川东华蓥山褶皱带西天超大型玄武岩矿床地质特征及岩石成因  

GEOLOGY AND GENESIS OF XITIAN SUPER-LARGE BASALT DEPOSIT IN HUAYINGSHAN FOLD BELT,EASTERN SICHUAN

作　　者：黄从俊 李明辉[1] HUANG Cong-jun;LI Ming-hui(Chengdu Center of China Geological Survey,Chengdu 610081,China)

机构地区：[1]中国地质调查局成都地质调查中心,四川成都610218

出　　处：《地质与资源》2023年第3期301-310,300,共11页Geology and Resources

基　　金：中国地质调查局项目“成渝双城经济圈资源环境承载能力监测评价”(DD20221733);“四川广安资源环境综合地质调查”(DD20190521).

摘　　要：通过野外和镜下岩相学观察,结合主、微量元素地球化学方法,研究了四川省广安市邻水县西天超大型纤维用玄武岩矿床的地质特征,分析了矿石工业指标和矿床成因.结果表明:矿床位于川东褶皱带华蓥山背斜东翼,矿体呈似层状赋存于上二叠统峨眉山玄武岩组(P3β)地层中,矿石储量约1594×10^(4)t,达超大型规模;主量元素地球化学特征表明,西天玄武岩岩浆属高钛、高钾钙碱性-钙碱性系列;稀土元素、微量元素地球化学特征与区域内高钛峨眉山玄武岩及OIB型玄武岩特征相似;西天玄武岩为峨眉山大火成岩省的外带组成部分,形成于板内构造环境,岩浆演化来源于OIB型源区且基本未受地壳物质混染,为地幔热柱成因的产物;矿床中的柱状节理玄武岩、块状玄武和气孔状玄武岩可用于纤维拉丝生产.Through field survey and petrographic observation under microscope,combined with geochemical analysis for major and trace elements,the paper studies the geological characteristics of Xitian super-large fiber-used basalt deposit in Linshui County of Sichuan Province,and analyzes the industry indexes of ores and deposit genesis.The results show that the deposit is located in the east wing of Huayingshan anticline of eastern Sichuan fold belt,and the orebody is occurred in stratoid in the Upper Permian Emeishan basalt formation,with the ore reserves about 15.94 Mt,reaching the super-large size.The geochemistry of major elements indicate that the Xitian basaltic magma belongs to high Ti,high K calc alkaline-calc alkaline series.The geochemical characteristics of trace and rare earth elements are similar to those of the regional high Ti Emeishan basalt and OIB-type basalt.The Xitian basalt is the outer zone component of the Emeishan large igneous province,formed in the intraplate tectonic environment,with the magmatic evolution from OIB source area and basically no hybridization of crustal materials,which is of mantle plume origin.The columnar jointed,massive and vesicular basalts in the deposit can be used for fiber drawing production.

关 键 词：华蓥山褶皱带 玄武岩矿床 纤维材料 岩浆岩 四川省 

分 类 号：P619.2[天文地球—矿床学]