天山—阿尔泰东部地区海西晚期后碰撞铜镍硫化物矿床:主要特点及可能与地幔柱的关系  

Late Variscan Post-collisional Cu—Ni Sulfide Deposits in East Tianshan and Altay in China:Principal Characteristics and Possible Relationship with Mantle Plume

作　　者：毛景文[1] Franco PIRAJNO 张作衡[1] 柴凤梅[3] 杨建民[1] 吴华[4] 陈世平[5] 程松林[4] 张长青[1] 

机构地区：[1]中国地质科学院矿产资源研究所,北京100037 [2]西澳大利亚地质调查局 [3]中国地质大学地球科学与资源学院,北京100083 [4]新疆地质矿产勘查开发局第六地质队,哈密839000 [5]新疆哈密市国土资源局,839000

出　　处：《地质学报》2006年第7期925-942,共18页Acta Geologica Sinica

基　　金：国家自然科学基金资助项目(编号40402012);国土资源大调查项目(编号1212010561506)的成果

摘　　要：天山-阿尔泰东部地区是中国重要的铜镍成矿区，近年来针对区内的铜镍矿床和相关岩体的研究不断取得进展，找矿也取得了一系列新突破，已经探明了十几个矿床和矿点。笔者基于以往研究成果，结合目前地质勘查和找矿评价的新进展，比较详细地全面总结了后碰撞铜镍硫化物矿床的基本特点、成矿规律和成矿过程，并建立了描述性成矿模型。这些矿床沿一组平行的走向近东西的深大断裂分布，与成矿有关的镁铁质超镁铁质杂岩体一般不大于5km^2，小的可为一个岩墙。矿化分两种类型：通道型和熔离型。成矿时代为298～270Ma，为中亚成矿带大规模成矿期的组成部分，形成于后碰撞伸展阶段。与这组铜镍硫化物矿床有关的镁铁质-超镁铁质杂岩体可能是早二叠世大面积喷溢岩浆的残留根部或通道部分，可能与地幔柱活动有关。另外，针对区内的地质特征，结合以往找矿的成功经验，对区内进一步的找矿工作提出了一些设想和建议。In the past twenty years 18 Cu-Ni sulfide deposits and occurrences were discovered in the Chinese Tianshan and Altay orogenic belts in northern Xinjiang, China. There are several belts and ore districts along several parallel deep faults. The Kelatongke and several other Cu--Ni mineralized intrusions are located along the Etrix fault, which separates the Altay orogenic belt and Junggar Basin. The Huangshan, Huangshandong, Xiangshan, Tudun, Erhongwa, Tula＇ ergen and Hongling deposits distribute along the Kanggurtag suture, which separates the Qol Tag orogenic belt and Turpan--Hami Basin. The Baishiquan, Tianyu, and Tianxiang deposits are located along the Aqikkuduk fault, which separates the Qol Tag orogenic belt and Middle Tianshan Precambrian terrane. The Poyi, Poshi and Luodong deposits are located along the Hongliuhe fault, which separates the Middle Tianshan Precambrian terrane and the Baishan Variscan rift. Re-Os dating for Cu--Ni sulfide ores reveals that the various ore belts formed in a small age range of 298-282 Ma. This age range is almost identical to the ages of related intrusions and dikes dated by the SHRIMP U-Pb zircon method. Tectonic and geochronological studies explain that the amalgamation of continental blocks mainly occurred during the Late Carboniferous in the Central Asian Orogenic Belt. Large-scale metallogenesis in this region was developed during post-collisional tectonism in the latest Carboniferous to Early Permian. The Cu--Ni sulfide deposits are one component of this large-scale metallogenesis. The Cu--Ni sulfide deposits in northern Xinjiang can be divided into： （1） magma conduit type and （2） differentiated sill type. Some mafic-ultramafic systems exhibit lithological zoning caused by strong differentiation. Stratiform ore bodies are hosted by ultramafic rocks at the base of the magma chamber. Good examples are provided by the Kelatongke, Huangshandong and Poshi deposits. Others, such as the Xiangshan, Baishiquan, Tianyu, and Tula＇ergen deposits, are hosted by magma co

关 键 词：铜镍硫化物矿床 后碰撞 地幔柱 天山-阿尔泰 新疆 

分 类 号：P618.4[天文地球—矿床学] P618.63[天文地球—地质学]