华北陆台北缘古生代地质构造特征与演化

NORTHERN MARGIN OF NORTH CHINA PLATFORM WITH CONTRAINTS ON ITS TECTONIC CHARACTERIZATION AND EVOLUTION IN THE PALAEOZOIC PERIOD

早寒武世晚期-奥陶纪华北陆台为陆表海,沉积稳定型建造,蒙古-吉黑洋优地斜继续发展,堆积大洋玄武岩系和岛弧火山岩系。志留纪系蒙古-吉黑洋优地斜沉积复理石建造,对陆台俯冲作用加强,促使陆台隆起剥蚀,缺失志留系-泥盆系。石炭纪一二叠纪蒙古-吉黑洋变为冒地斜,与陆台同时出现北东向隆起和裂陷。三叠纪印支运动使蒙古-吉黑洋封闭,与华北陆台古生代地层同时褶皱隆起,联合组成亚洲陆台。

In the time span between late Early Cambrian and Ordovician,the northern margin of North China plafform was covered with an epicontinental sea,the Mongolia-Helongjiang-Jilin ocean,where ocean basalts and island arc volcanic rocks were accumulated.Entering the period of Silurian to Devonian,the ocean developed a set of flysch sediments which,featuring an eugeocline,more vigorously subducted toward the platform until it was uplifted to suffer from intensive denudation with no depositions the same period.The Carboniferous-Permian times waw the ocean progressively changing into a miogeocline while the plaform itself experienced uplifting and rifting in a northeast direction.By the Triassic period,the megabasin began closing up in the presence of Indosinian movement and at the same time,the Palacozoic cover on the platform was folded to dome,together with the former,inot what is called Asian platform.