Abstract
Orbitally tuned magnetic susceptibility and quartz mean grain size records from Chinese loess-red clay sediments reveal that marine oxygen isotope stratigraphy is in harmony with late Pliocene climate evolution. On the Chinese Loess Plateau, the long-term late Pliocene warm-moist climate since ca. 3.6 Ma, recorded in a red clay layer, was interrupted by a sudden and large cooling-drying event, correlated with the MIS G6—G4 ice-sheet expansion (2.73—2.68 Ma). The climate at the time of the event was still warm. The first loess layer (L33) overlying the red clay is correlated with MIS 104. The L33 glacial episode is characterized by the strongest winter monsoon recorded in the Pliocene—Pleistocene, although the ice volume increase during MIS 104 was relatively small (equivalent to approximately 50 m of sea-level change), being comparable to that in MIS 5.1. The Gauss-Matuyama (GM) transition with multiple rapid polarity swings occurred during the lower to middle part of loess layer L33, which is overlain by paleosol layer S32 and is correlated with MIS 103. The lower boundary of S32 coincides with the beginning of the Quaternary. In the Japanese Islands, the cooling-drying event is correlated with MIS G6 to MIS G4-caused termination of the long-term late Pliocene warm-moist climate, and its accompanying large scale impact on forests. However, the climate during the cooling-drying event was as warm as that during interglacial times.
