伊朗松贡铜钼矿床研究新进展

New Research on the Genesis of Sungun Porphyry Cu-Mo Deposit in Iran

松贡铜钼矿床位于伊朗西北部,是特提斯成矿域中的超大型斑岩型铜矿床之一。资料表明,松贡矿床矿石储量为6.50亿t,其中含铜0.76%,钼0.01%。斑岩体呈岩株及岩墙状产出,铜钼矿化主要与花岗闪长斑岩有关,石英二长斑岩内也有少部分矿化,在侵入体外围的碳酸盐岩中还有矽卡岩型矿化,松贡斑岩型铜钼矿床的成矿年龄约为20Ma。Cu矿化主要分布在钾化带及部分绢英岩化带,以浸染状的形式出现在脉体及脉体晕中;在浅部,多数硫化物都被淋滤掉,铜蓝、辉铜矿及方辉铜矿等出现在氧化带盖层下面。流体包裹体和稳定同位素(C、H、O、S)研究表明,与矿化有关的流体主要为岩浆水,后期有大气水加入(最多占混合流体的20%)。

Located in northwestern Iran, Sungun porphyry copper-molybdenum deposit is one of giant porphyry copper deposit in the Tethyan metallogenic domain. This paper collected geological data on Sungun porphyry Cu-Mo deposit and summarized the previous study achievments. The Sungun porphyries occur as stocks and dikes. The diorite-granodiorite hosts most of Cu-Mo porphyry-style mineralization, and monzonite-quartz monzonite hosts a little of the mineralization. It is skarn-type mineralization at the contact between Cretaceous limestone and the granodioritic stock. The age of Sungun porphyry Cu-Mo deposit is approximately 20 Ma. Hypogene copper mineralization developed mostly within the potassic and phyllic alteration zone, and exists as disseminations form in veins and veins halo. At the exposed surface of the deposit, most of the sulfide minerals have been leached. Covellite, chalcocite and digenite were concentrated in an underlying supergene zone by downward-percolating ground waters. Fluid inclusion and stable isotope （S, O, H, and C） studies indicate the fluid that is responsible for the potassic alteration and the asso- ciated mineralization was essentially magmatic water, and added by （;200/6 maximum） meteoric water afterward.