云南祥云马厂箐富碱斑岩体的地球化学特征  

Geochemistry of the Machangqing Alkaline-rich Porphyry in Xiangyun,Yunnan Province

作　　者：王治华[1] 郭晓东[1] 葛良胜[1] 王科强[1] 邹依林[1] 张勇[1] 喻万强[1] 

机构地区：[1]武警黄金地质研究所,廊坊065000

出　　处：《地质与勘探》2009年第4期343-351,共9页Geology and Exploration

基　　金："十一五"国家攻关项目(编号:2006BAB01B10);武警黄金指挥部专项基金资助项目(编号:HJ07-02)联合资助

摘　　要：云南祥云马厂箐岩体是马厂箐铜钼矿的主要赋矿围岩,处于扬子板块西缘与北西向的金沙江—哀牢山深大断裂带东侧交汇部位,属于哀牢山—金沙江富碱侵入岩带的组成部分。马厂箐岩体主要为花岗斑岩、二长斑岩和正长斑岩。岩石富集大离子亲石元素(Rb、Sr、Ba、Th和U)和轻稀土元素(LREE)、相对亏损高场强元素(Ta、Nb和Ti),且Ta、Nb和Ti具"TNT"负异常;LREE/HREE值为8.04～23.99,δEu值为0.72～0.88,负Eu异常不明显。岩石的La/Yb和(La/Yb)N比值高,LR/HR、La/Sm和Ce/Yb变化较大。岩体的岩浆起源于壳—幔物质混合的一种所谓EMⅡ型富集地幔源;其壳幔混合特征,主要是俯冲进入上地幔的地壳物质与地幔物质发生了源区混合作用的结果;形成于碰撞后的板内构造环境。Located at the joint of western margin of the Yangtz plate and eastern side of NW-trending Ailaoshan-Jinshajiang major fault, the Machan- gqing intrusive body, being part of the alkaline-rich intrusion belt of Ailaoshan-Jinshajiang, is main host rock of the Machangqing copper-molybdenum deposit The Machangqing intrusive complex mainly consists of granite porphyry, monzonite porphyry and syenite-porphyry. The rocks are rich in large ion lithophile elements such as Rb,Sr,Ba,Th and U and light rare earth elements, depleted in Ta,Nb and Ti, with ＂TNT＂ negative anomaly. The values of LREE/HREE range between 8.04 and 23.99,8Eu from 0.72 to 0.88, without obvious negative Eu anormaly; The magma of the rockbody derives from the mixture of crust-mantle, as being called EM Ⅱ -type. The intrusive shows the characteristics of crust-mantle mixture, resulting from mixing in the mantle source with the crust material within the subduction zone and formed in a post-collisional intra-plate.

关 键 词：富碱侵入岩 地球化学特征构造环境原始地幔云南祥云马厂箐 

分 类 号：P632[天文地球—地质矿产勘探]