贵州省施秉大坪钾镁煌斑岩地球化学特征及源区指示  

Geochemical Characteristics and Source Area Indication of Potassium Magnesium Lamproite in Daping,Shibing of Guizhou Province

作　　者：杨毓红 黄艺 刘燊[3] 张锡贵[4] 杨朝贵 叶春 龚兴祥 文德修 熊碧 YANG Yu-hong;HUANG Yi;LIU Shen;ZHANG Xi-gui;YANG Ghao-gui;YE Chun;GONG Xing-xiang;WEN De-xiu;XIONG Bi(Guizhou Land and Mineral Resource Reservoir,Guiyang 550018,Guizhou,China;Engineering Technology Innovation Center of Mineral Resources Explorations in Bedrock Zones,Ministry of Natural Resources,Guiyang 550081,Guizhou,China;State Key Laboratory of Continental Dynamics,Department of Geology.Northwest University.Northern Taibai Street 229,Xi’an.710069,Shanxi,China;101Geological Part,Guzhou Bureau of Geology and Mineral Exploration and Development,Kaili 556000,Guizhou,China;Guizhou Nonferrous Metals Institute of Geological Exploration,Guiyang 550005,Guizhou,China)

机构地区：[1]贵州省土地矿产资源储备局 [2]自然资源部基岩区矿产资源勘查工程技术创新中心 [3]西北大学地质学系/大陆动力学国家重点实验室 [4]贵州省地质矿产勘查开发局101地质大队 [5]贵州有色和核工业地质局地质勘查院

出　　处：《贵州地质》2021年第1期51-58,共8页Guizhou Geology

基　　金：贵州省科学技术基金《黔东南钾镁煌斑岩岩墙群地球化学特征及其指示意义》合同编号:黔科合J字[2014]2109号。

摘　　要：借助矿物学和主微量元素研究手段,本论文对贵州省施秉县大坪钾镁煌斑岩开展了系统地球化学探讨。主元素研究显示,研究区钾镁煌斑岩SiO 2含量变化较低(35.055.0 wt.%),为超基性岩浆岩;Al 2O 3、TiO 2、CaO、P 2O 5和Na 2O指数表明研究区火成岩属典型的钾镁煌斑岩。另外,研究区钾镁煌斑岩显示出轻稀土元素(9371132 ppm)和高场强元素(Nb、Ta、Th和U)富集及重稀土元素(60.172.8 ppm)和大离子亲石元素(Rb、K、Sr和Ti)明显亏损的地球化学特征。系统研究显示,研究区钾镁煌斑岩源区为受到深俯冲物交代作用影响的石榴子石二辉橄榄岩地幔,钾镁煌斑岩为原始岩浆(深度>100 km)分离结晶的产物,岩浆在成岩过程并未受到明显地壳混染作用的影响。Based on mineralogy and major and trace element research,the systematic geochemistry of Wengsaodaping Potassium Magnesium Lamproite in Shibing,Southeastern Guizhou Province has been carried out.The main element study shows that the content of SiO 2 in the Potassium Magnesium Lamproite in the study area is relatively low(35.055.0 wt.%),the Potassium Magnesium Lamproite thus belong to ultra-basic magmatic rock.The indexes of Al 2O 3,TiO 2,Cao,P 2O 5 and Na 2O indicate that the igneous rocks in the study area are typical Potassium Magnesium Lamproite.In addition,the Potassium Magnesium Lamproite studied are characterized by enrichment of light rare earth elements(9371132 ppm)and high field strength elements(Nb,Ta,Th and U),and obvious depletion of heavy rare earth elements(60.172.8 ppm)and large ion lithophile elements(Rb,K,Sr and Ti).The systematic study shows that the source of Potassium Magnesium Lamproite studied is the transitional mantle(garnet lherzolite mantle)affected by deep subduction metasomatism,and the Potassium Magnesium Lamproite is the product of fractional crystallization of primitive magma(depth>100 km),but the magmatic process is not affected by obvious crustal contamination.

关 键 词：钾镁煌斑岩 主元素 微量元素 地球化学 源区特征 

分 类 号：P588.12[天文地球—岩石学] P59[天文地球—地质学]