地质找矿论丛2017，Vol.32Issue(2)：245-253,9.DOI:10.6053/j.issn.1001-1412.2017.02.011
东昆仑那陵格勒河南上三叠统鄂拉山组火山岩地球化学特征及构造环境
Geochemistry and Tectonic Setting of Late Triassic Volcanics In Elashan formation in South of Nalingelehe river, East Kunlun
摘要
Abstract
Volcanics of Late Triassic Elashan formation (T3e) in south Nalinggele river,East Kunlun are mainly dacitic glassy,crystal fragmental tuff and dacitic ignimbrite with high alkaline,high potassium and high aluminum.ω(SiO2)=69.12～74.52％,ω(Na2O+K2O)=6.42％～7.33％,Rittmann coefficient δEu=0.54～0.67,aluminum saturation index ASI 1.02～1.17 belonging to paraluminal high-K calc-alkaline rock series.Analysis of ω(LREE)/ω(HREE)=11.02～15.99 and δEu=0.54～0.67 are of LREE enrichment and medium Eu depletion.Trace element analysis shows stronger enrichment of K,Rb,Ba and Th and evident depletion of Sr,Ti,Sc,Cr.The data mentioned above are characteristic of post collision crust remelting products.Sample from basaltic crystal fragmental tuff of Elashan formation dated at U-Pb age of 246.8 Ma±1.7 Ma thus the formation is formed in Late Triassic Epoch.According to com prehensive analysis volcanics of Elashan formation may be the product of the partially remelted thickening crust during the post lateral compression dominant continent-continent collision thus is a post Indosinian period rock formation in collisional volcanic basin.关键词
鄂拉山组/火山岩/地球化学/构造环境/锆石U-Pb/东昆仑地区Key words
Elashan formation/volcanics/geochemistry/tectonic setting/zircon U-Pb dating/East Kunlun分类
天文与地球科学引用本文复制引用
张得鑫,曾小平,魏小林,魏云祥,杨延乾,李嘉泰..东昆仑那陵格勒河南上三叠统鄂拉山组火山岩地球化学特征及构造环境[J].地质找矿论丛,2017,32(2):245-253,9.基金项目
中国地质调查局项目(编号:1212010818044)资助. （编号:1212010818044）
