中亚干旱区第四系黄土和干旱环境研究进展

Pleistocene Loess-Paleosol Sequences in Arid Central Asia:State of Art

中亚黄土位于连接欧洲黄土和中国黄土的咽喉地带,黄土地层的古气候记录研究对完整认识地质时期欧亚大陆古气候的演化历史、空间差异和不同时间尺度上的主控因素,深入理解欧亚大陆西风—季风系统的相互作用机制有重要意义。然而,中亚黄土的研究程度与欧洲和中国黄土相比明显偏弱,尤其与中国黄土的对比研究亟待加强。综述了近些年中亚第四系黄土研究的主要进展,基于代表性剖面和中国黄土古气候记录粗框架的对比,讨论了中亚干旱区第四纪以来构造尺度上的干旱化过程,轨道尺度上的干湿变化历史和亚轨道尺度上的干湿变化及其与东亚季风区古气候变化的相位关系。

Loess of central Asia is located in a linkage zone between the European and Chinese loess depositional belts. Paleoclimate signatures from loess-paleosol sequences here is a key for completely understanding the spatial-tempo paleoclimate changes of Euro-Asia and for understanding the interactions between westerlies and Asia monsoon system during geological time. However,paleoclimate investigations of loess-paleosol sequences in arid central Asia is relatively weak than those from Europe and Chinese Loess Plateau. Specific,correlations of paleoclimate records with Chinese loess is required for better understanding 'westerly regimes' in central Asia and its phase relationship with monsoon Asia on various time scale. In this work,we reviewed new advantages of loess study in central Asia during the last decades. Based on the stratigraphic and paleoclimatic correlations of loess-paleosol sequences between central Asia and the Chinese Loess Plateau,we discussed aridification history of Asia on tectonic time scale,the hydroclimate changes in arid central Asia and its phase relationship with Monsoonal Asia on orbital and millennial time scale during the Pleistocene.