Stable isotope indicators of provenance and demographics in 18th and 19th century North Americans

Using stable isotopes to gain insight into individual life histories is a valuable tool for unidentified or incomplete remains lacking historic records. This study analyzed stable carbon, nitrogen, and oxygen isotopes from bones and teeth of 18th-19th century North Americans of known ancestry, social class, and region of origin in an effort to discern qualitative patterns and create a quantitative predictive model of demographic information. The delta C-13(collagen), delta C-13(structural carbonate), and delta O-18(structural carbonate) values provide the most overall information for detecting demographic differences, with delta N-15(collagen) and delta O-18(phosphate) to a lesser degree. Region of origin was the most predictable demographic factor with 82% correct classifications based on a two-variable model using delta C-13(collagen) and delta O-18(meteoric) water calculated from ebstructural carbonate, which reflects the influence of dominant local vegetation types and local drinking water. Ancestry was correctly identified in 68% of cases using delta C-13(collagen). Social class was less predictable with correct identification in 60% of cases based on delta C-13, delta N-15, and delta O-18 values where the upper class was phate o t most distinguishable. Isotope patterns observed in ancestry and social class groups are linked to cultural food preferences and food availability. Certain sample sites, such as military burials and urban cemeteries, show a greater range of isotope values suggesting a variety of individual regional origins and cultural backgrounds. Burials of extreme upper or lower class individuals show greater isotopic homogeneity suggesting reliance on localized food sources or cultural preferences for particular dietary choices. Published by Elsevier Ltd.