摘要
中生代以来,中国东部(东经102°以东地区)和东亚濒太平洋地区的地质构造格局发生了巨大的变革,形成了一系列北东-北北东向的构造隆起带和沉降带,构成了一个巨型多字型构造,控制着该区中生代以来的沉积建造、岩浆活动、成矿作用以及挽近时期的地势轮廓。李四光把这种独特的构造现象称为新华夏构造体系。
The geotectonic framework of eastern China(to the east of longitude 120 E)has un-dergone a great change since the Mesozoic era.There sprang forth a mighty NE-NNEtrending tectonic system,characteristic of eastern China and the Peri-Pacific Asian Conti-nent which controls the distribution of magmatism,ore formation,earthquakes and even theconfiguration of landforms.It was named by Prof.Li Siguang(J.S.Lee)as the Neoca-thaysian System.An attempt is made in this paper to illustrate the younging of the growth of the Ne-ocathaysiam from west to east and the corresponding progressive change of the temperatureof ore formation and of composition on the basis of sedimentation,magmatism,diastrophism.metamorphism and mineral formation.For the mechanism of the formation of the NE-NNE trending structure zone and thelateral migration with time of the various geological processes,we agree to Prof.Li Sigu-ang’s view that it might result from the shearing due to the southward movement of theAsiatic continent relative to the Pacific which Li attributed to the change of speed of theEarth’s rotation.This shearing would,of necessity,produce a WNW-ESE compression,which,coupled with the southward push of the continent,would cause the overriding ofthe continental crust toward the Pacific.During its forward advance,rocks between thediscontinuities within the crust of eastern China would slide or creep ahead at different ve-locities toward the Pacific,constituting a back downwarp-midrise-front sliding regime.Thefore front,the foremost part of the regime,is an area of stress concentration where occurrelatively strong magmatism,diasrophism,dynamic metamorphism and mineralization.Themidrise lies between the fore front and the back downwarp.The back downwarp is actuallya large depression where sediments were deposited with the lapse of time,the sliding re-gime would tend to move from west to east to form a new sliding regime,thus resulting ina continuous migraton of the continent toward the ocean.This is the picture visualized todepict the growth and development of the Neocathaysian system.
作者
谭忠福
张启富
Tan Zhongfu;Zhang Qifu(Yichang Institute of Geology and Mineral Resources,Chinese Academy of Geological Sciences)
出处
《地质学报》
1983年第1期43-50,108,共9页
Acta Geologica Sinica
