青海1∶25万曲麻莱县幅地质调查成果与主要进展  

New Results and Major Progress in Regional Geological Survey of the 1∶250000 Qumarlêb Xian Sheet in Qinghai

作　　者：段其发[1] 牛志军[1] 白云山[1] 赵小明[1] 汤朝阳[1] 涂兵[1] 魏运许[1] 曾波夫[1] 

机构地区：[1]宜昌地质矿产研究所,湖北宜昌443003

出　　处：《华南地质与矿产》2006年第3期77-81,共5页Geology and Mineral Resources of South China

基　　金：中国地质调查局"1:25万曲麻莱县幅区域地质调查"项目(200313000006)

摘　　要：在青海南部曲麻莱地区二叠纪一古近纪地层中发现动、植物化石和孢粉化石多属多种，系统建立了测区的岩石地层和生物地层序列；在巴颜喀拉山群中发现遗迹化石33属54种，为深海Nereites遗迹相的典型代表，反映出复理石相深水沉积特征；晚三叠世沉积盆地分属周缘前陆盆地、弧前盆地和弧后前陆盆地；第四纪地层中获得了6个年龄数据（7．02～225．81kaBP），侵入岩中获得4个同位素年龄数据（169～130Ma）；系统的对岩石学、岩石地球化学和同位素地球化学进行了研究，表明区内岩浆岩总体显示出弧岩浆岩的特点。区内变质作用以区域变质作用为主，主体属低绿片岩相；并重新厘定了通天河蛇绿混杂岩的物质组成和结构。Various genera and species of fossil animals and plants have been found in Permian to Paleogene strata in the mapping area, southern Qinghai. Lithostratigraphic sequences and biostratigraphic sequences have been systematically established; 33 genera and 54 species of trace fossil have been discovered in the Bayan Har Shan Group, and they are typical representatives of the abyssal Nereites ichnofacies, reflecting the features of the flysch facies deep-water sedimentary environment. In the Late Triassic, the sedimentary basins are divided into peripheral foreland basin, forearc basin and retro-arc foreland basin. Six age data （7.02 - 225.81kaBP） in Quaternary strata and four isotopic age data （ 169 - 130 Ma）of intrusive rocks have been obtained, and the study of a number of lithogeochemical data is indicated that magma rocks in the mapping area characterize arc magma rock. The metamorphism, which is main regional metamorphism, formed an amount of low-grade green-schist facies regional metamorphic rocks. The material component and the structure mode of the Tongtian He ophiolitic mélange are again defined by detailedly geological survey.

关 键 词：地层序列 沉积盆地 弧岩浆岩 区域变质岩 蛇绿混杂岩 青海 

分 类 号：P623.12[天文地球—地质矿产勘探]