Strontium isotopes and concentrations in bioarchaeology – connecting diet and mobility

Strontium isotopes and concentrations have played a crucial role in bioarchaeological research for several decades, offering valuable insights into past human and animal mobility, dietary patterns, and landscape use. These geochemical markers have significantly enhanced our understanding of animal-human-environment interactions and are now considered an essential tool in archaeological science. This paper provides a comprehensive review of the current state-of-the-art methodologies and applications of strontium isotope analysis. The review then explores the construction of biologically available strontium baselines, which are fundamental for accurate provenance and mobility reconstructions. This paper also examines the analytical techniques used for strontium isotope measurements, including thermal ionization mass spectrometry (TIMS) and multi-collector inductively coupled plasma mass spectrometry (MC-ICP-MS), highlighting their respective advantages and challenges. Special attention is given to the necessity of using appropriate reference standards and quality control measures to ensure data reliability and comparability across studies. Finally, this paper explores the expanding potential of integrating multiple strontium-based proxies. Beyond the widely used radiogenic 87 Sr/ 86 Sr ratios, the significance of strontium concentrations ([Sr]), Sr/Ca ratios, and stable strontium isotope fractionation (δ 88 Sr) are discussed as complementary tools. When used together, these parameters can refine interpretations of diet, landscape use, and migration patterns in past populations. By synthesizing recent advances and emerging approaches, this review underscores the evolving role of strontium isotope research in archaeology and more particularly in bioarchaeology, emphasizing its potential to unlock new dimensions of past human and ecological interactions. • Strontium isotopes and concentrations inform mobility and diet. • Establishing robust bioavailable strontium (BASr) baselines is crucial. • Not all samples are suitable for strontium isotope analysis. • It is important to measure both strontium isotope ratios and concentrations. • δ 88 Sr values can further refine reconstructions of past diets.