<正>位于中亚造山带北山褶皱带的甘肃黑山铜镍矿床是国内首例证实为在洋壳俯冲过程中形成的铜镍硫化物矿床(Xie et al.,2012)。以国内标准划分,黑山铜镍硫化物矿床Ni储量达到大型,Cu储量小型,平均品位:Ni 0.6%、Cu 0.27%,其中以1号和4号矿体规模最大。我们通过锆石U-Pb年龄(~357Ma),以及具有MORB和岛弧双重特征的微量元素。
The three most crucial factors for the formation of large and super-large magmatic sulfide deposits are： （1） a large volume of mantle-derived mafic-ultramafic magmas that participated in the formation of the deposits; （2） fractional crystallization and crustal contamination, particularly the input of sulfur from crustal rocks, resulting in sulfide immiscibility and segregation; and （3） the timing of sulfide concentration in the intrusion. The super-large magmatic Ni-Cu sulfide deposits around the world have been found in small mafic-ultramafic intrusions, except for the Sudbury deposit. Studies in the past decade indicated that the intrusions hosting large and super-large magmatic sulfide deposits occur in magma conduits, such as those in China, including Jinchuan （Gansu）, Yangliuping （Sichuan）, Kalatongke （Xinjiang）, and Hongqiling （Jilin）. Magma conduits as open magma systems provide a perfect environment for extensive concentration of immiscible sulfide melts, which have been found to occur along deep regional faults. The origin of many mantle-derived magmas is closely associated with mantle plumes, intracontinental rifts, or post-collisional extension. Although it has been confirmed that sulfide immiscibility results from crustal contamination, grades of sulfide ores are also related to the nature of the parental magmas, the ratio between silicate magma and immiscible sulfide melt, the reaction between the sulfide melts and newly injected silicate magmas, and fractionation of the sulfide melt. The field relationships of the ore-bearing intrusion and the sulfide ore body are controlled by the geological features of the wall rocks. In this paper, we attempt to demonstrate the general characteristics, formation mechanism,tectonic settings, and indicators of magmatic sulfide deposits occurring in magmatic conduits which would provide guidelines for further exploration.
金川超大型岩浆Ni-Cu-(PGE)硫化物矿床位于华北克拉通阿拉善地块西南缘的龙首山隆起带内(汤中立和李文渊,1995)。它是仅次于俄罗斯Noril’sk-Talnakh矿床和加拿大Sudbury矿床之后的世界第三大在采的岩浆Ni硫化物矿床,其成岩及成矿机制长期受到矿床学家的密切关注。最近Song et al.(2012)通过对超基性岩体及其硫化物矿体的岩相学、矿物学及元素地球化学的研究。
