The hidden archive of historical human inhumations locked within burial soils

The study of soils within an archaeological context is often limited to the examination of landscapes and the environmental impact anthropogenic interactions have on their formation. Similarly, archaeological research into human inhumations has mainly focused on the rituals surrounding death, whilst determining socio-cultural practices and perceptions. The majority of research into the interactions of human interment and its effects on the surrounding soil has been limited to macromorphological investigation and elemental analysis. Historic human burials and their degradation products have not, to date, been investigated with regards to their impact on soil pedogenic processes. This research explores the hypothesis: soils and sediments immediately associated with the decomposition of human interment serve as valuable and under-utilised archaeological record. Grave soils were analysed using micromorphological and associated techniques to aid in the understanding of pedogenic processes and elemental composition of the grave soils incorporating burial remains. The analysis provided a comprehensive inventory of information regarding the archaeological inhumations within the burial soil through the spatial analysis of soil features in relation to the body. The analyses was undertaken on the undisturbed soil samples collected from around both single inhumations at sites in Mechelen, Belgium, Syningthwaite priory, England and South Leith, Edinburgh, and mass grave burials collected from Ridgeway, England and Fromelles, France, with control areas also being sampled, so effects of human decomposition of soil pedogenesis could be studies. Micromorphological analysis identified distinct patterns of pedality and depositional pedofeature development associated with the skull and pelvis sample regions around the burial, whilst also determining differences in pedogenesis to that of the control samples. SEM-EDS inorganic elemental analysis provided mapping of the degradation products emanating from the burials and migrating into the surrounding soil matrix, with elevated levels in depositional pedofeatures and fine material incorporated in all burials investigated, but particularly in soils from the skull and pelvic regions. Micromorphological analysis of soil thin sections from contexts of archaeological human inhumation can aid the detection of degradation products from the burial and identify artefacts derived from pre-burial treatment, some of which are no longer visible to the naked eye.