对冈底斯-拉萨变质区内变质岩及变形变质特征进行研究, 有助于区域构造格架的建立以及探讨该区演化历史, 为青藏高原地区的地质构造演化研究提供新的基础资料。西藏拉萨北部一带变质岩研究较少, 本次从岩相学方面对其做了总结与研究, 并对变形变质作用期次进行简要探讨。该区划分为两个变质带, 从南向北依次划分为叶巴沟-甘丹寺变质带、设兴-边交林变质带。变质岩类型为板岩、千枚岩和片岩。动力变质作用表现形式为脆性变形变质、韧性变形变质, 区内发育数千米的动力变质岩带, 基本都属于低绿片岩相带。该区变质作用是在新特提斯洋壳板块向北俯冲、消减、碰撞的地质背景下发生的。且随着构造环境的变迁和热流的变化, 在不同地质发展阶段产生不同的变质作用。

The study of metamorphic rocks and deformation and metamorphic features in Gangdise-Lhasa metamorphic zone is helpful for the establishment of regional tectonic framework and the discussion of the evolution history of the region, which will provide new basic data for the study of geological structure evolution in the Qinghai-Tibet Plateau. There are few studies on metamorphic rocks in the northern area of Lhasa, Tibet. This paper summarizes and studies them from the perspective of petrography, and briefly discusses the stages of deformation and metamorphism. The area is divided into two metamorphic belts, which are divided into Yebagou-Gandansi metamorphic belt and Shexing-Binjiaolin metamorphic belt from south to north. The types of metamorphic rocks are slate, kyanite and schist. The dynamic metamorphism is manifested as brittle deformation and ductile deformation. The dynamic metamorphic rock belt developed in the area is several kilometers long, which basically belongs to the low green schist facies belt. The metamorphism in the area occurs under the geological background of the northward subduction, subduction and collision of the Neotethys oceanic crust plate. And with the change of tectonic environment and heat flow, different metamorphisms are produced in different geological development stages.