中国大陆岩石圈的形成、演化与特征

Formation,Evolution and Characteristics of China Continental Lithosphere

中国大陆岩石圈是由37个以上的小地块所组成的,各地块统一结晶基底的形成时期各不相同。它们从元古宙到新生代一直在运移、变位:古生代处在以离散为主的状态,都位于特提斯洋内;古生代晚期、中生代与新生代则为逐渐聚合的过程,最后就汇聚成现在的中国大陆岩石圈。在周边板块运动的影响下,中国中部与西北部形成基本正常的大陆岩石圈,东部在侏罗纪以来则形成具有陆壳洋幔型的、较薄的岩石圈,而西南部的青藏地区形成陆壳增厚型岩石圈。中国大陆岩石圈内部可以发生多圈层的滑脱作用,除岩石圈底面的滑脱作用之外,还可以在莫霍面与中地壳低速高导层等界面发生滑脱,使岩石圈的内部结构变得十分复杂,并由此派生出较强的构造变形、岩浆活动与内生成矿作用。针对中国大陆岩石圈的特殊性,深入研究岩石圈演化的具体特征,具有十分重大的理论意义与实用价值,也可进一步丰富和发展全球板块构造学说。

The China continental lithosphere is composed of over 37 small blocks,the formation periods of which are different.Those blocks migrated from Proterozoic to Cenozoic,and dispersed mainly during Paleozoic in Tethys Ocean.They converged gradually during Mesozoic and Cenozoic,and at last formed recent China continental lithosphere.By being influenced on migration of surrounding plates,the normal continental lithosphere formed in middle and northwestern China,the thinner lithosphere with the type of continental crust and oceanic lithosphere mantle occurred since Jurassic,and there is the lithosphere with thicker crust type at southwest China,i.e.,Tibet and Qinhai areas.There are many detachments in China continental lithosphere.Besides detachment of lithosphere bottom,the detachments are occurred at Moho discontinuity and middle crust,thus the inner structure of lithosphere is more complex,which caused the stronger deformation,magmatism and many metallic ores.Due to the particularity of China continental lithosphere,the characteristics research of lithosphere evolution is provided with the very important value for theory and practical,and also can develop the plate tectonic theory.