岩浆Cu-Ni-PGE矿床研究现状及发展趋势

从全球视野分析研究了世界岩浆铜镍硫化物矿床的大地构造分布和成岩成矿类型,特别是通过上世纪末新发现的加拿大Voisey′s Bay矿床与俄罗斯Noril′sk等世界级矿床特征的对比研究,突出强调了大火成岩省(LIPs)对大规模岩浆硫化物矿床形成的意义,从更加宏观的角度审视了世界级岩浆硫化物矿床形成的地质背景和岩浆作用条件,为中国金川等岩浆Cu-Ni-PGE硫化物矿床的深入研究提供了参照背景。评述分析了当代岩浆硫化物矿床成矿研究中,幔源岩浆中硫化物液相不混溶(熔离)的演化轨迹,对岩浆萃取地壳中的硫改变硫化物饱和度促成不混溶作用发生的可能性和条件进行了探讨,进一步讨论了岩浆演化过程中,亲铜元素(Ni、Cu、Co、Pt和Pd等)进入硫化物液相成为金属硫化物或先期进入先结晶的橄榄石、辉石矿物成为氧化物的物理化学行为,并通过加拿大Sudbury陨石撞击构造成因矿床复合热液对硫化物矿体形成贡献的讨论,提出了热液作用对岩浆硫化物矿床成矿的可能贡献。分析判断了中国岩浆Cu-Ni-PGE硫化物矿床的成矿特点和金川超大型岩浆Cu-Ni-PGE矿床外围的找矿潜力。

The Current Status and Prospect on Magmatic Ni-Cu-PGE Deposits

From the global eyeshot this paper researches the geotectonic distribution and diagenetic metallogenic types of the magmatic sulfide deposits in the world. Especially through comparing the characteristic of the Voisey's Bay deposit in Canada, which is newly found at the end of 20st century, with the world-class Noril'sk deposit in Russia, this paper emphasizes on the significance of LIPs for the cosmically forming of magmatic sulfide deposit, and from more macroscopical angle survey the geologic setting and magmatism's condition of the forming of the world-class magma sulfide deposit, for supplying consulting background for deeply researching on magmatic Ni-Cu-PGE sulfide deposits such as Jinchuan in China. During the process of contemporary ore-forming researching of magmatic sulfide deposits, this paper appraises and analyzes the evolutionary track of sulfide fluid immisciblility in mantle-derived magma, and discusses the feasibility and conditions of immisciblility when magma leached sulfur in crust and changed the sulfide saturation. And it also discusses the physicochemical behavior that chalcophile elements (Ni, Cu, Co, Pt, Pd, and so on ) enter sulfide fluid with forming metallic sulfide or in advance enter earlier crystallizating olivine,pyroxene minerals with becoming oxide in magmatic evolution. Through the discussion of the contribution of composite hydrothermal fluids to the forming of sulfide orebody in Sudbury meteorite impacting structural genetic deposit, this paper bring forward the possible contribution of hydrothermal process to the mineralization of magmatic sulfide deposit. We analyses and judges metallogentic characteristics of magmatic Ni-Cu-PGE sulfide deposits in China and the prospecting potentiality of the periphery of Jinchuan super-large magmatic Ni-Cu-PGE sulfide deposit.