摘要
民久玛淡色花岗岩大地构造属于喜马拉造山带中东部的喜马拉雅地块,呈不规则状侵位于侏罗系普普嘎组碳酸盐岩中,其主要岩性为(含电气石)白云母二长花岗岩。通过对白云母二长花岗岩进行LA-ICP-MS锆石U-Pb测年,年龄为:23±0.7Ma(MSWD=1.4),时代为中新世。属于新喜马拉雅阶段(Neo-Himalayan:26~13Ma),与藏南拆离系(STDS)活动时代相吻合。反映了STDS的活动促使了高喜马拉雅地区的快速隆起,产生淡色花岗岩,使喜马拉雅地区从挤压背景过渡到了伸展垮塌背景这一造山过程。为喜马拉雅淡色花岗岩的研究提供了新的年代证据。
The Minjiuma leucogranite intrusive body was emplaced irregularly in carbonate rock of the Jurassic Pupuga Formation in the Himalayan landmass of the east-central Himalayan orogenic belt.The leucogranite is a(tourmaline)muscovite monzogranite.Its LA-ICP-MS Zircon U-Pb age values are 23±0.7 Ma(MSWD=1.4),being emplaced in the Miocene.It coincides with the active age of the South Tibetan detachment system(STDS)in Neo-Himalayan(26~13 Ma).It indicates that the activities of STDS promoted the rapid uplift of the high Himalayan region which resulted in the emplacement of the leucogranite intrusive body and made the Himalayan orogenic process from compressive to extensional collapse.This paper provides new age evidence for the study of Himalayan leucogranite.
作者
罗巍
肖渊甫
魏永峰
杨剑红
林美英
LUO Wei;XIAO Yuan-fu;WEI Yong-feng;YANG Jian-hong;LIN Mei-ying(College of Earth Sciences,Chengdu University of Technology,Chengdu 610059;Regional Geological Surveying Team,BGEEMRSP,Chengdu 610213)
出处
《四川地质学报》
2020年第1期3-6,10,共5页
Acta Geologica Sichuan
基金
西藏哈热地区H46E023006,H46E023007,H46E024006,H46E024007四幅地质矿产综合调查(12120115022901)项目资助,所属计划项目为:冈底斯-喜马拉雅铜矿资源基地调查项目。
