赣南余田群双峰式火山岩地球化学特征及构造环境  

Bimodal volcanic geochemistry characteristics and structural setting of Yutian Group,south Jiangxi

作　　者：刘帅[1] 黄美化[1] 巫建华[1] 管太阳[1] 

机构地区：[1]东华理工学院地球科学系,江西抚州344000

出　　处：《桂林工学院学报》2006年第3期320-327,共8页Journal of Guilin University of Technology

基　　金：核工业总公司重点攻关项目(Y1218960401)

摘　　要：余田群菖蒲组火山岩属典型的双峰式火山岩，基性火山岩稀土总含量较低，变化范围为（62．1-310．81）×10^-6；酸性火岩稀土总含量较高，变化范围为（142．31-643．39）×10^-6．从基性火山岩到酸性火山岩，随着SiO2的增加，分异程度愈强．对火山岩的微量元素组成特征研究表明：基性火山岩形成于板内环境，明显具富集地幔物质性质，且受地壳物质或花岗质岩石的混染；酸性火山岩岩浆主要来自浅部，具壳源性质．Volcanics of Changpu Formation, Yutian Group, is typical bimodal volcanic rock. There is less ∑REE in the basic volcanic rock. The range of ∑REE change is from 62. 1×10^-6to 310. 81 ×10^-6. The total content of REE in the acid volcanic is high, ranging from 142. 31 ×10^-6 to 643.39 ×10^-6. From the basic volcanic rock to the acid volcanic rock, with the SiO2 increase, the differential degree becomes obvious. The trace elementary composition research of volcanics shows： the basic volcanics forming in plate indicates the characteristics of mantle material and is mixed with the crust substance or granitic rocks. The magma of acid volcanic rock mainly comes from superficial part and has the characteristics of crust source.

关 键 词：火山岩 双峰式 分异程度 混染 赣南 

分 类 号：P588.14[天文地球—岩石学]