华南是特提斯多岛洋体系的一部分

SOUTH CHINA DEFINED AS PART OF TETHYAN ARCHIPELAGIC OCEAN SYSTEM

特提斯的多岛洋模式认为，冈瓦纳超大陆与欧亚超大陆的裂解块体群在其漂移过程中，漂移前方的洋盆萎缩、消亡，后方则由裂谷发展为新的洋盆，如此循序出现的洋盆就构成了古、中、新特提斯等不同阶段．裂解、漂移和消亡的多幕次过程，使特提斯与大西洋、太平洋等“干净”的大洋不同．它在其各个演化阶段，始终是个充满着裂解地块与裂谷、海道，微板块与小洋盆，岛弧与边缘海等不同裂离与聚合程度的海陆相间的多岛洋盆．华南是特提斯多岛洋体系的一部分．它由秦岭微板块、扬子板块（含下扬子地块、昌都－思茅地块、义敦地块、松潘－甘孜地块）、华夏板块、滇缅泰马板块（保山）、印支－南海板块（海南岛）组成，与华北板块间及相互间以商丹小洋盆、勉略小洋盆、华南小洋盆及古特提斯洋分开．对扬子板块与华夏板块的关系、秦岭小洋盆与扬子及华北板块的关系、扬子板块西侧的裂解地块及亲冈瓦纳的裂解块体分别作了较详尽的论述．根据这些块体的构造、沉积、古生物、古地磁绘制了它们的古海洋复原图．多岛洋体系板块运动具有软碰撞、多旋回和造山长期性的特点．其板块碰撞通过岛屿或块体增生的多幕次微型碰撞而实现．每一微型碰撞的速度为２个碰撞块体速度的差，而不是速度的和，两碰撞块体的质量总额又是很?

When the rifted blocks of Gondwana and Eurasian supercontinents were drifting, the ocean basin in front of the drifting blocks may have subducted and disappeared, but a new ocean may have developed from a rift valley behind the drifting blocks, as suggested in the Tethyan archipelagic ocean model. The ocean basins that occurred in sequence may have been classified as different stages of the Paleo_, Meso_ and Neo_Tethys. The multi_phase process from the riftogenesis, block drift to subduction may have distinguished the Tethys from such “clean” oceans as the Atlantic Ocean and the Pacific Ocean. In different evolutionary stages of the Tethys, the Tethys has always remained an archipelagic ocean, a mosaic of seas and lands in various degrees of dispersion and integration, for examples, the rifted blocks, rifts and seaways; micro_plates and micro_oceans; island arcs and marginal seas. South China, part of the archipelagic ocean system of Tethys, is composed of the Qinling micro_plate, the Yangtze plate (including the Lower Yangtze block, the Qamdo_Simao block, the Yidun block and the Songpan_Garze block), the Cathaysian plate, the Sibumasu plate (Baoshan) and the Indo_China_South China Sea plate. The South China has been separated from the North China plate and also split into different smaller plates by the Shangxian_Danfeng micro_ocean, the Mianxian_Lueyang micro_ocean, the South China micro_ocean and the Paleo_Tethys ocean. This paper presents the relationship between Yangtze and Cathaysia, the relationship among Qinling, Yangtze and North China, and examines the rifted blocks along the western side of the Yangtze plate, as well as the pro_Gondwana rifted blocks. The paleo_oceanic maps are reconstructed from tectonic, sedimentary, paleontologic and paleomagnetic data. Plate tectonics of the archipelagic ocean system is characterized by soft collison, polycyclicity and orogenic longevity. Its plate collision resulted from multi_phase micro_collision of island or block accretion. The velocity of each micro_collision is a difference between, rather than a sum of, the velocity of two colliding blocks. The total mass of the two colliding blocks is so small that no orogeny may have occurred. This is what we called the “soft collision”. Polycyclicity follows the concept by Huang Jiqing. Each micro_collision is usually ensued by a relaxed or extensional phase. In this sense, the orogeny did not always immediately follow each collision. Sometimes, the orogeny may have been deferred until after 100Ma or longer years, resulting in the longevity of an orogeny.