A major reorganization of Asian climate by the early Miocene

作者：Zhengtang Guo, Bainian Sun, Zhongshi Zhang, Shuyang Peng, Guoqiao Xiao, Junyi Ge, Qingzhen Hao, Ying Qiao, Meiyan Liang, Jianfang Liu, Qiuzhen Yin, J. J. Wei · 发表于：Climate of the past · 年份：2008 · DOI：10.5194/cp-4-153-2008 · 被引用次数：630 · 研究领域：Geology and Paleoclimatology Research、Paleontology and Stratigraphy of Fossils、Geological and Geophysical Studies

Abstract. The global climate system experienced a series of drastic changes during the Cenozoic. In Asia, these include the climate transformation from a zonal pattern to a monsoon-dominated pattern, the disappearance of typical subtropical aridity, and the onset of inland deserts. Despite major advances in the last two decades in characterizing and understanding these climate phenomena, disagreements persist relative to the timing, behaviors and underlying causes. This paper addresses these issues mainly based on two lines of evidence. First, we compiled newly collected data from geological indicators of the Cenozoic environment in China as paleoenvironmental maps of ten intervals. In confirming the earlier observation that a zonal climate pattern was transformed into a monsoonal one, the maps within the Miocene indicate that this change was achieved by the early Miocene, roughly consistent with the onset of loess deposition in China. Although a monsoon-like regime would have existed in the Eocene, it was restricted to tropical-subtropical regions. The latitudinal oscillations of the climate zones during the Paleogene are likely attributable to the imbalance in evolution of polar ice-sheets between the two hemispheres. Secondly, we examine the relevant depositional and soil forming processes of the Miocene loess-soil sequences to determine the circulation characteristics with emphasis on the early Miocene. Continuous eolian deposition in the middle reaches of the Yellow Rive...