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白马寨镍铜(铂族)硫化物矿床赋存于二叠纪峨眉山大火成岩省内的基性-超基性侵入岩体之中。矿床地质特征表明矿床可能遭受了二叠纪后的区域构造及热事件的改造作用,这些特征主要有:含矿岩体中部分硫化物与热液蚀变矿物如黑云母、蚀变成因角闪石和绿泥石等紧密共生;硫化矿石相对富集Cu、Pd和Au;含矿岩石的Ar-Ar法同位素坪年龄值为160～170Ma,晚于峨眉山大火成岩省的年龄等。本文提出了两种可能的改造成矿模式:①后期热液沿变形的块状硫化矿的角砾化边缘带入,对原生矿石、岩石产生改造作用形成新的硫化物;②块状-浸染状原生矿石产生变形时,热液流体优先渗入到浸染状矿石中,从而对原生矿石产生改造作用。
The Baimazhai nickel-copper (PGM) sulfide deposits occur in the basic-ultrabasic intrusions in the Permian Emeishan large igneous province. The geological characteristics of the deposit indicate that the deposit may have suffered from post-Permian regional tectonics and alteration of thermal events. Some of these features include: some sulfide and hydrothermal alteration minerals in ore-bearing rock mass, such as biotite, Such as Cu, Pd and Au. The Ar-Ar isotopic ages of ore-bearing rocks are 160 ~ 170Ma, which is later than the age of the Emeishan large igneous province. In this paper, two possible alteration metallogenic models are proposed: (1) Late hydrothermal fluids are brought along the brecciated edge of the deformed massive sulphide ore, resulting in the formation of new sulphides by the remolding of primary ores and rocks; (2) When the original ore is deformed, the hydrothermal fluid infiltrates into the disseminated ore preferentially, so that the primary ore can be reformed.