地质通报2018，Vol.37Issue(5)：881-894,14.
大兴安岭中段索伦地区满克头鄂博组火山岩年龄、地球化学特征及其构造环境
Chronology and geochemistry of volcanic rocks from Manketouebo Formation in the Suolun area, central Da Hinggan Mountains and their tectonic implications
摘要
Abstract
In this study,the authors conducted detailed geochronological,geochemical and Hf isotopic researches on the volcanic rocks of the Manketouebo Formation from the Suolun area in the central Da Hinggan Mountains.LA-ICP-MS zircon U-Pb dating reveals that the Manketouebo volcanic rocks from the Suolun area were formed in 140～138Ma,i.e.,the early Early Cretaceous rather than Late Jurassic as previously thought.Geochemical data show that the volcanic rocks are characterized by high silicon,rich alkali,weakly peraluminous nature (A/CNK=0.99～1.34) and high degree of differentiation,thus belonging to high-k calc-alkaline series.They are enriched in LILEs (Rb,Th,U,K) and LtREEs,and depleted in HFSEs (Nb,Ta,Ti,P).Their zircon Hfisotopic compositions show that the Manketouebo volcanic rocks of the study area have relatively high εHf(t) values (+4.06～+8.24) with the two-stage model ages ranging from 936Ma to 664Ma,implying that they were probably derived from partial melting of juvenile crustal materials that accreted from the depleted mantle.According to the regional geologic data,it is concluded that the volcanic rocks of the Manketouebo Formation formed in a post-orogenic extensional setting,which was probably closely related to the collapse of orogenic belt after the closure of Mongol-Okhotsk Ocean.关键词
大兴安岭中段/满克头鄂博组/锆石U-Pb年龄/Hf同位素/LA-ICP-MSKey words
central Da Hinggan Mountains/Manketouebo Formation/zircon U-Pb ages/Hfisotope/LA-ICP-MS分类
天文与地球科学引用本文复制引用
高龙飞,和钟铧,隋振民,陆凯杰,刘峰岩..大兴安岭中段索伦地区满克头鄂博组火山岩年龄、地球化学特征及其构造环境[J].地质通报,2018,37(5):881-894,14.基金项目
中国地质调查局项目《内蒙古1∶5万马家沟、阿林一合、平安屯幅区域地质矿产调查》(编号:12120114012901) （编号:12120114012901）
