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Between 27 and 11 ka ago thick alluvial loess series have been accumulated in the wadis Feiran, Solaf, El Akhdar and Es Sheikh in the central Sinai. The silty sediments alternate with layers of fluvial sand and gravel. The silts contain Miocene globigerina which originate from the Gulf of Suez, - proof for being aeolian. The former distribution of the loess and the special mechanism of sedimentation is reconstructed from sedimentary structures, from some dug out holes and from the profiles of three wells. The sedimentation milieu has been a mixed load river, from where at high water the fine-grained sediments have passed the banks of the river and sedimented under conditions of a stillwater-facies ("overbank fines" and "crevasse splays"). Some of the loess layers show already traces of soil formation. The mineralogy and - especially - the geochemical composition of the loess lead to paleoclimatologic characterizations of the sedimentary environment and soil formation: in the mentioned period between 27 and 11 ka ago the climate has several times changed from semi-humid to semi-arid and fully arid.