摘要
以新一轮1∶25万区域地质调查及专题研究成果为基础,结合前期1∶20万区域地质填图和科学考察资料,对雅鲁藏布江结合带的区域地质背景、基本地质特征、构造演化模式及有关问题进行了探讨。以雅鲁藏布江结合带为重点,论述了三叠纪玉门蛇绿岩构造冲断片、晚三叠世郎杰学弧前增生楔、泽当-罗布莎-朗县蛇绿混杂构造冲断片和白垩纪朗县弧前构造混杂岩片的基本地质特征。并将雅鲁藏布江结合带中蛇绿混杂构造冲断片的原始层序与特罗多斯典型蛇绿岩剖面对比,初步建立了研究区各构造带从新元古代—寒武纪克拉通化阶段、奥陶纪—二叠纪克拉通陆表海发展阶段、三叠纪—侏罗纪洋盆主扩张阶段、侏罗纪—白垩纪俯冲消减阶段、白垩纪—渐新世闭合-碰撞造山阶段到中新世以来的伸展、拆离、快速隆升阶段之演化模式。
On the basis of the new-round 1：250000 regional geological survey and special-subject research, combined with the previous 1：200000 regional geological mapping and scientific expedition information, the paper discusses the regional geological setting, basic geological characteristics and tectonic evolution model of the Yarlung Zangbo junction zone and relevant problerns. With emphasis on the Yarlung Zangbo junction zone, the paper deals with the basic geological characteristics of the Triassic Yumen ophiolite thrust slice, Upper Triassic Langjiexue forearc accretionary wedge, Zeang-Luobusha-Langxian ophiolitic mélange thmst slice and Cretaceous Langxian forearc tectonic mélange sheet. The authors have also correlated the original sequence of ophiolitic mélange thrust slice in the Yarlung Zangbo junction belt with the typical ophiolite section in Troodos, Cypms and preliminarily constructed a model of evolution of various tectonic belts in the study area from the Neoprotero zoic-Cambrian cratonization stage→stage of Ordovician-Permian cratonic epicontinental sea development→stage of Triassic-Jurassic. main ocean basin spreading→Jurassic-Cretaceous subduction stage→stage of Cretaceous-Oligocene closing and collisional orogeny→stage of extension, detachment and rapid uplift since the Miocene.
出处
《地质通报》
CAS
CSCD
北大核心
2006年第6期700-707,共8页
Geological Bulletin of China
基金
中国地质调查局《1：25万林芝县幅、扎日区幅、隆子县幅区域地质调查及专题研究》项目（基2002002-18）成果之一.
