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| Titel |
Holocene hydrological changes and human presence in NW Arabia: Insights from lipid biomarker analysis of the Tayma palaeolake sediment record |
| VerfasserIn |
Nadine Dräger, Valérie F. Schwab, Birgit Plessen, Ina Neugebauer, Michèle Dinies, Max Engel, Achim Brauer, Gerd Gleixner |
| Konferenz |
EGU General Assembly 2017
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| Medientyp |
Artikel
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| Sprache |
en
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 19 (2017) |
| Datensatznummer |
250143723
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| Publikation (Nr.) |
 EGU/EGU2017-7473.pdf |
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| Zusammenfassung |
| Holocene hydrological changes in NW Arabia and their influence on human migration and
settlement are scarcely studied due to the lack of suitable climate archives. In particular,
mechanisms and sources of increased moisture availability as well as the onset of oasis
cultivation and culture during the early Holocene humid period are still not well
understood.
Here, we present the first Holocene lipid biomarker record of the Arabian Peninsula from
the Tayma palaeolake sediment sequence. We applied a combined approach of aquatic,
terrestrial and faecal lipid biomarker and compound specific hydrogen isotope analyses,
which allow tracing both hydrological and anthropogenic signals in the sediment deposits.
Our investigations focused on the early Holocene annually laminated (varved) sediment
section (ca. 8500 to 8000 cal. a BP) presenting a phase of maximum lake levels
probably caused by increased moisture availability (Dinies et al., 2015; Engel et al.,
2012).
During the early Holocene high lake level phase our results show increased
concentrations of long-chain n-alkanes and faecal biomarkers suggesting grassland expansion
and probably human occupation. The increase in grassland during this time is further
supported by results from pollen analysis (Dinies et a., 2015). However, the increase in
n-alkanes and faecal biomarkers did not occur simultaneously. While the rise of n-alkane
concentrations predates the onset of varved sediments by about one century, the increase in
faecal biomarker coincides with the beginning of varve preservation. Moreover, comparisons
with sedimentological and geochemical data (i.e. diatom layer thickness, organic carbon
content, δ13Ccarbonate) suggest a coincidence of highest concentrations of faecal
biomarkers and increased lake productivity. We discuss possible causes for these
coincidences including prehistoric human activities as well as climate and environmental
changes.
This study is a contribution to the research project “CLEAR – Holocene Climatic Events
of Northern Arabia” (https://clear2018.wordpress.com/).
Dinies M, Plessen B, Neef R, Kürschner H (2015): When the desert was green: Grassland
expansion during the early Holocene in northwestern Arabia. Quaternary International (382),
293-302.
Engel M, Brückner H, Pint A, Wellbrock K, Ginau A, Voss P, Grottker M, Klasen N,
Frenzel P (2012): The early Holocene humid period in NW Saudi Arabia – Sediments,
microfossils and palaeo-hydrological modelling. Quaternary International (266), 131-141. |
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