塔里木板块坡十侵入体地化特征及岩石成因  

Geochemical characteristics and petrogenesis of Poshi intrusion in Tarim Block and its mineralization

作　　者：夏明哲[1,2] 王子玺[1] 王垚[1] 段星星[3] 夏昭德[1] 姜常义[1,2] 

机构地区：[1]长安大学地球科学与国土资源学院,陕西西安710054 [2]教育部西部矿产资源与地质工程教育部重点实验室,陕西西安710054 [3]中国地质调查局西安地质调查中心,陕西西安710054

出　　处：《西安科技大学学报》2013年第4期417-423,共7页Journal of Xi’an University of Science and Technology

基　　金：国家自然科学基金项目(41102045);中国地质调查局工作项目(1212011120498)

摘　　要：坡十侵入体位于塔里木板块东北部坡北岩体内,是该岩体第三阶段岩浆活动形成的小侵入体之一。主要岩石类型有纯橄岩、二辉橄榄岩、斜长二辉橄榄岩、橄榄二辉岩和斜长橄榄二辉岩。岩石化学组成属拉斑玄武岩系列,普遍富集大离子亲石元素,岩石εNd(t)=+1.3～+8.5,显示亏损型地幔特征。岩石学和地球化学特征表明原生岩浆为苦橄质岩浆,岩浆演化过程发生了一定程度的同化混染作用,坡十侵入体与塔里木板块东北部的二叠纪幔源岩浆岩应该是塔里木大火成岩省的组成部分。Poshi intrusion is located in Pobei rock body, in the northeast of Tarim Block. It is one of a small intrusions formed during the third stage of the magmatism of Pobei rock body. The main rock types are dunite, lherzolite, PI - bearing lherzolite, olivine websterite and P1 - bearing websterite. The main ele- ments belong to tholeitiitic series affine and enrich in LILES. The eNd（t） value of the rocks ranges from ＋ 1.3 to ＋ 8.5, which indicate that the magma was derived from depleted mantle. The geochemical fea- ture shows the primary magma is picritic and was subjected crust assimilation contamination. Therefore, Poshi intrusion is an affinity with mantle plume, the Early Permain mantle-derived magmatie rocks in Northeastern Tarim Plate are a part of Tarim Large Igneous Province.

关 键 词：岩石成因 地球化学 坡十侵入体 塔里木板块 

分 类 号：P596[天文地球—地球化学] P618.41[天文地球—地质学]