科马提岩类岩浆熔离硫化镍矿石建造

与科马提岩(超铁镁火山岩)类有关的硫化镍矿床是70年代提出的新的矿床类型,它在硫化镍矿床中约占54%;占世界镍储量的22.7%,占1979年世界开采量的26.1%;它主要产于太古代绿岩带中,但其他年代地层中也有产出。成矿母岩和赋矿围岩均为科马提岩,其鬣刺结构和流层状构造特别发育。本型矿石主要由磁黄铁矿、镍黄铁矿、黄铁矿、黄铜矿、磁铁矿等组成,较之与辉长岩类有关的铜镍硫化物矿床,其镍黄铁矿含量远大于黄铜矿,Ni/Cu比值在10-70之间(与辉长岩类有关的矿床为17)。本文还介绍了本型矿石建造的矿物共生组合、组构、矿体的形状与产状、成矿物质的来源,以及矿床的成因。

NICKEL SULFIDE FORMATION OF KOMATIITE MAGMATIC LIQUATION

Nickel sulfide deposits related to komatiitic rocks have been recognized as the new type of nickel deposit since 1970s, currently con-sisting of 54% of the total number of nickel sulfide deposits and 22.7% of Ni reserves in the world and 26.1% of the world's Ni ex-ploitation. The komatiite nickel sulfide formation mainly occurs in Archaean greenstones, but also in other stratigraphy. Both source rockand country rock of the ore formation are komatiite with well developed spinifex texture and flowage-layering structure. The mineralogical composition of ores is pentlandite, pyrite, chalcopyrite and magnetite. To compare with sulfide ores related togabbro, bere the content of pentlandite is much more than chalcopyrite and the Ni/Cu ratio is ranging from 10 to 70. where in gabbroicores the ratio is only 1 to 7. Mineral paragenesis, ore fabrics. form and occrrence of ore bodies, source of metallogenetic material, and the origin of the ore de-posits are also introduced in this paper.