安徽沿江地区橄榄安粗岩系的特点和成因——大陆橄榄安粗岩系一例  

THE CHARACTERISTICS AND ORIGIN OF THE SHOSHONITES AROUND THE YANGTZE RIVER REACHES OF ANHUI ——AN EXAMPLE FROM CONTINENTAL SHOSHONITIC ROCKSERIES

作　　者：邢凤鸣 徐祥[1] 

机构地区：[1]安徽省地质科学研究所

出　　处：《安徽地质》1998年第2期8-9,11-12+14-16+18-2,共10页Geology of Anhui

基　　金：安徽省地矿局"八五"科技攻关课题

摘　　要：安徽沿江地区出露中生代橄榄安粗岩系火山岩，与岛弧或活动大陆边缘的橄榄安粗岩系不同，是一个新的类型。其特点是：以中性岩为主并与碱性岩共生；含少量或不含橄榄石；相对贫ＭｇＯ、ＣａＯ、Ｃｒ、Ｎｉ，而碱度（σ）较高。它是大陆地幔低度部分熔融产生的碱性玄武岩浆，通过深部ＡＦＣ混合，尤其是浅部结晶分异机制形成的。The Mesozoic shoshonitic volcanic rocks which outcropped around the Yangtze River reaches ,Anhui,are of a new type in contrast to others in arc and active continental margin.They are characterized by:the predominant intermediate rocks in paragenesis with alkaline rocks;having no or a little olivine;relatively poor MgO,CaO,Cr and Ni but higher alkalinity(σ).They are formed from alkali basaltic magma that slightly melted out of continental mantle by AFC mixing in depth,especially by the fractional crystallization in shallow horizon.

关 键 词：橄榄安粗岩系 特点和成因 安徽沿江 

分 类 号：P588.143[天文地球—岩石学]