Aeolian sedimentation in arid and semi-arid environments of Western Mongolia Jörg Grunert a & Frank Lehmkuhl b a Geographisches Institut der Universität Mainz, Becherweg 21, D-55128 Mainz, Germany b Geographisches Institut der RWTH Aachen, D-52056 Aachen, Germany Summary Research on aeolian sediments in Mongolia shows two main cycles of aeolian sedimentation: first the accumulation of major sand fields neighbouring the eastern bank of rivers and lakes, and second the distribution of loess-like sediments on the mountain slopes. The first is resulting from strong westerly winds, being more strength especially during the glacial periods. The latter is resulting in the erosion and accumulation of silt in this region in more humid periods in Interstadial stages and at the end of glacial periods. Both cycles are described on the case study area of the Uvs Nuur Basin in Western Mongolia. 1 Introduction This paper presents details on sand dunes and on loess-like sediments in the area of the Mongolian Altai in western Mongolia and its Late Quaternary evolution. Concerning aeolian processes in Central Asia, there is a considerable literature on Werner Smykatz-Kloss and Peter Felix-Henningsen (Eds.): LNES 102, pp. 195–218, 2004. c Springer-Verlag Berlin Heidelberg 2004