侏罗纪地壳转动与中国东部岩石圈转型  

Rotation of the Jurassic crust and transformation of the lithosphere in eastern China

作　　者：万天丰[1] 

机构地区：[1]中国地质大学,北京100083

出　　处：《地质通报》2004年第9期966-972,共7页Geological Bulletin of China

摘　　要：对中国东部侏罗纪时期地壳增厚和岩石圈显著变薄的现象,提出一个新的形成机制假说。基于古地磁和地质学的证据认为,鄂霍次克板块朝西和伊佐奈岐板块朝西北方向运移、俯冲和碰撞,造成西伯利亚东部边缘的强烈构造变形,使东亚大陆地壳产生20°～30°的逆时针转动,形成东亚大陆北部地壳朝西运移,而东亚大陆南部(中国东部)地壳相对向东运移。这种滑移作用使中国东部发生强烈的构造-岩浆活动、地壳增厚,同时也使中国大陆东部的上地壳从大陆型岩石圈地幔滑移到大洋型岩石圈地幔之上,出现岩石圈类型的转变和厚度显著变薄的现象。看来,中国东部岩石圈变薄并不是深部地幔羽或大陆伸展作用的结果。A new hypothesis for explaining crustal thickening and significant lithospheric thinning in the Jurassic in eastern China is proposed. Based on the paleomagnetic and geological evidence, the author considered that westward motion and collision of the Okhotsk plate and northwestward motion, subduction and collision of the Izanagi plate resulted in strong tectonic deformation on the eastern margin of the Siberian plate and caused 20°-30° counterclockwise rotation of eastern Asian continental crust, thus leading to westward motion of crust below the northern part of the East Asian continent and relative eastward motion of crust below the southern part of the East Asian continent (including eastern China). The above-mentioned crustal motion gave rise to strong tectono-magmatism and crustal thickening and also led the upper crust below the continent of eastern China to move from on the lithosphere mantle of continental type to on that of oceanic type, and furthermore, there occurred transformation of the lithosphere and significant thinning of the lithosphere. It seems that the lithospheric thinning of eastern China is not the result of the influence of the deep mantle plume or continental extension.

关 键 词：地壳转动 侏罗纪 岩石圈转型 地壳增厚 构造岩浆事件 中国东部 

分 类 号：P542.4[天文地球—构造地质学]