Thanatogenic anthrosols: a geoforensic approach to the exploration of the sepolcreto of the Ca' Granda (Milan)

Soil is a dynamic matrix which can rapidly respond to disturbance events, such as the death and the deposition of an organism. Moreover, soil can be considered an archive of data due to its ability to record the traces of disturbance events. Accordingly, the biogeochemical analysis of the geopedological evidence could turn into a valuable tool for the study of decomposition processes. Hence, the aim of the present research is to detect the evidence of material exchange, linked to decomposition, between the bone tissue from two skeletal remains of the Sepolcreto (i.e., burial ground) in the crypt of the Ca’ Granda (Milan, Italy), and the pedosedimentary matrix from the stratigraphic unit US3 in which they were immersed. Both biological and geopedological specimens were analysed using a Scanning Electron Microscope equipped with facility for energy-dispersive spectroscopy (SEM-EDS) which pointed out the presence of a mutual exchange of material between the two substrates, underlying the intensity of the interaction between organisms (even if dead) and the environment in which they are located. The results were also able to lead to the detection of an inedited kind of material, mainly composed of organic matter resulted from the decomposition of human remains and preserved bone and soft tissues, which could be considered for introducing a new type of Anthrosol.