Sedimentation changes in a complete Holocene lacustrine record in the Sahara: Varve thickness, seasonality and event layers – Problems of identification, interpretation and chronology.
Abstract
Lake Yoa (19.03°N, 20.31°E, 380 m a.s.l.) is a groundwater-fed lake in the hyperarid
eastern Sahara halfway between the Tibesti Mountains and the Ennedi plateau.
Kröpelin et al. (2008) revealed that the bottom sediments contain a unique archive of
climatic and environmental change in the Earth´s major desert. The 7.5 m sediment
record of OUNIK03/04 which covers 6,100 years has been extended to a maximum
drill depth of 15.7 m during a 2010 coring campaign within the framework of the
Collaborative Research Center (CRC) 806 “Our Way to Europe - Culture-
Environment Interaction and Human Mobility in the Late Quaternary”. The long core
(Co1240) contains the first complete terrestrial record of climate variations from the
onset of the early Holocene humid period to the present. Sediments mainly consist of
fine to very fine laminae in the millimeter to sub-millimeter range and bedded layers
up to 2 cm in thickness. They expose shifts in thickness but also changes in clastic
and geochemical composition. These differences and the occurrence of a few event
layers in the lower part implicate significant changes during lake basin evolution as
well as problems in varve counting. Here we present our interpretation of varve
formation in Lake Yoa and an initial varve chronology in combination with 14C ages
including an overview on applied methods and their usefulness with the Co1240
record.
Bibliography
Kröpelin, S., Karls, J., Kuper, J., Melles, M. (2012): Sedimentation changes in a complete Holocene lacustrine record in the Sahara: varve thickness, seasonality and event layers - Problems of identification, interpretation and chronology. In: Zolitschka, B. (ed.) 3rd Workshop of the PAGES Varves Working Group, Manderscheid, Germany, March 20-25, 2012, Program and Abstracts, Terra Nostra 2012/1: 51
| author | Kröpelin, S. and Karls, J. and Kuper, J. and Melles, M. |
|---|---|
| booktitle | 3rd Workshop of the PAGES Varves Working Group |
| citation | Kröpelin, S., Karls, J., Kuper, J., Melles, M. (2012): Sedimentation changes in a complete Holocene lacustrine record in the Sahara: varve thickness, seasonality and event layers - Problems of identification, interpretation and chronology. In: Zolitschka, B. (ed.) 3rd Workshop of the PAGES Varves Working Group, Manderscheid, Germany, March 20-25, 2012, Program and Abstracts, Terra Nostra 2012/1: 51 |
| key | S.Kröpelin2012 |
| organization | Schriften der GeoUnion Alfred-Wegener-Stiftung |
| pages | 51 |
| publisher | GeoUnion Alfred-Wegener-Stiftung |
| series | Terra Nostra |
| type | conference |
| url | http://pages-igbp.org/products/meeting-products/1048-3rd-varves-working-group-workshop-abstract-volume |
| volume | 2012/1 |
| year | 2012 |