地质与勘探2012，Vol.48Issue(4)：768-774,7.
略谈藏东吉塘群
A Brief Discussion of the Jitang Group in Eastern Tibet
摘要
Abstract
The Jitang rock group is widely distributed in eastern Tibet.Previous researches divided it into two members,i.e.,the upper Youxi Formation,composed of albite-quartz-schist,albite-twomica-schist and albite-actinolite-schist,and the lower Enda Formation,mainly composed of biotite-twomica-gneiss,granitic gneiss and quartz-schist,both of which belong to the pre-Sinian period.In recent years,geological mapping at a scale of 1：250000 divided the Enda Formation into two members,i.e.the migmatite member and hypometamorphic member composed of schist,gneiss,granulite,amphibolite and marble.Geological mapping obtained the isotopic age as 240±12Ma（Zircon U-Pb） and 226.1±2.4（Ar-Ar）for the Youxi Formation,belonging to Paleozoic.Thus,the Youxi Formation is renamed as Youxi rock group.Migmatite from the Enda Formation obtained zircon SHRIMP U-Pb isotopic ages as 254±8Ma,232±9Ma and 227±1.8Ma.The previous 1：200000 regional survey has measured the zircon U-Pb age as 253±9Ma and 195Ma.This may suggest that this rock member may be the Variscan to Yanshanian metamorphosed granitic intrusions,and should be removed from the Jitang group.The original Enda Formation is the real pre-Sinian Jitang group,composed of gneiss,mica schist,quartz schist,gneiss-based folder granulite,amphibolite rocks and marble,and is attributed to the Mesoproterozoic period.关键词
吉塘岩群/古中元古代/酉西岩群/古生代/变质花岗岩/华力西至燕山期/西藏东部Key words
Jitang Group/Mesoproterozoic/Youxi Group/paleozoic/metamorphic granite/from Variscan to Indosinian/eastern tibet分类
天文与地球科学引用本文复制引用
沙绍礼,谢尧武,彭道平,陈应明,刘学龙,张娜..略谈藏东吉塘群[J].地质与勘探,2012,48(4):768-774,7.基金项目
中国地质调查局地质大调查项目 （）
