Taphonomic changes to the buried body in arid environments: an experimental case study in Peru

Abstract

Despite an increasing literature on the decomposition of buried and exposed human remains it is important to recognise that specific microenviron-ments will either trigger, or delay the rate of decomposition. Recent casework in arid regions of the world has indicated a need for a more detailed understanding of the effects of burial over relatively short timescales. The decomposition of buried human remains in the coastal desert of Peru was investigated using pig cadavers (Sus scrofa) as body analogues. The project aims were to specifically examine the early phases of natural mummification and contrast the effects of direct burial in ground with burial in a tomb structure (i.e. with an air void). Temperature was logged at hourly intervals from both the surface, grave fill and core body throughout the experiment. In addition, air temperature and humidity were measured within the air void of the tomb. After two years all three pig graves were excavated, the temperature and humidity data downloaded and the pig carcasses dissected on site to evaluate condition. The results demonstrate that: (1) there were distinct differences in the nature/rate of decomposition according to burial mode; (2) after two years burial the carcasses had been subject to considerable desiccation of the outer tissues while remaining moist in the core; (3) the body had undergone putrefactive change and collapsed leading to slumping of soil within the grave fill following the curvature of the pig's back, although this was not evident from the surface; (4) there was a specific plume of body decomposition products that wicked both horizontally and also vertically from the head wounds in the sandy desert soil. These observations have widespread application for prospection techniques, investigation of clandestine burial, time since deposition and in understanding changes within the burial microenvironment under arid conditions.