The origins of the human remains from Perrins Ledge crematorium: strontium isotope ratio assessment of archaeological cremains

Abstract

Strontium isotope (87Sr/86Sr) analyses have been used effectively to reconstruct the origin of osteological remains that have not been exposed to increasing temperatures (Bentley, 2006; Juarez, 2008; Knudson et al., 2005). However, previous research has shown that no thermally induced changes occur to original strontium isotope values (87Sr/86Sr) of bone and teeth specimens that have been subjected to temperatures between 212 and 1832 degrees Fahrenheit (Beard and Johnson, 2000; Grupe and Hummel, 1991; Harbeck et al., 2011), though the published literature regarding strontium isotope ratio stability and survivorship in thermally altered bone and teeth is limited. This is surprising given the potential implications for geolocation inquiries of cremains (or severely burnt remains) in both forensic and archaeological contexts. This research will focus on the latter context by using strontium isotope analyses, via thermal ionization mass spectrometry, to reconstruct the origins of human remains from a unique late Woodland period (A.D. 600-850) archaeological burial site known as the Perrins Ledge crematory, located in the lower Illinois River valley. Strontium isotope signatures derived from the Perrins Ledge cremains will be compared with values obtained from osteological faunal remains from three contemporary neighboring sites (Carlin, Apple Creek, and Newbridge). It is expected that the Perrins Ledge values will mirror those derived from the neighboring contemporary habitation sites suggesting local groups used the crematorium.