寒武纪全球板块构造与古地理环境再造  

Reconstruction of Cambrian Global Paleo-plates and Paleogeography

作　　者：周肖贝[1,2] 李江海[1,2] 王洪浩[1,2] 李文山[1,2] 

机构地区：[1]北京大学地球与空间科学学院造山带与地壳演化教育部重点实验室 [2]北京大学石油与天然气研究中心

出　　处：《海相油气地质》2014年第2期1-7,共7页Marine Origin Petroleum Geology

基　　金：国家重点基础研究发展计划"973"项目"中国西部古亚洲洋构造域火山岩油气藏形成的地质背景"(编号:2009CB219302)资助

摘　　要：基于古地磁数据对寒武纪全球古板块进行再造,并叠加更新的寒武纪全球大地构造背景和岩相古地理分布等要素,编制了寒武纪全球古板块再造图、古地理图、全球岩相及烃源岩分布图。寒武纪全球板块以冈瓦纳超大陆、劳伦古陆、西伯利亚板块和波罗的板块为主,多集中位于南半球,冈瓦纳超大陆快速向南漂移,其他板块主要向北漂移,并伴随逆时针旋转。寒武纪整体处于海平面及温度的上升时期,全球板块多为陆表海环境,有利于早寒武世的富有机质沉积,为寒武纪生命大爆发提供了良好条件。但此时气候带梯度不高,干旱气候带广泛分布,下—中寒武统多蒸发盐岩。冈瓦纳超大陆北部主要为碳酸盐岩沉积,南部多为砂岩沉积,东部边缘多火山活动,在中部的西侧边缘地区碳酸盐岩沉积和砂岩沉积物中一般有较好的油气和烃源岩。劳伦古陆沉积具有环带特征,其外侧为碳酸盐岩沉积。西伯利亚板块早—中寒武世主要以巨厚的膏盐岩沉积为主,晚期沉积仅为几百米厚的碳酸盐岩,整体处于被动陆缘沉积的构造背景,这促进了该板块中储层和盖层的发育。波罗的板块纬度相对偏高,主要为砂岩和页岩沉积。The global maps of Cambrian plate tectonics, plaeogeography, lithofaices and source rock distribution are compiled up for reconstructing Cambrian global paleo-plates on the basis of the paleomagnetic data and the updating data of the Cambrian global tectonics, lithofacies paleogeography and source rocks. Cambrian plates can be divided into four parts including Gondwana, Laurentia, Siberia and Baltica. They were generally distributed in the southern hemisphere and drifted northwards with contrarotating rotation except the southwards drifting Gondwana supercontinent. Owing to rising of global sea level eustacy and temperature for a long time during the whole Cambrian, the global plates were generally in epeiric sea environments which promoted the Early Cambrian organic-rich deposits and dominant carbonate deposits and provided good conditions for Cambrian life explosion, which were characterized by low climate zone gradients and widely-distributing drought climate zones that led to Lower and Middle Cambrian evaporate and salt deposits. In Gondwana supercontinent, carbonate deposits were mainly in the north part, sandstone deposits in the south and volcanic activities mainly in the east while good source rocks and petroleum resources were commonly distributed in the carbonate and sandstone deposits along the west margin of the central part. Laurentia was characteristic of band sedimentation, outer of which carbonate deposits existed. Huge evaporate rock deposited in the Siberia plate during the Middle-Lower Cambrian and only a few hundreds meter thickness of carbonate deposits did in the late Cambrian, which improved the development of reservoirs and seals under the setting of passive margin. Sandstone and shale were commonly deposited in Baltica plate at relatively high latitude.

关 键 词：寒武纪 古板块 板块构造 岩相古地理 古地理环境 烃源岩 

分 类 号：P542.4[天文地球—构造地质学] TE121.3[天文地球—地质学]