摘要
大陆造山带大多数形成于弧弧碰撞及其弧后盆地衰缩作用，其古地理格局为多岛海。今日的东南亚是多岛海大地构造的现实模型，其中欧亚大陆和澳大利亚的板块边界位于印度尼西亚的班达—巽它弧以南和西太平洋马里亚纳弧以东。介于前缘弧和欧亚大陆之间的是众多的残余弧和弧后盆地。其中有些盆地仍然是海底扩张的中心，一些是不再活动的海盆，也有些海盆正在遭受挤压作用，而一些海盆则已经完全被弧后衰缩作用所消减。位于这些盆地之间的是残余弧，沉降的残余弧顶部的沉积层序类似于被动陆缘。华南大地构造可用多岛海模式予以解释。华南造山带的大地构造相分析、沉积相分析和古地磁等综合研究结果表明，它们大多数是弧弧碰撞作用所形成的碰撞型造山带，二叠—三叠纪的古地理存在着与东南亚今天类似的多岛海格局。临沧弧和华夏弧可能为华南多岛海的前缘弧，起着与今天欧亚大陆的印度尼西亚弧相类似的作用。多岛海古地理格局可能出现于泥盆纪以后，华南板块发生裂解，所形成的弧后盆地大多数于晚三叠世到早侏罗世发生衰缩。
The continental orogenic belts mostly resulted from arc arc collision and their back arc basin collapse, and usually showed archipelago collage in their paleogeographic characteristics. As a present analogue of archipelago tectonics, the current Southeast Asia took the south of Banda Suntta arc of Indonesia and the east of Mariana arc as the boundary of Eurasia continent and Australia plates. Many residual arcs and back arc basins exist between the frontal arc and Eurasia continent. Some basins remain as the oceanic spreading center, some became non active basins, some are undergoing compressional action whereas some oceanic basins have been completely subducted due to back arc collapse. Residual arcs lie between these basins. The sedimentary sequence at the top of sinking residual arc is similar to that of passive continental margin. This paper suggested that the tectonics of South China can be interpreted reasonably by archipelago model. The multidisciplinary research results, consisting of tectonic facies, sedimentary facies and paleomagnetism, indicated that the majority of the Huanan orogenic belt belong to collision type orogenic belt due to arc arc collision. And the Permian Triassic paleogeographic framework there shows achipelago collage similar to today's Southeast Asia. Lincang arc and Cathaysian arc probably served as the frontal arc of Huanan archipelago, playing the similar role as Indonesian arc in Eurasia continent today. These arc terranes and back arc basins might form an archipelago after Devonian when South China plate split away. These back arc basins mostly experienced collapse from late Triassic to early Jurassic.
出处
《地学前缘》
EI
CAS
CSCD
1998年第A08期95-102,共8页
Earth Science Frontiers
基金
中国科学院"百人计划"
中瑞合作项目
国家自然科学基金
关键词
多岛海型
造山作用
弧后盆地
造山带
印支期
archipelago orogenesis, back arc collapse, remnant arc, back arc basins, Huanan archipelago
