新疆萨日达拉金矿地质特征及成因探讨

萨日达拉金矿是新近发现的一个成矿机制和控矿因素都与韧性剪切带密切相关的金矿床，具有独特的成矿特征。文章对萨日达拉金矿的地质特征和作用特征进行了较系统的研究，结合矿区不同岩石的痕量金、自然金和硫化物的成分及硫化物的硫同位素、铅同位素测试结果，对矿床的形成过程进行了详细讨论。研究表明，萨日达拉金矿与胜利达坂韧性剪切带在空间、时间及成因上密切相关，属典型的韧性剪切带型金矿，成矿具有多期、多阶段和多物源的特点，韧性剪切变形、热液活动及其成矿构成了统一的韧性剪切成岩成矿作用过程。对于一个含金韧性剪切带系统，不论是垂向上还是横向上，强变形区段都是成矿元素活化、迁出的区段，而低应变－中等应变部位以及不同强度应变带的过渡部位才是含金流体中的金富集、沉淀成矿的最有利部位，也是寻找大型矿床、矿体的有利部位。

Geological Features and Origin of Saridala Gold Deposit, Xinjiang

The Saridala gold deposit is a newly discovered deposit, whose forming mechanism and ore-controlling factors are closely related to the ductile shear zone , and whose ore-forming features are very unique. Orebodies occur as veins in the border of the large-size gold-bearing ductile shear zone and the transitional area of the secondary shear zones within the major shear zone. From the surface to the depth, the grade of an orebody becomes higher and the thickness becomes wider. The ore belongs to dissemination mylonite type, being mainly of protomylonite and mylonitization type. The ore minerals are mainly pyrite, with a small amount of pyrrhotite as well as rare chalcopyrite, sphalerite and galena. The size of the native gold is 0.01 ~ 0.08 mm and the ratio of Au/(Au+Ag) is 937~982. The multi-periodic activity and multistage evolution as well as multiple ore-forming material sources for mineralization are recognized. Large-scale and intense mineralization is closely related to intense albitization and desilication. Ductile shear deformation, hydrothermal alteration and ore formation constitute a unity of ductile shear rock- and ore-forming processes . Both in vertical direction and along the traverse within an auriferous shear zone system, the intense deformation areas are places where the re mobilization and migration of ore-forming elements occur, while the areas with lower to moderate strain and the transitional places of strain belts with different intensities are the best positions for enrichment and mineralization of gold from the gold-bearing fluids and favorable places in search for large gold deposits and orebodies .