摘要
确定印度大陆和欧亚大陆的碰撞时代是青藏高原地质研究中非常重要的构造问题,目前要准确界定两大陆的碰撞时代还存在不少困难。从碰撞定义出发,将发生于印度大陆与欧亚大陆之间的弧—陆、陆—陆碰撞行为划分为初始碰撞、主碰撞和后碰撞3个阶段,每一阶段都具有一个作用过程,可以持续很长一段时间。在综合分析最近古地磁、地层学、古生物学以及岩石学资料后,对两大陆的初始碰撞时限进行了讨论,指出印度和欧亚大陆之间的初始碰撞可能开始于白垩纪晚期,大约在70～65MaBP;然后主要从与碰撞事件有关的岩石学和构造变形响应事件出发,初步分析了两大陆的主碰撞和后碰撞时限,提出主碰撞期出现在55～50MaBP前后,印度大陆和欧亚大陆之间的陆—陆碰撞行为结束于45～35MaBP,随后两大陆转为强烈的陆内汇聚时期。
One of the major tectonic questions in the study of Tibetan Plateau geology is what was the precise age of collision between India and Eurasia. Obviously, the arc-continental, continent-continental collision between the India and Asian continents is a process that is rather difficult to define. Many controversies have focused on the age of initial collision between these two continents in recent years. As for the definition of collision, the collision process of arc-continent, continent-continent between India and Eurasia has been divided into three stages, which consist of initial collision, the climax of collision and post-collision, every stage could continues for a long period. Based on the synthetic analysis of paleo-geomagnetism, stratigraphy, and paleontology, this paper firstly discusses the age of initial collision between the India and Asian continents and points out that the age of initial collision between India and Asia might start in the late part of Late Cretaceous (about 70～65 Ma). The ages of climax of collision and post-collision have been preliminary discussed in this paper according to the response events of petrology and structural deformation in the process of collision between India and Eurasia. The authors suggest that the ages of climax of collision and post-collision between India and Eurasia maybe occur at about 55～50 Ma and 45～35 Ma respectively, and subsequently shift to intra-continental convergent stage.
出处
《地球科学进展》
CAS
CSCD
2004年第4期564-571,共8页
Advances in Earth Science
基金
国家重点基础研究发展规划项目"印度与亚洲大陆主碰撞成矿带作用"(编号:2002CB412600)子课题"成矿潜力评估与战略新区预测"(编号:2002CB412600)
中国地质大学"岩石圈构造
深部过程及探测技术"教育部重点实验室开放课题(编号:2003004)
中国地质调查局青藏高原地质研究综合项目"青藏高原地质构造及资源环境效应研究"(编号:200113900069)
"青藏高原南部空白区基础地质调查与研究"(编号:1212010310102)资助
关键词
初始碰撞
主碰撞
后碰撞
碰撞时限
印度-欧亚大陆
Initial collision
Climax of collision
Post-collision
Age of collision
India-Asia.
