Paleomagnetism of Miocene sediments from the Turfan Basin,Northwest China:no significant vertical-axis rotation during Neotectonic compression within the Tian Shan Range,Central Asia
会议名称：《中国科学院地质与地球物理研究所2004学术年会》
会议日期：2004年
学科分类：070904[理学-构造地质学] 070801[理学-固体地球物理学] 0709[理学-地质学] 07[理学] 0708[理学-地球物理学]
基 金：supported by the National Nature Science Foundation of China(No.40172081, 40221402) the Ministry of Science and Technology of China(No.2002CCA05100)
关 键 词：Turfan Basin Tian Shan Miocene Paleomagnetism Inclination shallowing Vertical-axis rotation
摘 要：Paleomagnetic results are reported from 377 samples of Miocene red sediments in the Turfan Basin of East Tian Shah, Northwest *** demagnetization for most specimens isolates a low-temperature component that groups around the present geomagnetic field.A high-temperature characteristic component is isolated from four localities and interpreted as primary remanent magnetization from apparent pre-folding origin and positive reversal *** for previous results obtained from Tertiary rocks in central Asia,the magnetic inclination is significantly shallower than the reference field computed from the Eurasian APW path at 10 and 20 *** susceptibility measured in 324 specimens exhibits low anisotropy of less than 1.05 for80%of the *** low anisotropy degrees,AMS shape and orientations suggest that the studied rocks are unlikely to have undergone significant strain during compaction or *** argue that the shallow inclination is likely to result from an initially shallow detrital remanent *** of the paleomagnetic declination from Eurasia, North China,and Tarim suggests that the Turfan Basin has been subjected to little or no vertical-axis rotation since the Miocene. Together with paleomagnetic declinations on both sides of the Talas-Ferghana fault,we propose that the Tian Shan to the east of the Talas-Ferghana fault has remained relatively stationary with respect to adjacent blocks since the Miocene.