新疆哈密黄山铜镍硫化物矿床地质特征

黄山铜镍硫化物矿床产于黄山镁铁—超镁铁杂岩体中.岩体分异良好,由七个岩相带组成,主要矿体产于辉橄岩相底部,呈盆状;主要金属矿物有镍黄铁矿、黄铜矿、紫硫镍矿及磁黄铁矿;矿石大都为浸染状贫矿石.文中着重讨论成矿物质来源、成矿元素丰度.成矿物化条件及成矿过程和成矿模式.

GEOLOGIC CHARACTERISTICS OF HUANGSHAN CU, NI- SULPHIDE DEPOSIT IN HAMI, XINJIANG

Huangshan Gu.Ni-sulphide deposit, occuring in mafic-ultramafic composit rock body and formed in second intrusive stage, is the largest of the Hami Huangshan Cu-Ni mineralization belt. It is derived from picrite-tholeiitic magma resulting from partial melting of upper mantle which rises along the fracture zone into crust forming a central magma chamber. Owing to liquid-gravitative differentiation and liquid immiscibility of metal-sulphide in a stable structural enviroment, the Iherzolitic magma being rich in metal-sulphide are concentrated at the bottom. The reactivity of structure leads to uplift of the differentiated magma from central magma chamber to the upper crust of about 8km in depth. Flowing differentiation, on-sit-liquid immiscibility and crystallization differentiation work together, causing the sulphide meltings to settle down and form large bottom ore bodies, mainly appearing as pot-shaped, partly as banging ore bodies being small on scale and having no industrial significances. Most ores are low-grade disseminated ores in which the main metal-sulphide minerals are pyrrhotite, pentlandite, chalcopyrite, violarite, magnetite and pyrite.