东秦岭丹凤群火山岩系及其包体地球化学研究  

GEOCHEMICAL RESEARCH ON VOLCANIC ROCKS AND ITS INCLUSIONS OF DANFENG GROUP IN EAST QINLING BELT

作　　者：匡少平 张本仁[1] 

机构地区：[1]中国地质大学

出　　处：《现代地质》1993年第4期444-457,共14页Geoscience

摘　　要：本文对东秦岭褶皱带中古生界丹凤群火山岩系及其包体进行了研究。从火山岩浆演化角度,指出丹凤群不是一套蛇绿混杂岩体,其主体火山岩为岛弧地幔在洋壳俯冲诱导下重熔形成A类岩浆演变所形成,并含有少量的洋壳物质在俯冲带中发生熔融形成B类岩浆的衍生产物。岛弧的地壳结构控制着两类岩浆的演化,它是造成丹凤群火山岩岩石系列、岩石组合、元素地球化学分布及分异在空间上差异的原因。Danfeng Group is composed of a sedimentary--volcanic rock series in Palaeozoic tecton- ic belt of East Qinling. The detall systematic geochemical research reveals that the host of Danfeng Group is result of differentiation of ' A Type' magma which was born in partial melting of mantle under island arc, while the minority developed from ' B Type' magma which came into the lower degree partial melting (4%) of oceanic crust in subduction zone. The crust structure of island arc intimately controlled the magmatic evolution.

关 键 词：火山岩 东秦岭 丹凤群 地球化学 

分 类 号：P588.14[天文地球—岩石学]