地质通报Issue(11)：1759-1767,9.
藏北羌塘盆地望湖岭组流纹岩地球化学特征及其地质意义
Geochemical characteristics of Wanghuling Formation rhyolite in the Qiangtang Basin and their geological significance
摘要
Abstract
It is extensively known that the Guoganjianianshan late Triassic Wanghuling Formation is the most important sedimentologic evidence of the closure of the Lungmu Co-Shuanghu-Lancang River plate suture zone;nevertheless, so far the petrogenesis of the rhyolite remains unclear. The bulk rock geochemical analysis indicates the characteristics of high silica, rich alkali and Al, suggesting calc-alkali peraluminous rhyolite. The rhyolite samples are rich in LREE, the fractionation between LREE and HREE is strong with LREE/HREE being 6.39-7.72, and there exists obvious Eu negative anomaly. In addition, the rhyolite samples are enriched in Rb, Th, U, K, depleted in Ba, Ta, Nb, Sr, and prominently depleted in P and Ti, demonstrating the characteristics of post-collision volcanic rocks. An integrated analysis of geological survey information reveals that the Lungmu Co-Shuanghu-Lancang River plate suture zone was closed in late Triassic. The authors preliminarily hold that the rhyolite resulted probably from magmatic activity in the process of decompression after the lithosphere collision, and was formed in the stress relaxation phase of the post-collision environment.关键词
羌塘中部/果干加年山/流纹岩/地球化学/构造意义Key words
Central Qiangtang/Guoganjianianshan/rhyolite/geochemistry/geological significance分类
天文与地球科学引用本文复制引用
刘一鸣,李才,王明,吴彦旺,解超明,胡培远..藏北羌塘盆地望湖岭组流纹岩地球化学特征及其地质意义[J].地质通报,2014,(11):1759-1767,9.基金项目
国家自然科学基金项目（批准号41272240、41072166、41273047）和中国地质调查局项目 （）
