黔东及邻区武陵运动及其地质意义

WULING OROGENY IN EASTERN GUIZHOU AND ITS ADJACENT REGIONS AND ITS GEOLOGICAL SIGNIFICANCE

黔东及邻区武陵运动对该地区影响明显,形成了中、晚元古代地层之间的不整合接触关系。贵州梵净山北及湖南大庸、岳阳、平江地区是武陵运动的构造高位区,向南东方向在平面上出现有规律变化,表现为上覆地层从缺失区至沉积区,接触关系从高角度不整合、低角度不整合至平行不整合,中元古代地层的变形变质程度逐渐减弱;反映出该地区武陵运动的中心位置为贵州梵净山、湖南大庸、岳阳、平江一线,是南华狭窄洋盆萎缩、消亡,扬子古陆与华夏古陆的汇聚碰撞形成华南板块,中元古代该地区洋陆转换历程的具体体现。

The Wuling orogeny made a significant influence in eastern Guizhou and its adjacent regions,as reflected by the appearance of disconformities between middle and upper Proterozoic.It took its most profound expression in northern section of the Fanjing Mountain of Guizhou Province,Dayong,Yueyang and Pingjiang areas of Hunan Province,and left some regular changes on the plane toward southeast： the overlying beds from absence to presence,the contact from high-angle to low-angle and then to parallel disconformities,and metamorphism of middle Proterozoic gradually getting weaker.From the tectonic point of view,the Wuling orogeny,with its central place as stated above,brought about the withdraw and final disappearance of the Southern China ocean basin,the formation of the South China Plate by collision and convergence between Yangtze Oldland and Cathaysia Oldland,and the ocean-continent conversion in the study region during the middle Proterozoic.