Abstract. Archaeological research in high mountain regions has gotten a lot more attention since
the discovery of the copper age mummy called “Ötzi” in the Ötztaler
Alps in 1991. In the Tyrolean Stubai Alps, the Mesolithic site Ullafelsen at
1869 m a.s.l. (above sea level) close to the recent upper timberline in the Fotsch Valley
represents, on the one hand, a very important archaeological reference site
and offers, on the other hand, intriguing research questions related to, amongst
others, pedogenesis. Given that no biomarkers and stable isotopes
have been hitherto investigated, we aimed at contributing with respective analyses and
additional radiocarbon dating to a better understanding of the landscape
evolution and pedogenesis on and around the Ullafelsen. Our results for modern vegetation suggest that leaf-wax-derived n-alkanes
allow us to chemotaxonomically distinguish between subalpine deciduous trees
(nC27 predominance) versus (sub)alpine grasses, herbs and dwarf shrubs
(nC29, nC31 and/or nC33 predominance). Except for Juniperus, conifers
produce no or extremely low n-alkane contents. Although no clear vegetation
changes could be inferred from the n-alkane patterns of the investigated soil
profiles, the total n-alkane content (TAC) was developed for the first time
as an unambiguous proxy for distinguishing between buried (= fossil) topsoils
(2Ahb horizons) and humus-enriched subsoils such as Bh horizons of podzols.
Based on this leaf wax proxy, we can rule out that the 2Ahb?/Bh? horizons
under question on the Ullafelsen are buried topsoils as suggested
previously. Dating of the H2O2-pretreated soil samples yielded
14C ages for the podzol Bh horizons ranging from 6.7 to 5.4 cal kyr BP. This is clearly younger than the overlying Mesolithic living floor (LL)
(10.9 to 9.5 cal kyr BP) but pre-dates the assumed intensification of
alpine pasturing from the Bronze Age onwards. Both the LL and the directly
overlying OAh3 horizon yielded black carbon maxima and benzene
polycarboxylic acid patterns reflecting fire-induced human impact during the
Mesolithic. The discrepancy between the Mesolithic charcoal 14C ages
(ages of ≥ 9.5 cal kyr BP) versus the 14C ages obtained for bulk
n-alkanes ranging from 8.2 to 4.9 cal kyr BP suggests that non-alkane-producing conifers predominated the vegetation on and around the Ullafelsen
after the Mesolithic occupation. Only with the anthropo-zoological lowering
of the timberline associated with alpine pasturing since the Neolithic and
especially the Bronze Age has an n-alkane-producing vegetation cover (grasses,
herbs or dwarf shrubs) started to predominate.
Abstract. The Ullafelsen at 1869 m above sea level (a.s.l.) in the Tyrolean Stubai
Alps next to Innsbruck is an important (geo)archeological reference site
for the Mesolithic period. Buried fireplaces on the Ullafelsen plateau were
dated at 10.9 to 9.5 ka cal BP and demonstrate together with thousands of
flint stone artifacts the presence of hunter-gatherers during the Early
Holocene. Grazing livestock has been a predominant anthropozoological impact
in the Fotsch Valley presumably since the Bronze Age (4.2–2.8 ka). In
order to study the human and/or livestock faeces input on the Ullafelsen, we
carried out steroid analyses on 2 modern ruminant faeces samples from cattle
and sheep, 37 soil samples from seven archeological soil profiles, and 9
soil samples from five non-archeological soil profiles from the Fotsch
Valley used as reference sites. The dominance of 5β-stigmastanol and
deoxycholic acid in modern cattle and sheep faeces can be used as markers
for the input of ruminant faeces in soils. The OAh horizons, which have
accumulated and developed since the Mesolithic, revealed high contents of
steroids (sterols, stanols, stanones and bile acids); the eluvial light layer (E (LL)) horizon
coinciding with the Mesolithic living floor is characterized by medium
contents of steroids. By contrast, the subsoil horizons Bh, Bs and BvCv
contain low contents of faecal biomarkers, indicating that leaching of
steroids into the podsolic subsoils is not an important factor. High content
of 5β-stigmastanol and deoxycholic acid in all soil samples gives
evidence for faeces input of ruminants. The steroid patterns and ratios
indicate a negligible input of human faeces on the Ullafelsen. In
conclusion, our results reflect a strong faeces input by livestock, rather
than 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 faeces
deposition.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.