Pleistocene climatic history of East and Central Asia based on paleopedological indicators in loess-paleosol sequences

A micromorphological comparison of the loess-paleosol sequence of the Karamaydan section, Central Asia, with the upper part of the Luochuan section, China, clearly indicates that for the Brunhes chron the sequence at Karamaydan is more detailed than the corresponding section at Luochuan. Single paleosols at Luochuan correspond to pedocomplexes at Karamaydan; for example, S 3 at Luochuan corresponds to PK III and S 4 to PK IV, and both PKs developed in a period longer than one interglacial (about 10(4) years). Some pedocomplexes at Luochuan are represented by more detailed successions at Karamaydan; for example, the S 5 complex at Luochuan corresponds to pedocomplexes V and VI. The loess-paleosol sequence at Karamaydan should therefore be regarded as a key sequence for reconstructing the climatic history of the Brunhes epoch. Correlation with the deep-sea oxygen isotope record of Bassinot et al. which includes an accurate astronomical time scale, allows a detailed chronostratigraphical subdivision of the loess-paleosol sequence in Karamaydan for the Brunhes epoch. The sequence in the central and lower pans of thr Chashmanigar section, also in Central Asia, shows much more pronounced paleosols than the equivalent sequence at Luochuan, although some Ck or Ckm horizons indicate the presence of hiatuses, Nevertheless for this part of the sequence it provides more paleoclimatic detail, with cold dry stages represented by loess and warm humid stages (interglacials) by paleosols, than even the deep-sea cores. (C) 1998 Elsevier Science B.V. All rights reserved.