Spatially resolved LA-MC-ICPMS strontium isotope microanalysis of archaeological fauna

The analysis of the strontium isotope composition of archaeological materials can provide important information about the mobility of a range of mammals, including humans. The basis of this method is that, prior to any postburial diagenesis, the Sr87/Sr86 ratio of bone and teeth reflects the geological environment from which food and water were sourced while these biominerals were forming. Teeth are particularly amenable to tracing the geographic origins of humans as they mineralize during the first 12–13 years of life (White and Folkens, 2005) and do not subsequently change strontium composition after this time (Schweissing and Grupe, 2003). Strontium isotope analysis can be used to determine if individuals are local or nonlocal by comparison to the isotopic composition in and around their burial location (i.e., Schweissing and Grupe, 2000; Bentley et al., 2007; Conlee et al., 2009). In order to quantify the extent of faunal mobility, the strontium isotope composition of biominerals from fossil samples needs to be compared with a regional map of values obtained either from local faunal material (Price et al., 2002) or from analysis of the bioavailable component of strontium from plants, regolith, or bedrock (Capo et al., 1998).Strontium isotope analysis has been extensively applied to the determination of archaeological mobility, as reviewed by Price et al. (2002), Budd et al. (2004), Bentley (2006), and Montgomery (2010). Although studies of Paleolithic or older archeological material are rare, some have been undertaken on hominins (Sillen et al., 1995, 1998; Richards et al., 2008; Copeland et al., 2011) and faunal material (Horn et al., 1994; Copeland et al., 2010; Britton et al., 2011).Enamel has been shown to be the most favorable material for strontium isotope analysis based on its ability to resist postburial alteration far better than dentine, cement, or bone (Trickett et al., 2003). Enamel of some species grows over extended periods and, when analyzed with microprofiling or laser ablation analysis, can be used to reconstruct comprehensive life histories. This approach demonstrated the seasonal mobility of cattle in Iron Age Britain (Horstwood et al., 2008), Neolithic Germany (Bentley and Knipper, 2005), and England (Viner et al., 2010).

Mobility patterns in inland southwestern Sweden during the Neolithic and Early Bronze Age

In this paper, we investigate population dynamics in the Scandinavian Neolithic and Early Bronze Age in southwestern Sweden. Human mobility patterns in Falbygden were studied by applying strontium isotope analysis combined with archaeological and bioarchaeological data, including mtDNA and sex assessment on a large dataset encompassing 141 individuals from 21 megalithic graves. In combination with other archaeological and anthropological records, we investigated the temporal and spatial scale of individual movement, mobility patterns of specific categories of people and possible social drivers behind them. Our results of strontium and biomolecular analyses suggest that mobility increased in the Late Neolithic and Early Bronze Age compared to the earlier parts of the Neolithic. The data indicate individuals moving both into and away from Falbygden. Mobility patterns and contact networks also shift over time.