Adipocere withstands 1600 years of fluctuating groundwater levels in soil

Abstract

An extraordinarily well-preserved skeleton of a child, interred in a stone sarcophagus in the Late-Roman era, was discovered in the city of Mainz (Germany) in 1998, covered with a puff pastry-like substance assumed to be adipocere. It is the first time that this substance, which is derived from fat under oxygen-deficient conditions and prevents corpses from decaying, has been discovered on corpses buried under conditions described in the present paper. The body was buried at groundwater level (2.9 m below surface) in a moist zone close to the Rhine that was affected by seasonally fluctuating groundwater levels. The fluctuating groundwater levels would appear to have had an effect on the degradation of the interred body. The discovery of the skeleton gave us an excellent opportunity to examine fatty acid material which had been subjected to prolonged fluctuating aerobic and anaerobic conditions in a moderate environment. The body's fatty acid composition and 13C abundance were determined and compared with modern adipocere values. Element analysis of the stone sarcophagus in which the child was buried provided information on the burial environment. Our findings indicate that fatty material must have been converted into adipocere under anaerobic conditions in periods of high water levels, leaving the material open to decay during periods of low water levels. The fact that the excavated body was still covered with adipocere 1600 years after the burial clearly shows the robustness of the material against decay.