New biomarker analyses from Lake Albert, East Africa spanning ~15-9ka show the most extreme, abrupt, multi-stage climate and environmental shifts during the last deglacial transition of anywhere in Africa. Records of hydroclimate expressed in compound specific δD values from terrestrial leaf waxes and a TEX 86 paleotemperature record support multiple stages of pronounced drying and cooling from 13.8 to 11.5ka and demonstrate the dynamic behavior of the low latitude tropics during the deglaciation. The vegetation response, illustrated by compound specific δ 13 C values and fossil pollen records, was an expansion of C 4 grassland when the region was cool and arid. These results advance our understanding of a spatially and temporally complex regional response to global climate forcing, suggesting weakening of the Indian Ocean monsoon at the end of the Pleistocene that coincides with a minor decrease in the rate of the Atlantic Meridional Overturning Circulation (AMOC) and during a time of stepwise cooling in the northern high latitudes.
Bibliographical noteFunding Information:
We thank Ellen Hopmans, Jort Ossebaar, Sarah Grosshuesch, Koushik Dutta, Stephen Clayton, and Geoff Chidlow. Research was funded by grant NA-060-AR4310113 ( NOAA and the EU Seventh Framework Programme ( FP7/2007e2013 )/ ERC grant agreement no. [ 226600 ]. Support also acknowledged from EAOG Grant (to M.B.). Core collection, shipment and curation were supported by NSF grants GB8328X , GB22858 , GB 33310 and BMS-75-034-54 . Commissioner C. E. Tamale-Ssali of the Uganda Geological Survey and Mines Department authorized the field work. John Okedi, Director of EAFFRO, and S.N. Semakula, P.J. Omedo and Peter Karakaba of the Fisheries Department generously shared their space, equipment, and wisdom. The seamanship, stamina and strength of William Karamanyire and Francisco Rwaswire were essential to success of the field work.
© 2014 Elsevier B.V.
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- African paleoclimate
- Compound specific carbon and hydrogen isotopes
- Lake Albert
- Sedimentary molecular biomarkers
- TEX paleotemperature
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