晚古生代泛大陆聚合的全球构造背景：板块漩涡运动轨迹含义的探讨  

Global Tectonic Setting during the Late Paleozoic Convergence of Pangea:Discussion of Plate Vortex Trajectory

作　　者：李江海[1,2] 李维波[1,2] 王洪浩[1,2] 毛翔[1,2] 杨静懿[1,2] 傅臣建[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,北京100871 [2]北京大学石油与天然气研究中心,北京100871

出　　处：《地质学报》2014年第6期980-991,共12页Acta Geologica Sinica

基　　金：国家重点基础研究发展计划“973”项目(编号:2009CB219302)资助的成果

摘　　要：板块构造理论形成以来,不同板块之间的相对作用得到深入阐述,但对多板块聚合的运动过程的研究常被忽略。依据全球古地磁数据和古板块再造,可以获得板块运动轨迹,这些板块轨迹指示全球主要大陆在志留纪(约443Ma)-二叠纪(约250Ma)期间发生向北半球中纬地区的汇聚,具体表现为在泛大陆的形成过程中,全球板块运动具有顺时针旋转的特征,并且大板块(南美、波罗的、西伯利亚、澳大利亚等)纬向移动速率和板块自转速率明显高于小陆块的(华北、塔里木、扬子陆块等)。一些主要陆块显示不对称的"e"型顺时针旋转的漩涡轨迹,汇聚中心在中亚地区,以哈萨克斯坦马蹄形的最终形成和保留为标志。板块聚合的涡旋状运动轨迹,受控于上地幔流动过程产生长期的漩涡运动。这种对流运动在一定时间内(晚古生代)保持相对稳态的流动形式,导致泛大陆的形成。Since the formation of plate tectonic theory, the relativity between different plates are described deeply. However, movement process during the convergence of a series of plates are often overlooked. Based on global paleomagnetic data and paleo-plate reconstruction, paleolocation and motion trajectory can be obtained. The plate＇s motion trajectory indicates that major continents converged to the northern mid- latitudes during Silurian （about 443Ma）-Permian （about 250Ma）. It displays as： global plate motion have a characteristic of clockwise rotation during the formation of Pangea. And larger plates （South America, Baltica, Siberia, Australia, etc. ） significantly showed a higher latitudinal drifting rate and rotation rate than smaller blocks（North China, Tarim, Yangtze block, etc）. Trajectory of some major plates and continental blocks shows an asymmetric ＂e＂ type with a clockwise rotation. Central Asia is the convergent center with a symbol of Kazakhstan orocline. The scroll-shaped trajectory is controlled by long-term vortex motion in the upper mantle. This convective motion kept a relatively steady status in a certain period of time （late Paleozoic）, leading to the formation of Pangea.

关 键 词：古地磁 晚古生代 泛大陆 运动轨迹 涡旋运动 

分 类 号：P541[天文地球—构造地质学]