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显生宙中国大地构造演化的古地磁研究
PALEOMAGNETIC RESEARCH ON THE PHANEROZOIC TECTONIC EVOLUTION OF CHINA
【摘要】 根据古地磁数据可靠性的试用判据,对华北、杨子、塔里木中国三大稳定地块显生宙的构造古地磁数据做了初步检验,考虑古极点的密集区,选用229个古极点以“世”或“纪”为单位进行统计,获得三大稳定地块显生宙综合古地磁视极移曲线。以此为基本依据,结合地质构造、古生物和全球古地理重建图的综合分析,初步探讨了三大稳定地块运动演化的大致轮廓,华北、杨子、塔里木地块碰撞、拼接时限和方式以及华北地块与西伯利亚板块运动演化的关系。
【Abstract】 Synthetic Phanerozoic appanent polar wander paths for the North China,Yangtze andTarim blocks are obtained by averaging paleopoles distributed in a small area for a defined geolog-ical time of a block.This area contains not only most of higher quality paleopoles but also somelower ones.Base on the synthetic APW paths and considering tectonics,paleontology and global geo-graphical reconstruction,we suggest that the North China,Yangtze and Tarim blocks were lo-cated along the lower paleolatitudes near the Eastern Gandwana during the Cambrian,With theclockwise rotation of global main continents in the Paleozoic,the Gandwana moved southwardsto the middle-high paleolatitutes of the southern hemisphere and three stable blocks of Chinawere separated in turn form Eastern Gandwana. In the Late Paleozoic these blocks and terraneswith Cathavsian flora were located on tropical or relatively low paleolatitudes. Clearly,they be-long neither to Gandwana nor to Laurassia. Rather they might be distributed in the middleTethys as an independent assemblage.The collision and weld of the three blocks of China took place from the latest Permian to thelate Jurassic. North China and Mongolian blocks had joined by the Permian before they accretedto Siberian plate. This accretion did not take place until the Cretaceous,when the basic frame-work of Eurasia was formed.
【Key words】 :Paleomagnetism; Geotectonics; Structural evolution; Phanerozoic APW paths;
- 【文献出处】 地震地质 ,SEISMOLOGY AND GEOLOGY , 编辑部邮箱 ,1995年01期
- 【分类号】P318.44
- 【被引频次】50
- 【下载频次】355