俄罗斯贝辰加镍-铜硫化物矿床研究进展

The progress in the study of the Pechenga Ni-Cu sulfide deposit, Russia

贝辰加镍-铜硫化物矿床位于俄罗斯北极圈内科拉半岛西北部,是一个世界级镍-铜矿集区。矿集区目前共发现25个含工业矿体的侵入体,分东、西2个矿带,已探明镍资源量470×10^4t,品位1.2%,铜储量350×10^4t,品位0.9%,与俄罗斯诺里尔斯克、加拿大萨德伯里、中国金川等矿床并列为世界级大型铜镍硫化物矿床。贝辰加杂岩体由4套古元古代火山-沉积旋回构成,含矿的为第四套火山-沉积旋回皮尔咖加维建造。矿集区内的火山-沉积作用发生在1940-2500Ma之间,成矿作用发生在1950-1990Ma之间,矿化作用发生在古元古代该地区岩浆演化的晚期阶段。贝辰加镍-铜矿赋矿岩石为富铁苦橄岩,具有高铁、低Al2O3,高Ti O2、Zr和其他不相容元素的特点,强烈富集LREE,地球化学特征类似于板内玄武岩或碱性玄武岩。矿床成矿模式为地幔柱分支分异成的贝辰加岩体侵入裂陷槽,其西部矿体侵入至沉积地层之上,东部矿体侵入到沉积地层内部。硫通过岩浆侵位过程中的同化作用进入岩浆,形成硫化物熔融体,并在后期经历了构造变形、热液叠加等作用后形成了浸染状、角砾状等多种类型的矿化。

Pechenga, a world-class Ni-Cu sulfide deposit, is located in the Kola Peninsula of Russia. The Kola super-deep drilling project is located right at the ore district. 25 intrusions with industrial orebodies have been found in the Pechenga district with toltal resources of 4.7 Mt Ni at 1.2% grade and 3.5 Mt Cu at 0.9% grade, and these orebodies can be assigned to east ore belt and west ore belt. Pechenga, Norilsk（Russia）, Sudbury（Canada） and Jinchuan（China） are all the most famous world-class Cu-Ni sulfide deposits.The Pechenga complex consists of four sedimentary-volcanic cycles, and the orebody is within the fourth sedimentary-volcanic cycle Pilgujarvi Formation. The sedimentary-volcanic activities occurred between 1940 Ma and 2500 Ma, whereas the mineralization occurred in the late period volcanic activities of Pechenga between 1950 Ma and 1990 Ma. The mineralization of Pechenga took place later than that of Norilsk, but earlier than that of Sudbury and Jinchun. The main host rock is ferropicrite, which is characterized by high Fe and low Al2O3, high Ti O2, Zr and other incompatible elements, and strong enrichment of LREE. The ferropicrite is similar to intraplate basalt and alkaline basalt in geochemical characteristics. The metallogenic model of Pechenga can be described as follows：the Pechenga intrusion derived from the branches of mantle plume intruded into rifts, and its west part reached the place above the sedimentary strata, while the east part stopped its migration within the sedimentary strata. The sulfide melt was produced by the assim-ilation of magmatic intrusion, and then a variety of mineralizations were formed.