华南陆域内古特提斯形迹、二叠纪造山作用和互换构造域的东延  

PALEOTETHYS IN SOUTH CHINA,PERMIAN OROGENY AND THE EASTWARDS EXTENSION OF INTERCHANGE DOMAIN

作　　者：马文璞[1] 

机构地区：[1]中国地质大学

出　　处：《地质科学》1996年第2期105-113,共9页Chinese Journal of Geology(Scientia Geologica Sinica)

基　　金：国家自然科学基金;中国科学院岩石圈开放实验室资助

摘　　要：华南大陆由扬子克拉通和华夏陆块拼合而成，后者具有滇缅泰马（Ｓｉｂｕｍａｓｕ）、印支等互换构造域内诸地块共同的特点。古特提斯洋的一个分支从两广—浙闽东部通过，沟通了以西越南黑水河（ＳｏｎｇＤａ）带和以东环太平洋晚古生代大洋亲缘诸地体。这个分支始于华南中泥盆世的陆内裂陷作用，古生代末扩展成广海。晚二叠世的龙潭组含煤地层和钦防地区的放射虫硅质岩分别代表浅水台地和远海盆地两个不同地形台阶的沉积，中间隔着一个向南倾斜的大陆斜坡。东吴运动在两广交界地区产生磨拉石、混杂堆积，并伴生六万大山等Ｓ型花岗岩基，代表云开地块向北的拼贴。类似事件在闽浙东部可能一直持续到晚中生代。outh China continent was formed by the collage of Yangtze Craton and Cathaysia block,the latter shares some common features with the blocks in Paleotethyan multi-islands ocean like indochina, Sibumasu and Lhasa etc., such as lack of Sinian tillites, the limit between basement and cover is located within Cambrian, and many deformation events in early Paleozoic. Instead of conven-tional concept of post-Caledonian platform in South China, a series of evidence reveals that a branch of Paleotethyan ocean passed through the interior of the continent, liking the Song Da belt of Vietnam in the west with the late-Paleozoic Tethyan fauna-bearing oceanic affinity terrains in Asian margin like Akiyoshi seamount and Yanji terrane in the east.Qinfang trough extending from coast of northeastern Vietnam through Guangh to northern Guangdong is the west segment of Paleotethys, where dark thin bedded Radiolaria sillcalites ranging from late Devoaian to mid-Permian are associated with Mn, Ni, Co deposits but lack of terrigenous elastic layer. Eastwards along the strike of silicalites zone, there are blocks of Devonian pillow lava in late Paleozoic melange. Qinfang through separated northern platform, represented by extensive coal-bearing Longtan Formation, by a south-facing continental slope where mid-Perminan flysch appeared. The features of eastern Paleotethyan segment include Carbonifeous-Permian Radiolaria cherts among the ophiolite suite in northeastern Jingxi, which previously have been considered as Proterozoic age, the melange of southern Zhejiang, which contains Permian coal-beaing rocks and marble, and the late Permian to early Triassic turbitite and contourite in Fujian. Intense Mesozoic thin-skinned thrusting have made them dissembered. Late Permian coarse molasse every-where unconformable covers the silicalites in Qinfang area indicating the Paleotethyan close time in South China, large-scale S-type granitoid batholiths were emplaeced about the same time.

关 键 词：古特提斯 华南 二叠纪 造山作用 互换构造域 

分 类 号：P542.2[天文地球—构造地质学] P534.46[天文地球—地质学]