题目：特提斯构造域中-东段多陆块单向裂解过程的古地磁制约研究

依托单位：北京大学

项目批准号：92055205

摘要：

精细重建特提斯域多陆块单向裂解-聚合过程对深入探讨地球圈层相互作用和板块动力学机制等具 有重大科学意义。本申请直接瞄准重大研究计划年度重点支持研究方向“特提斯构造域大陆裂解-汇聚 过程精细重建”，本着有限目标，重点突出的原则，聚焦特提斯中-东段多陆块与冈瓦纳大陆间的古位 置变迁，拟通过华南、印支陆块古生代中期，伊朗、拉萨和滇缅泰陆块二叠纪-早三叠世古地磁学研究 ，集成上述陆块及南/北羌塘、华北、塔里木等在内的基梅里和东亚陆块群的可靠古地磁、古生物地理 数据等，利用GPLATES软件重建其~420-200Ma期间的精细运动学图像，厘定华南、印支、伊朗、拉萨、 滇缅泰等陆块从冈瓦纳大陆北缘裂解的时限和过程;精细重建古、新特提斯洋的打开和扩张过程，为 重大研究计划关键科学问题的解决和总体科学目标的实现做出应有贡献。本申请境内外并重、国际合 作背景良好、研究基础厚实，有望在“多陆块单向裂解-聚合过程”上取得突破。

关键词:特提斯构造域;单向裂解;古地磁学;东亚陆块群和基梅里陆块群 ;古生代中-晚期

Abstract:

A detailed reconstruction of the one-way rifting and aggregation process of multi- micro-continents or blocks in the Tethys Tectonic Domain is of great scientific significance for further exploring the interaction of the Earth's spheres and the mechanism of plate dynamics. This proposal aims directly at one of the annual key funding research directions of the major research project, "Detailed Reconstruction of Continental Rifting and Convergence Process in the Tethys Tectonic Domain". Focusing on the paleogeographic location and motion of multi- micro-continents or blocks in the Tethys Domain, we propose to carry out a paleomagnetic study on mid-Paleozoic rocks of the South China and Indochina blocks, and Permian to Early Triassic rocks of the Iran, Lhasa, and Sibumasu blocks. With integration of available paleomagnetic and paleobiogeographic data from the Cimmerian blocks and East Asian blocks including the above mentioned micro-continents or blocks as well as the Southern and Northern Qiangtang, the North China and the Tarim blocks, detailed paleogeographic kinematic images of these micro-continents or blocks during the period spanning from the mid-Paleozoic to Triassic times (420 to 200 Ma) will be reconstructed using the GPLATES paleogeographic reconstruction software. Furthermore, these detailed paleogeographic kinematic images will be used to accurately determine two key scientific issues of the Tethys Tectonic Domain: (i) when and how the South China Block as well as the Indochina Block rifted from the northern margin of the Gondwana continent resulting the opening of the Paleo-Tethys Ocean; and (ii) when and how the Cimmerian blocks including the Iran, the Southern and Northern Qiangtang, the Lhasa, and the Sibumasu blocks separated from the northern margin of the Gondwana continent resulting the opening of the Neo-Tethys Ocean and the subduction of the Paleo-Tethys Ocean. We believe that this proposal will contribute to the solution of the key scientific problems and finally to the realization of the overall scientific objectives of the major research project. In a word, this proposed project focuses both on national and international issues; in the light of our good background of international cooperation and a solid accumulation in paleomagnetism applied to tectonics, it is expected to make a breakthrough on the key scientific issue of "One-way Rifting and Aggregation Process of Multi- Micro-continents or Blocks".

Keywords: Tethys tectonic domain; Unidirectional breakoff; paleomagnetism; East Asian blocks and Cimmerian blocks; Middle and late Paleozoic

主要参加人：

黄宝春，1966.4，男，教授，北京大学，项目负责人

易治宇，1979.11，男，副教授，中山大学，主要参加人

闫永刚，1988.9，男，副教授，中山大学，主要参加人