新疆阿尔泰山南缘卡拉先格尔斑岩铜矿带成因再认识——来自哈腊苏铜矿硫-铅-氢-氧同位素和^(40)Ar-_^(39)Ar年龄的约束  

New understanding on origin of Kalaxiangeer copper deposit on southern margin of Altay mountain, Xinjiang: Constraints from S-Pb-H-O isotope geochemistry and ^(40)Ar-^(39)Ar age of Halasu copper deposit

作　　者：闫升好[1] 滕荣丽 张招崇[3] 陈柏林[4] 陈文[5] 周刚 何立新 

机构地区：[1]中国地质科学院矿产资源研究所,北京100037 [2]山东地质矿产局第六地质勘查院,山东招远265400 [3]中国地质科学院地质研究所,北京100037 [4]中国地质科学院地质力学研究所,北京100081 [5]国土资源部同位素地质重点实验室,北京100037 [6]新疆地质矿产局第四地质队,新疆阿尔泰836500

出　　处：《矿床地质》2006年第3期292-301,共10页Mineral Deposits

基　　金：国家科技攻关305项目(2001BA609A_07_02);国家重点基础研究973项目(2001CB409807);"我国固体矿产资源第二轮区划深化总结"项目(200110000004)的联合资助

摘　　要：通过对卡拉先格尔铜矿带中的哈腊苏斑岩铜矿床详细的野外地质调查和系统的同位素地球化学示踪和测年研究,探讨了阿尔泰南缘铜矿的成矿时代及矿床成因。研究表明,卡拉先格尔铜矿带的铜矿化主要呈不均匀团块、细脉或细脉浸染状产于受断裂控制的钾长石_石英脉、绿帘石脉以及石英_方解石脉中,线型分布明显,空间分布极不均匀,缺乏典型斑岩铜矿的面型蚀变矿化分带。含矿钾长石脉40Ar_39Ar年龄为(230±5)Ma,大大晚于容矿斑岩脉的形成时代〔锆石SHRIMPU_Pb年龄(380.8±5.7)Ma〕。硫_铅同位素指示成矿物质主要源于火山岩地层和花岗闪长斑岩脉。氢_氧同位素显示成矿流体为岩浆水和大气降水的混合物。据此认为,卡拉先格尔铜矿带主成矿时代为印支期,成矿作用与后造山阶段沿NNW向老山口断裂发育的偏碱性岩浆活动有关,但不排除存在同造山期的斑岩型矿化。Based on detailed field geological survey and systematic isotope geochemical studies, the authors have discussed the metallogenic epoch and origin of the Kalaxiangeer copper deposit on the southern margin of the Altay Mountain, Xinjiang. The copper-bearing minerals mainly occur in the form of heterogeneous gobbets and veinlets disseminated in various veins such as K-feldspar-quartz veins, epidote veins and quartz-calcite veins, which are obviously controlled by NNW-striking faults. The mineralization distribution in the ore district is highly uneven and shows lack of pervasive alteration-mineralization zonation typical of representative porphyry copper deposits. The （230 ± 5） Ma age for the formation of copper-bearing K-feldspar was obtained by ^40Ar-^39Ar method, which is remarkably younger than the age of the ore-hosted porphyry[（380.8 ± 5.7） Ma, zircon SHRIMP U-Pb age]. The sulfur and lead isotope compositions indicate that the ore-forming materials were mainly derived from the volcanic rocks and granodioritic porphyries. The hydrogen and oxygen compositions suggest that the ore fluid is a mixture of magmatic water and meteoric water. According to the above results, the authors have reached the conclusions that the main metallogenic epoch in the Kalaxiangeer copper deposit is Indosinian, and that most of the mineralization might have been related to the post-orogenic meta-alkaline granitic magnmtism developed along the NNW-striking Laoshankou fault. Nevertheless, it is also probable that there might have existed nonsignificant syn-orogenic porphyry-style mineralization.

关 键 词：地球化学 ^40AR-^39AR年龄 斑岩铜矿 哈腊苏铜矿 卡拉先格尔铜矿带 阿尔泰 

分 类 号：P618.41[天文地球—矿床学]