Mosslik och kärrskelett : Analys av torv från ett skelett utgrävt vid offersjön Bokaren

Sammanfattning: This paper examines peat that was discovered next to a skeleton dug out in wetlands next to lake Bokaren in Uppland, Sweden, in 2015. The skeleton was that of a man from the Roman Iron Age. It was found in fen peat, where soft tissue decomposes but bones are often well preserved. The elemental composition of the peat was examined using X-ray fluorescence. It was found that the composition of heavy elements was likely a result from exchange between the body and the peat. There were also trace elements, some of which may originate from medicine or other use. There may also be traces of brass. X-ray diffraction however revealed no trace of mineral formation. The lipid content of the peat was examined using Gas Chromatography and Mass Spectrometry. Fatty acids, cholesterol and degradation products expected from a waterlogged, anaerobic environment where discovered. Dark-colored peat surrounding body was found to contain lipids from the body and lipids from the inside of the skull where particularly well preserved. Theoretically, both lipid analysis and XRF could be used to locate bodies in fen peat by sampling. From the lipid analysis, one may draw the conclusion that it was a primary burial and that the body was put in a wet context short time after death. Efforts may have been taken to prevent the body from floating to the surface. The head of the body probably came off during decomposition with soft tissue remaining.