西藏多龙矿集区色那铜金矿地质特征、侵入岩地球化学特征及其地质意义  

Geological and Geochemical Characteristics and Significance of the Sena Cu-Au Deposit from Duolong Ore-concentration Area, Tibet, China

作　　者：高轲[1] 唐菊兴[2] 方向[2] 张志[3] 王勤[1] 杨欢欢[2] 王艺云[1] 冯军 

机构地区：[1]成都理工大学地球科学学院,四川成都610059 [2]中国地质科学院矿产资源研究所,北京100037 [3]中国地质调查局成都地质矿产研究所,四川成都610082 [4]西藏金龙矿业股份有限公司,西藏拉萨850000

出　　处：《矿物学报》2016年第2期199-207,共9页Acta Mineralogica Sinica

基　　金：国土资源部公益性行业科研专项项目(编号:201511017)

摘　　要：色那铜金矿是多龙矿集区内新近发现的又一个具有巨大找矿潜力的斑岩型矿床。在详细野外地质调查的基础上对区内与成矿具有密切关系的石英闪长玢岩体进行了岩石地球化学特征研究。结果表明区内斑岩为准铝质—过铝质岩类,高钾钙碱性—钙碱性系列,属于I型花岗岩类。稀土元素配分曲线显示为以富集轻稀土为特征的右倾型,且轻稀土分馏明显,而重稀土分馏不显著;δEu=0.89～1.05,显示无明显Eu异常,表明斜长石的结晶分异作用不明显;δCe介于0.84～1.51之间,平均值为1.08,无明显Ce异常。微量元素总体富集大离子亲石元素Rb、K、La、Sr、Sm,相对亏损高场强元素Nb、Ta、Zr、Hf、Ti等,显示出岛弧岩浆特征,微量元素构造环境判别显示其形成于岛弧环境。结合区域构造背景演化,表明色那铜金矿床可能形成于班公湖-怒江特提斯洋北向俯冲阶段。Sena Cu-Au deposit is a newly found porphyritic deposit with great prospecting potential in the Duolong ore-concentration area. Based on a detailed geological survey in the field of the area, this paper studies geochemical characteristics of quartz diorite porphyrite, which has a close relationship with the mineralization in the area. Results show that the regional porphyry is a high calc-alkali metaluminousperaluminous rock, belonging to I-type granite. Enrichment of REE distribution curve display characteristics of a LREE type, and the LREE fractionation is apparent, with no significant HREE fractionation; δEu = 0.89-1.05 and showing no obvious Eu anomaly, indicating that plagioclase crystallization differentiation is not obvious. The δCe is between 0.84-1.51, with a mean of 1.08 and no Ce anomaly. The LILE elements, including Rb, K, La, Sr and Sm are significantly enriched, while those inactive HFSE elements including Nb, Ta, Zr, Hf and Ti are depleted, showing the characteristics of island-arc magma, and trace element discrimination shows that it formed in island-arc environment. Combined with regional tectonic evolution, it is apparent that the Sena Cu-Au deposit may have formed in the northward subduction stage of the Bangonghu-Nujiang Tethys Ocean.

关 键 词：地球化学 石英闪长玢岩 色那铜金矿 西藏 

分 类 号：P618.41[天文地球—矿床学]