Paleomagnetic result of the Cenozoic volcanic rocks from the Tuoyun Basin,southwest Tien Shan of China and its tectonic

Paleomagnetic study on the Cenozoic volcanic rocks from the Tuoyun Basin of the southwest Tien Shan indicates that most samples could isolate a stable characteristic remanent magnetization with reversed polarity. The positive fold test suggests that the characteristic component is very likely to be a primary magnetization acquired in the formation of rocks. Comparison with the reference Eurasia poles at 60 Ma indicates little or insignificant N-S convergence between the south edge of southwest Tien Shan and Siberia since the onset of the India/Asia collision at the Eocene. Furthermore, the Cretaceous and Tertiary paleomagnetic results suggest that the Tuoyun Basin was subjected to a local clockwise rotation of 20 . -35 . With respect to Eurasia since the Paleocene time, which is probably subsequent to the Cenozoic northward compression of the Pamir arc.

作 者： WANG Yongcheng Huang Baochun ZHU Rixiang LIU Tao   作者單位： Institute of Geology and Geophysics, Chinese Academy of Sciences,Beijing 100029, China  刊 名： 科學通報(英文版)  SCI 英文刊名： CHINESE SCIENCE BULLETIN  年，卷(期)： 2004 49(12)  分類號： P5  關鍵詞： Tuoyun Basin   Cenozoic   paleomagnetism   N-S convergence