摘要
古流向的确定是重建沉积物来源及沉积过程的有效方法,而磁化率各向异性作为古流向恢复的可靠信息载体在室内沉积实验和具体工作中已得到认可。本文对青藏高原西北缘柯克亚剖面晚新生代地层乌恰群、阿图什组和西域组80块样品开展了磁组构研究,磁面理与磁线理图、磁化率各向异性度与磁化率椭球体形状因子图直观地说明研究对象均具有磁面理较磁线理发育的特点,代表了原生沉积组构特征。柯克亚剖面乌恰群、阿图什组和西域组的磁化率各向异性测量则恢复了三个时期的古流向。古流向在不同时期的变迁显示了重要的青藏高原西北缘的隆升信息。乌恰群与阿图什组、阿图什组与西域组之间的古流向的改变反映出西昆仑山北缘具有西早东晚的构造隆升过程。
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 Susceptibillty（AMS）as a paleoeurrent 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 paleocurrent 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.
出处
《岩石学报》
SCIE
EI
CAS
CSCD
北大核心
2008年第7期1613-1620,共8页
Acta Petrologica Sinica
基金
地质力学所基本科研业务费项目(编号:DZLXJK200811)
中国地质调查局地质调查项目(1212010610105,1212010610108)联合资助的成果
关键词
古流向
磁化率各向异性
晚新生代
西昆仑
隆升
Paleocurrent directions
Anisotropy of Magnetic Susceptibility
Late Cenozoic
West Kunlun Mountain
Uplift
