Neogene eolian deposits within the West Qinling Mountains:Climatic and tectonic implications  

作　　者：GE JunYi 1,2 & GUO ZhengTang 3 1 State Key Laboratory of Loess and Quaternary Geology (SKLLQG),Institute of Earth Environment,Chinese Academy of Sciences,Xi’an 710075,China 2 Graduate University of Chinese Academy of Sciences,Beijing 100049,China 3 Key Laboratory of Cenozoic Geology and Environment,Institute of Geology and Geophysics,Chinese Academy of Sciences,Beijing 100029,China 

出　　处：《Chinese Science Bulletin》2010年第15期1483-1487,共5页

基　　金：supported by the National Natural Science Foundation of China (Grant No. 40730104);the Knowledge Innovation Projects of the Chinese Academy of Sciences (GrantNo. KZCX2- YW-117)

摘　　要：The Qinling Mountains constitute a key climate barrier between southern and northern China.Our recent investigations revealed widely spread eolian deposits of Neogene age mantling the piedmont highlands of the intermountain basins within West Qinling.Micro-mammalian fossils dated a 150.2 m section (NL-VI) near Xihe for the late Miocene to Pliocene (～10-4 Ma).Soil micromorphology,grain-size and geochemical analysis consistently define typical loess-soil alternations for the upper (0-66 m) and lower (98-150.2 m) parts of the section,with the middle section (66-98 m) having been affected by episodic slope erosions.These results add important insights to the earlier studies about the widespread eolian deposition in northern China during the Miocene,prior to 8 Ma.They also suggest that the basic configuration of the ridges and inter-ridge basins of West Qinling has already formed by ～10 Ma.The well-preserved eolian deposits are unlikely to support intense substratum deformation and rapid uplift of West Qinling since the late Miocene.The Qinling Mountains constitute a key climate barrier between southern and northern China.Our recent investigations revealed widely spread eolian deposits of Neogene age mantling the piedmont highlands of the intermountain basins within West Qinling.Micro-mammalian fossils dated a 150.2 m section （NL-VI） near Xihe for the late Miocene to Pliocene （～10-4 Ma）.Soil micromorphology,grain-size and geochemical analysis consistently define typical loess-soil alternations for the upper （0-66 m） and lower （98-150.2 m） parts of the section,with the middle section （66-98 m） having been affected by episodic slope erosions.These results add important insights to the earlier studies about the widespread eolian deposition in northern China during the Miocene,prior to 8 Ma.They also suggest that the basic configuration of the ridges and inter-ridge basins of West Qinling has already formed by ～10 Ma.The well-preserved eolian deposits are unlikely to support intense substratum deformation and rapid uplift of West Qinling since the late Miocene.

关 键 词：秦岭山脉 风尘堆积 构造意义 气候 新近纪 晚中新世 地球化学分析 风尘沉积 

分 类 号：P542[天文地球—构造地质学]