中国新元古代大陆拼合与Rodinia超大陆

NEOPROTEROZOIC CONTINENTAL BLOCK COLLAGE OF CHINA AND RODINIA SUPERCONTINENT

在对前人研究成果分析的基础上，结合对中祁连地块前寒武纪基底的研究，认为新元古代（１０００～９００Ｍａ）中国各主要克拉通地块（包括华夏地块、扬子地块、华北地块、阿拉善—祁连—柴达木地块、塔里木地块）曾经通过晋宁期碰撞拼合带发生过一次全面的多块体复杂拼贴。这次拼贴过程是全球性新元古代格林威尔碰撞造山作用和Ｒｏｄｉｎｉａ超大陆形成过程的一个组成部分。新元古代拼合的古中国地块在当时位于Ｒｏｄｉｎｉａ超大陆中北部澳大利亚、劳伦提亚和西伯利亚克拉通地块之间。中国的各主要克拉通地块只不过是巨型格林威尔碰撞带之中夹裹的一些小型地块，且都处于新元古代晚期Ｒｏｄｉｎｉａ超大陆破裂的中心部位，这些正是中国大陆上克拉通地块活动性大的早期地质背景。

Investigation of the Meso Neoproterozoic collage and rifting of craton blocks in China continent is vital to the reconstruction of global Neoproterozoic Rodinia supercontinent However, the collage configuration of the blocks in China continent during Meso Neoproterozoic era, the position of these blocks in the Rodinia supercontinent are still open to discussion Based on the available literatures and data about the Meso Neoproterozoic tectonic framework of China,as well as the results of our recent study on the proterozoic basement in eastern Mid Qilian massif, the authors will try to analyze the problems mentioned above in a comprehensive way The blocks distributed in the China continent mainly include Cathaysia, Yangtze, North China, Alashan Qilan Caidam, and Tarim block The 900Ma collional collage zone between the Cathysia and Yangtze block has been recognized by Chinese geologists,although the Jinningian collisional zone between North China and Yangtze block is still disputed Based upon the existence of 1000 ～900Ma ophiolite suite and collisional granite belts, occurrence of a large amount of 1000 ～800Ma tectono thermal event data, intensive and common Jinningian deformation in the Proterozoic basement scattered within the Qinling orogenic belt, we sugget that North China block had collided with the Yangtze block. Although the collage configuration of the blocks in western China is unclear, recognition of the Jinningian collisional zone in the western margin of Yangtze block, preservation of the 900Ma collision zone in the eastern Mid Qilian massif and the eclogite zone in the north margin of Caidam block all suggest that the blocks in Western China had collided with each other during Jinningian period Furthermore the Sinicanearly Paleozoic sediments covered on the Cathaysia, Yangtze, Caidam, and Tarim blocks have the same features, such as the Sinican glacial bed, similar sedimentary facies and sequences, and Gondwana biota, which all imply that these blocks were still a unified collage block at the beginning of the rifting of Rodinia Supercontinent Based on the above analysis, we believe that the Cathaysia block, Yangtze block, North China block, Alashan Qilian Caidam block and Tarim block collaged with each other through the Jinningian collision zones during the early Neoproterozoic ( 1000 ～900Ma), forming a Jinningian unified Sinican block This collisional collage may represent a part of the global Grenvillian orogenic events and the assemblage of Neoproterozoic Rodinia supercontinent Futhermore, we suggest that the early Neoproterozoic collaged unified Sinican block was probably situated in the central northern part of Rodinia supercontinent and between Laurentia, Siberia and Australia blocks, and that major cration blocks of China were only several small craton blocks engulfed in the global mega Grenvillian orogenic belts and were also situated in central part of the broken late Neoproterozoic Rodinia supercontinent