Holocene palaeoecology of the eastern Sahara; Selima Oasis

作者: C.V. Haynes , C.H. Eyles , L.A. Pavlish , J.C. Ritchie , M. Rybak

DOI: 10.1016/0277-3791(89)90001-2

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摘要: Buried lake sediments and tufa strandlines of Holocene age provide evidence a former in the Selima Oasis depression, northwest Sudan, near hyperarid core eastern Sahara Desert. A 1.6 m section through laminated muds precipitates has been analysed detail, 30 radiocarbon dates, geochemical, sedimentological, diatom pollen analyses indicate that unit dated from approximately 8.4 ka BP to <6 BP, was deposited an environment passed one arid-to-humid-to-arid cycle. The arid episodes, prior subsequent 7 are characterized by high CaCO3 deposition, abundant indicators relatively salinity well developed periphytic communities, spectra dominated desert-grassland indicators. humid period centered on 8 is indicated low organic rich mud Al Si oxide diatoms indicating fresh, deep (20 m) lake, assemblage with maximum values for Sahelo-Sudanian tree taxa suggesting thorn shrub savanna vegetational mosaic. This reconstruction, concordant higher groundwater table precipitation between 9.3 agrees palaeoecological inferences other sites North Africa.

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