlapping 87Sr/86Sr ranges, it is possible to separate two populations based on the structure within the data set.