权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

Paleomagnetic study on evolution of Qinling orogenic belt

秦岭造山带演化的古地磁研究

基本信息

批准号：
02045022
负责人：
YASUKAWA Katsumi
金额：
$ 3.84万
依托单位：
Kobe University
依托单位国家：
日本
项目类别：
Grant-in-Aid for international Scientific Research
财政年份：
1990
资助国家：
日本
起止时间：
1990 至 1992
项目状态：
已结题

项目摘要

In order to clarify the tectonic development of China, palaeomagnetic studies have been done these three years. More than 1,000 oriented rock-core samples were collected from the North and the South China Block and also the Qinling Fold Belt area between them. Almost all the formations, from which the samples were collected, belong to the Palaeozoic era but Mesozoic and a few are Precambrian. The results obtained by the palaeomagnetic analyses show the following facts :(1) The mean latitudes of the North China Block, the South China Block and the Proto-Qinling Belt in Cambrian time are 0.4ﾟS, 17.0ﾟS and 5.5ﾟS respectively.(2) The collision of the South China Block against the North China Block occurred at the eastern end of the boundary between these blocks and the connection between both Blocks progressed toward the west in company with the 60ﾟ clockwise rotation of the South China Block to the North China Block.(3) The accretion of the South China Block to the North China Block took place in early Triassic.(4) The accretion of the Proto-Qinling Fold Belt to the North China Block had finished before the Cambrian, so they have drifted northward as one united body during whole Phanerozoic time.(5) The subducting motion of the South China Block under the Proto-Qinling Belt began in the Cambrian time and finished in the Triassic time.

为了弄清中国大地构造的发展，近三年来开展了古地磁研究。在华北地块和华南地块之间的秦岭褶皱带地区采集了1,000多个定向岩心样品。几乎所有的地层，其中的样品被收集，属于古生代，但中生代和少数是前寒武纪。古地磁分析结果表明：（1）华北地块、华南地块和原秦岭带在寒武纪时的平均纬度分别为0.4 ° S、17.0 ° S和5.5 ° S; (2)华南陆块与华北陆块的碰撞发生在两块边界的东端，随着华南陆块向华北陆块顺时针旋转60 °，两块的连接向西推进。(3)早三叠世华南陆块向华北陆块的增生作用。(4)早在寒武纪以前，原秦岭褶皱带与华北陆块的增生作用就已经完成，因此在整个中生代，它们作为一个整体向北漂移。(5)华南陆块向原秦岭俯冲运动始于寒武纪，结束于三叠纪。