西藏古堆地区岩浆岩基本特征及对成矿的响应

Fundamental characteristics and metallogenic response of the magmatic rocks in Gudui area,Tibet

古堆地区地处喜马拉雅特提斯造山带中东部,介于藏南拆离系和雅鲁藏布缝合带2大构造单元之间,其显著特点是广泛发育中生代—新生代岩浆岩。在收集新近完成的1∶5万区域地质调查资料和相关研究成果的基础上,简要介绍了古堆地区地层及大地构造背景,详细论述了不同时期岩浆岩的地质和岩石矿物学特征,对岩浆岩的形成时代及特征进行讨论和对比分析研究,基本查明了岩浆岩的主体岩石类型、期次划分及其与成矿的关系,初步建立了成矿模式。本研究对于指导古堆地区找矿工作部署具有重要理论和现实意义。

The Gudui area is located in the middle east of the Tethys-Himalayan orogenic belt,between the 2 great tectonic units,namely Southern Tibet Detachment System and Yarlung Zangbo Suture Zone,and one of its notable characteristics is the widely developed Mesozoic-Cenozoic magmatic rocks.On the basis of collecting data from regional geological survey(1∶50000)recently completed and related research achievements,this paper briefly introduces the stratigraphic and geotectonic background of Gudui area,and in detail describes geological features,petrological and mineralogical characteristics of magmatic rocks during different periods.Discussion and comparative analysis of the formation ages and characteristics of magmatic rocks basically find out the main rock types,phase division of the magmatic rocks and their relation with metallogenesis,and preliminarily established the metallogenic patterns.The study bears theoretical and practical significance in guiding the deployment of prospecting work in Gudui area.