 |
| Titel |
Reconstruction of Holocene southern African continental climate using biomarkers from salt pan sediments |
| VerfasserIn |
Lukas Belz, Irka Schüller, Achim Wehrmann, Heinz Wilkes |
| Konferenz |
EGU General Assembly 2015
|
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 17 (2015) |
| Datensatznummer |
250107916
|
| Publikation (Nr.) |
 EGU/EGU2015-10282.pdf |
|
|
|
|
|
| Zusammenfassung |
| The climate system of southern Africa is strongly influenced by large scale atmospheric and
marine circulation processes and, therefore, very sensitive to global climate change. Recent
publications provided evidence for strong spatial and temporal climate variability in southern
Africa over the Holocene. It is of major importance to understand the mechanisms driving the
southern African climate system in order to estimate regional implications of current global
change. However, proxy datasets from continental geoarchives especially of the semi-arid
western Kalahari region are still scarce. A main problem is the absence of conventional
continental climatic archives, due to the lack of lacustrine systems. In this study we
are exploring the utility of sediments from western Kalahari salt pans, i.e. local
depressions which are flooded temporarily during rainfall events. Besides the analyses
of basic geochemical bulk parameters including TOC, δ13Corg, TIC, δ13Ccarb,
δ18Ocarb, TN, δ15N, the paleo-climatic approach focuses on reconstruction of local
vegetation assemblages to identify changes in the ecosystem. This is pursued using plant
biomarkers, particularly leaf wax n-alkanes and n-alcohols and their stable carbon and
hydrogen isotopic signatures. Preliminary results show prominent shifts in n-alkane
distribution and δ13C values of the C33 homologue during late Pleistocene and early
Holocene. These shifts correlate to changes of the TOC content. Our data indicate
changes in carbon sources which possibly reflect major environmental changes. |
|
|
|
|
|
|