Preservation in Context: Environmental Variability and Bone Diagenesis in Zooarchaeological Assemblages from India

Sreelekha Ravindran* and Sharada Channarayapatna

Understanding the preservation of faunal remains is critical for zooarchaeological research in India, where diverse environmental conditions influence the survival of skeletal material. However, studies examining how ecological variability affects bone diagenesis remain limited. Bone diagenesis refers to post-depositional physical and chemical changes in skeletal remains that alter mineral structure and organic components and compromise the reliability of biomolecular analyses. This study investigates diagenetic alteration in 80 archaeological faunal samples recovered from sites spanning contrasting environmental zones, including high-altitude cold desert, semi-arid, arid, and humid tropical environments. These contexts provide an opportunity to assess how environmental variability influences bone preservation. A multi-analytical approach is employed. Fourier Transform Infrared Spectroscopy (FTIR) is used to assess mineral structure, organic preservation, and crystallinity indices. Powder X-ray Diffraction (PXRD) evaluates changes in bioapatite crystallinity, while X-ray Fluorescence (XRF) determines elemental composition and potential diagenetic enrichment. Preliminary observations suggest that, as anticipated, samples from northern high-altitude regions exhibit relatively good preservation. Interestingly, bones from arid environments also show better preservation than expected. By comparing preservation patterns across ecological contexts, this study provides one of the first comparative assessments of environmental influences on archaeological bone diagenesis in India and offers a framework for evaluating the suitability of faunal remains for biomolecular analyses, including stable isotope studies, ancient DNA, and palaeoproteomics.