岩石矿物学杂志2018，Vol.37Issue(1)：19-33,15.
柴达木盆地西北缘石英闪长岩的形成时代、岩石成因及地质意义
The age, petrogenesis and geological significance of quartz diorite on the northwestern margin of Qaidam basin
摘要
Abstract
The quartz diorite on the northwestern margin of Qaidam basin is characterized by high Al2O3,low Alk and Na2O ＞ K2O,with alumina saturation index A/CNK being 0.87 ～ 0.91.These features suggest that this quartz diorite belongs to calc-alkaline peraluminous and metaluminous rocks.The chondrite-normalized REE show right-inclined patterns with slightly negative Eu anomaly,and the primitive mantle normalized trace element spidergrams are characterized by enriched LILE(such as Rb,Th and U),depleted HFSE(such as Nb,Ta,P and Ti),low Nb/La and Rb/Nb ratios,which are comparable with the characteristics of I-type granites.High CaO/Na2O(2.32～2.64)ratios and diagrams show that the pluton was derived from remelting of the metamorphic basalt in the lower crust.The initial temperature of magma was ＞768℃ by using whole rock Zr thermometer.Rock geochemical characteristics indicate that the pressure of the source region was probably ＞ 1.5 Ga,and the residual facies was correspondingly garnet + amphibole + rutil.Combined with the cathodoluminescence (CL) images and element features of zircon,this study yielded an age of 252 ± 1 Ma for pluton using LA-ICP-MS zircon U-Pb dating.On the basis of regional geological evolution,the authors hold that Zongwulong oceanic crust subducted toward Oulongbuluke block in Late Permian.关键词
柴达木盆地西北缘/石英闪长岩/锆石U-Pb测年/岩石成因/地质意义Key words
northwestern margin of Qaidam/quartz diorite/zircon U-Pb dating/petrogenesis/geological significance分类
天文与地球科学引用本文复制引用
辜平阳,陈锐明,查显锋,董增产,庄玉军,查方勇,李培庆..柴达木盆地西北缘石英闪长岩的形成时代、岩石成因及地质意义[J].岩石矿物学杂志,2018,37(1):19-33,15.基金项目
Natural Science Foundation of Shaanxi Province (2017JM4001) （2017JM4001）
Project of China Geological Survey(1212011121193,DD20160014) （1212011121193,DD20160014）
National Natural Science Foundation(41002063)陕西省自然科学基金项目(2017JM4001) （41002063）
中国地质调查局地质调查项目(1212011121193,DD20160014) （1212011121193,DD20160014）
国家自然科学基金项目(41002063) （41002063）
