从古地磁研究看中国大陆形成与演化过程  

Discussions on Phanerozoic evolution and formation of continental China, based on paleomagnetic studies.

作　　者：黄宝春[1] 周烑秀 朱日祥[1] 

机构地区：[1]中国科学院地质与地球物理研究所岩石圈演化国家重点实验室,北京100029 [2]国土资源部航空物探遥感中心,北京100083

出　　处：《地学前缘》2008年第3期348-359,共12页Earth Science Frontiers

基　　金：国家自然科学杰出青年基金项目(40525013);国家自然科学优秀群体项目(40221402)

摘　　要：古地磁学是进行大陆板块或微板块(地块)运动演化过程和古地理重建的最有效手段之一。近半个世纪以来,通过中外学者艰苦卓绝的努力,在中国大陆上积累了大量的古地磁数据,为中国大陆各主要块体的起源、构造演化和碰撞拼合过程等提供了定量约束。文中根据现代古地磁数据可靠性判别标准,对扬子、华北及塔里木地块显生宙古地磁数据进行了重新分析和筛选,结合拉萨和喜马拉雅地块的古地磁数据,对中国大陆的形成和演化提出了几点认识:(1)古生代中国大陆各主要块体基本位于赤道附近的低纬度地区;早古生代扬子、华北及塔里木地块与东冈瓦纳大陆关系密切;(2)中生代是中国大陆各主要块体发生碰撞和拼合的主要时期;(3)中国大陆主要块体间的碰撞和拼合具有局部首先碰撞、相互旋转、完全拼合、陆内挤压造山和伸展反弹的特点。Paleomagnetism is well known as a method for paleogeographic reconstructions and for the study of kinematical evolution of continental plates or microplates （blocks）. In the past half century, a large amount of paleomagnetic results from China have been published by both domestic and foreign scientists, which have pro- vided abundant quantitative constraints to the origin, tectonic evolution, and collisional processes of the major blocks that form continental China. In this paper, in the light of international criteria for the reliability of paleomagnetic data, we re-analyzed Phanerozoic paleomagnetic data set for the South China, North China, and Tarim blocks. Combined with paleomagnetic data reported from the Lhasa and Himalaya blocks, we put forward some basic ideas on the Phanerozoic evolution and formation of continental China： （1） the major blocks of continental China were mostly located in low latitudes near the paleo-equator during Paleozoic times. The South China, North China, and Tarim blocks are likely to have some affinities with the East Gondwanaland during the Early Paleozoic times; （2） collisions between the major blocks of China mostly occurred and were completed during the Mesozoic; （3） collision process between the major blocks of China generally went through several stages including an initial contact, relative rotation, collision and suturing, intracontinental compression and orogenesis, followed by post-collision extension.

关 键 词：中国大陆 古地磁学 华北地块 扬子地块 塔里木地块 碰撞与拼合 

分 类 号：P318.44[天文地球—固体地球物理学]