| 古特提斯洋的闭合时代的古地磁分析:松潘复理石杂岩形成的构造背景 |
| 点此下载全文 |
| 引用本文：李朋武,高锐,管烨,李秋生.2009.古特提斯洋的闭合时代的古地磁分析:松潘复理石杂岩形成的构造背景[J].地球学报,30(1):39-50. |
| DOI：10.3975/cagsb.2009.01.06 |
| 摘要点击次数: 6963 |
| 全文下载次数: 9487 |
|
| 基金项目:自然科学基金项目“内蒙古中部古亚洲洋最终闭合时代的古地磁研究”(编号：40774026)、中国地质大学(北京)地下信息探测技术与仪器教育部重点实验室开放课题项目(编号：GDL0503) |
|
| 中文摘要:对华南地块、塔里木地块和基墨里大陆(包括保山、缅泰和羌塘地块)进行了古纬度和纬度运移量的对比分析，以确定古特提斯洋盆的闭合时代。结果表明：①保山与华南地块于晚二叠世碰撞，然后继续和华南地块、缅泰地块一起向北漂移，直到晚三叠世，并导致华南地块与华北地块碰撞和秦岭—大别造山带的形成；②羌塘地块与塔里木地块碰撞发生在晚三叠世；古特提斯洋沿着保山地块东缘和羌塘地块北缘的闭合是不同时的，东早西晚；③华南地块向北漂移，可能引起了华南地块西部和东昆仑—柴达木地块南部的古特提斯洋北岸的凹入，这为松潘—甘孜海底扇的发育提供了空间；古特提斯洋闭合引起的俯冲造成了华南地块西部大陆边缘的裂离，也共同为海底扇的发育提供了空间。包括塔里木地块、华南地块、东昆仑—柴达木地块和羌塘地块在内的几个地块的合围，导致了松潘—甘孜地块三角形的构造形状。支持以前的假设：松潘—甘孜三叠纪复理石杂岩的物源来自华北地块南缘或秦岭—大别造山带。 |
| 中文关键词:古地磁 古特提斯 松潘—甘孜地块 |
| |
| Paleomagnetic Constraints on the Closure Time of Paleo-Tethys: Implications for the Tectonic Setting of Formation of Triassic Songpan-Ganzi Flysch Complex |
|
|
| Abstract:A comparative analysis of paleolatitudes and latitudinal displacements was undertaken for the South China Block, Tarim Block and Cimmerian Continent (including Baoshan, Shan-Thai and Qiangtang blocks) by using available paleomagnetic data to determine the closure age of Paleo-Tethys. The results show that ①the Baoshan Block collided with the South China Block in Late Permian, and then continued to drift rapidly northwards together with the South China Block until Late Triassic, resulting in the collision of the South China Block with the North China Block and the formation of the Qinling-Dabie orogenic belt; ②the Qiangtang Block collided with the Tarim Block in Late Triassic. The closure of Paleo-Tethys along the eastern edge of the Baoshan Block and the northern edge of the Qiangtang Block might have been diachronous, becoming younger and younger westward; ③the indentation of northern Paleo-Tethys oceanic bank between western South China Block and southern East Kunlun-Qaidam Block mignt have resulted from the northward drift of the South China Block and the rifting of the continental margin of western South China Block, which was caused by the subduction of the oceanic crust and probably Provided the space for the development of Songpan-Ganzi submarine fan. The enclosure of several blocks, including Tarim, East Kunlun-Qaidam, South China and Qiangtang blocks, results in the triangular tectonic shape of Songpan-Ganzi Block, and supports the hypothesis that the source of Songpan-Ganzi flysch complex is attributed to a large flux of sediments from the Qinling-Dabie orogenic belt. |
| keywords:Paleomagnetism Paleo-Tethys Songpan-Ganzi Block |
| 查看全文 查看/发表评论 下载PDF阅读器 |
