Late Pliocene-Pleistocene changes in mass accumulation rates of eolian deposits on the central Chinese Loess Plateau

Abstract

Late Pliocene-Pleistocene changes in the mass accumulation rates (MARs) of eolian deposits on the central Chinese Loess Plateau (CLP) are reconstructed from measured bulk sediment densities combined with sedimentation rates calculated for two loess/red clay sequences. The reconstructed MARs demonstrate that over the past 3600 kyr, distinct aridity-humidity fluctuations occurred over glacial-interglacial timescales, and these were superimposed on a gradual long-term drying trend. Comparisons of the CLP MAR record with the MAR and δ 18 O records for marine sediments suggest that the development of Northern Hemisphere ice sheets since the late Pliocene has played a part in increasing the aridity of central Asia. In addition, the phased uplift of the Himalaya-Tibetan Plateau evidently had a profound influence on the aridity of central Asia; this was mediated by variations in the East Asian monsoonal circulation. Correlations among dust records from ice cores, marine sediments, and terrestrial loess over the last several glacial cycles provide compelling evidence that glacial periods are characterized by higher and more variable dust fluxes than interglacial intervals. Synchronous changes in the MAR, grain size, and δ 18 O records reveal dynamic linkages between Asian interior aridity, paleowind intensity, and ice volume after the onset of major Northern Hemisphere glaciations. Copyright 2005 by the American Geophysical Union.