西藏措勤区一带蛇绿岩特征及其构造环境探讨

An Approach to Geological Features and Tectonic Setting of Ophiolite Suite in Coqên,Tibet

文章中所述范围囊括于西藏1∶25万措勤区幅内,处于雅鲁藏布江基性-超基性岩带—念青唐古拉岛弧岩浆带内。岩浆活动频繁,从侏罗纪到第四纪均有不同程度的岩浆活动。岩浆侵入活动主要发生在燕山期和喜马拉雅期,以中酸性岩占绝对优势,基性-超基性岩次之。区内基性-超基性岩属昂仁蛇绿岩的组成部分(以下称安巴蛇绿岩),此套岩类主要形成于洋脊,并具有向洋岛过渡的构造环境。其形成时代为晚白垩世早期。

The Coqen region lies in the Yarlung Zangbo basic-ultrabasic rock belt-Nyainq6ntanglha island arc magmatic belt characterized by strong magmatic activity during Jurassic-Quaternary. Intrusions dominated by intermediated and acid intrusions over basic-ultrabasic intrusions were emplaced during Yenshanian and Himalayan epochs. The basic-ultrabasic intrusions as parts of the Ngamring ophiolite suite or Anba ophiolite suite were emplaced in an ocean ridge setting transitional to oceanic islands during the early Late Cretaceous.