Geochemistry of intrusive rock in Dachang tin-polymetallic ore field, Guangxi, China: Implications for petrogenesis and geodynamics  

广西大厂锡多金属矿田侵入岩地球化学特征:岩石成因及地球动力学意义(英文)

作　　者：成永生[1,2,3] 

机构地区：[1]中南大学有色金属成矿预测教育部重点实验室,长沙410083 [2]中南大学地球科学与信息物理学院,长沙410083 [3]中国科学院地球化学研究所矿床地球化学国家重点实验室,贵阳550002

出　　处：《Transactions of Nonferrous Metals Society of China》2015年第1期284-292,共9页中国有色金属学报（英文版）

基　　金：Project(41202051)supported by the National Natural Science Foundation of China;Project([2014]76)supported by the Platform of Scientific and Technological Innovation for Hunan Youth,China;Project(2014T70886)supported by the Special Program of the Postdoctoral Science Foundation of China;Project(2012M521721)supported by China Postdoctoral Science Foundation

摘　　要：The major element, trace element and rare earth element（REE） of the intrusion rock from the Dachang ore field in Guangxi, China, were analyzed. The results show that the phenocryst（about 15%） and matrix（about 85%） mainly consist of quartz, K-feldspar and plagioclase. The rock is composed of low content of Si and high content of Al2O3, low contents of Ca, Fe2O3, Na, TiO2, etc. The intrusion rock has the medium alkali content, attributing to K-rich type rock; and contains medium to low REE contents, of which light rare earth elements（LREEs） and heavy rare earth elements（HREEs） are highly fractionated, showing a weak negative Ce anomaly and a negative Eu anomaly. These rocks are enriched in LREE, and the large ion lithophytes elements（LILE） are rich in Rb, Sr, and U; the high-field-strength elements（Nb, Th, etc） are relatively depleted. The REE chondrite-normalized patterns are consistent with the overall, roughly indicating their similar characteristics, sources and evolution. The intrusion rock mainly formed during the collisional and within-plate periods.对广西大厂矿田的侵入岩体开展主量元素、微量元素以及稀土元素的分析。结果表明,岩石中斑晶和基质主要由石英、钾长石以及斜长石组成,其中,斑晶约占15%,基质约占85%。岩石中硅含量偏低,Al2O3含量偏高;另外,Ca、Fe2O3、Na以及TiO2等含量也较低。侵入岩体中碱含量中等,属于富钾型岩石;稀土元素含量中等至偏低,其中,轻稀土元素和重稀土元素高度分馏,显示出Ce微弱负异常、Eu负异常特征。岩体富集轻稀土元素,Rb、Sr以及U等大离子亲石元素也较富集,而Nb、Th等高场强元素则相对亏损。稀土元素球粒陨石标准化分布型式总体表现出较好的一致性,大体上表明各岩体具有相似的特点、来源以及演化等,侵入岩体主要形成于碰撞时期以及板内构造时期。

关 键 词：GEOCHEMISTRY PETROGENESIS tectonic setting magma evolution Dachang ore field GUANGXI 

分 类 号：P618.2[天文地球—矿床学]