Human and livestock faecal biomarkers at the prehistorical encampment site of Ullafelsen in the Fotsch Valley, Stubai Alps, Austria – potential and limitations

[摘要] The Ullafelsen at 1869 m above sea level (a.s.l.) in the Tyrolean StubaiAlps next to Innsbruck is an important (geo)archeological reference sitefor the Mesolithic period. Buried fireplaces on the Ullafelsen plateau weredated at 10.9 to 9.5 ka cal BP and demonstrate together with thousands offlint stone artifacts the presence of hunter-gatherers during the EarlyHolocene. Grazing livestock has been a predominant anthropozoological impactin the Fotsch Valley presumably since the Bronze Age (4.2–2.8 ka). Inorder to study the human and/or livestock faeces input on the Ullafelsen, wecarried out steroid analyses on 2 modern ruminant faeces samples from cattleand sheep, 37 soil samples from seven archeological soil profiles, and 9soil samples from five non-archeological soil profiles from the FotschValley used as reference sites. The dominance of 5 β -stigmastanol anddeoxycholic acid in modern cattle and sheep faeces can be used as markersfor the input of ruminant faeces in soils. The OAh horizons, which haveaccumulated and developed since the Mesolithic, revealed high contents ofsteroids (sterols, stanols, stanones and bile acids); the eluvial light layer (E (LL)) horizoncoinciding with the Mesolithic living floor is characterized by mediumcontents of steroids. By contrast, the subsoil horizons Bh, Bs and BvCvcontain low contents of faecal biomarkers, indicating that leaching ofsteroids into the podsolic subsoils is not an important factor. High contentof 5 β -stigmastanol and deoxycholic acid in all soil samples givesevidence for faeces input of ruminants. The steroid patterns and ratiosindicate a negligible input of human faeces on the Ullafelsen. Inconclusion, our results reflect a strong faeces input by livestock, ratherthan by humans as found for other Anthrosols such as Amazonian dark earths.Further studies need to focus on the question of the exact timing of faecesdeposition.

[学科分类] 大气科学