Paleocurrent direction of the Late Cenozoic sedimentary sequence of the Tibetan plateau northwestern margin constrained by AMS and its tectonic implications.
Paleocurrent direction of the Late Cenozoic sedimentary sequence of the Tibetan plateau northwestern margin constrained by AMS and its tectonic implications.
复制标题
作者：
Pei Jun
古水流方向的确定是确定沉积物运移和沉积过程的有力途径。自然沉积和实验室沉积的研究表明，磁化率各向异性作为古水流指示器的可靠性。青藏高原西北缘柯克雅剖面晚新生代地层包括乌恰组、阿图什组和西峪组的80个样品的磁组构研究。样品的Flinn型(F对L)和P‘-T图清楚地表明，所有样品都具有扁平椭球体，表明它们具有原始沉积性质。乌恰组、阿图什组和西峪组的样品均为原始沉积古水流方向的转换可能为晚更新世青藏高原东北部的隆升提供有价值的信息。乌恰组与阿图什组、阿图什组与西域组之间古水流方向的剧烈变化表明，西昆仑山西部的构造抬升早于东部。
The determination of paleocurrent directions is a robust approach to establish the sediments transport and of the deposition progress.The credibility of the Anisotropy of Magnetic Susceptibility(AMS)as a paleocurrent indicator has been known from work on naturally and laboratory deposited sediments.The study of 80 samples magnetic fabric has been developed for the Late Cenozoic strata including Wuqia,A'tushi and Xiyu Formations,Kekeya section of the Tibetan plateau northwestern margin.Flinn-type( F versus L) and P'-T plots of the samples very clearly indicate that all the samples have oblate ellipsoids,suggesting their primary depositional nature.The samples from Wuqia,A'tushi and Xiyu Formations,Kekeya section have been measured,providing AMS data and paleocurrent directions information.The transfer of paleocurrent directions may offer valuable information about uplift of the northeastern Tibetan Plateau during the Late Cenozoic.The dramatic changes in paleocutTent directions between Wuqia and A'tushi, A'tushi and Xiyu Formations imply that the tectonic uplift of the western of the West Kunlun Mountain occurred early than east.