Paleomagnetism of early Paleozoic volcanic rocks from the Beishan area,Gansu of northwest China: Preliminary insight into early Paleozoic kinemics of the Beishan terrane |
| |
Authors: | Baochun Huang Yongcheng Wang Rixiang Zhu Fuqin Zhang |
| |
Institution: | Institute of Geology and Geophysics, Chinese Academy of Sciences ,Beijing 100101 ,China |
| |
Abstract: | We report rock magnetic and paleomagnetic results for Middle Silurian Gongpoquan and Middle Ordovician Huaniushan volcanic samples collected from the Mazongshan and Hongliuyuan areas of Gansu Province, northwest China. The resultsindicate that the main magnetic mineral of the Gongpoquan and Huaniushan volcanic rock is magnetite, and it may remain characteristic remanent magnetization acquired at the time of formation of the rocks. However, with the exception of samples from site go20, most of Middle Ordovician Huaniushan volcanic samples have a very weak nature remanent magnetization, and generally show an erratic demagnetization behavior, which does not allow isolation of characteristic remanent magnetizations from these samples. Comparison of paleomagnetic results obtained from the Beishan area of Gansu with Paleozoic apparent polar wander paths for Tarimand Siberia suggests that the Beishan tarrane, the southern part of the Beishanarea of Gansu beyond the Mingshui-Shipanjin-Xiaohuang- shan zone, and adjacent Tarim block and Siberia plate could not have been connected in their present configuration by the Middle Silurian time. On the other hand, we infer that the early Paleozoic Mingshui-Shipanjin-Xiaohuangshan oceanic basin may open from west to east during period from the Ordovician to Silurian, and the post-Middle Silurian closing of this oceanic basin may result from a progressed eastward scissor-like rotation. |
| |
Keywords: | Beishan area of Gansu Early Paleozoic rock magnetism and paleomagnetism |
本文献已被 万方数据 SpringerLink 等数据库收录! |
| 点击此处可从《中国科学通报(英文版)》浏览原始摘要信息 |
| 点击此处可从《中国科学通报(英文版)》下载免费的PDF全文 |
|