Late Cenozoic magnetic polarity stratigraphy in the Jiudong Basin,northern Qilian Mountain  

作　　者：赵志军 方小敏 李吉均 

出　　处：《Science China Earth Sciences》2001年第S1期243-250,共8页中国科学（地球科学英文版）

基　　金：the National Key Basic Research Development Project (Grant No. G1998040809).

摘　　要：Late Cenozoic sediments in the Hexi Corridor, foreland depression of the Qilian Mountain preserved reliable records on the evolution of the Northern Tibetan Plateau. Detailed magnetic polarity dating on a 1150 m section at Wenshushan anticline in the Jiudong Basin, west of Hexi Corridor finds that the ages of the Getanggou Formation, Niugetao Formation and Yumen Conglomerate are>11-8.6 Ma, 8.6-4.5 Ma and 4.5-0.9 Ma respectively. Accompanying sedimentary analysis on the same section suggests that the northern Tibetan Plateau might begin gradual uplift since 8.6-7.6 Ma, earlier than the northeastern Tibetan Plateau but does not suppose that the plateau has reached its maximum elevation at that time. The commencement of the Yumen Conglomerate indicates the intensive tectonic uplift since about 4.5 Ma.Late Cenozoic sediments in the Hexi Corridor, foreland depression of the Qilian Mountain preserved reliable records on the evolution of the Northern Tibetan Plateau. Detailed magnetic polarity dating on a 1150 m section at Wenshushan anticline in the Jiudong Basin, west of Hexi Corridor finds that the ages of the Getanggou Formation, Niugetao Formation and Yumen Conglomerate are>11-8.6 Ma, 8.6-4.5 Ma and 4.5-0.9 Ma respectively. Accompanying sedimentary analysis on the same section suggests that the northern Tibetan Plateau might begin gradual uplift since 8.6-7.6 Ma, earlier than the northeastern Tibetan Plateau but does not suppose that the plateau has reached its maximum elevation at that time. The commencement of the Yumen Conglomerate indicates the intensive tectonic uplift since about 4.5 Ma.

关 键 词：Hexi CORRIDOR PALEOMAGNETIC STRATIGRAPHY TIBETAN Plateau uplift. 

分 类 号：P539[天文地球—古生物学与地层学]