Don Javier斑岩型铜钼矿床地质特征

Geological characteristics of Don Javier porphyry copper molybdenum deposit

Don Javier矿床是在秘鲁南部新发现的大型斑岩铜钼矿床,位于秘鲁古近纪斑岩型铜钼成矿带内。该矿区主要出露Yarabamba花岗闪长岩体,NW走向的矿体赋存于英安斑岩及其围岩中。主要的矿石矿物有黄铜矿、辉钼矿、辉铜矿等。矿化蚀变由内向外依次为钾化、石英-绢云母化、泥化、青磐岩化,具有典型斑岩型铜矿床的蚀变分带特征。矿体呈筒状,主要分布于石英-绢云母化蚀变带中。矿区内的英安斑岩有4期,其中的前2期与矿化有关,后2期为成矿后侵位。NW向断裂是区内主要的控矿构造,对成岩成矿具有控制作用。与同一成矿带内相邻的Cerro Verde超大型斑岩型铜矿床相比较,两者具有类似的成矿特征。找矿实践表明,强烈的蚀变带、低阻高极化激电异常是找矿的有效标志。

The Don Javier deposit is a large-size porphyry Cu-Mo deposit newly discovered in southern Peru. It is lo- cated in the Palaeogene copper and molybdenum metallogenic belt of Peru. The main outcrop in the mining area is the granodiorite of Yarabamba, and the NW-striking ore body is hosted in the dacite porphyry and its country rock. The principal ore minerals mainly include chalcopyrite, molybdenite and chacocite; from the inner part outwards the mineral alterations are potassic alteration, quartz-sericitization, argillization and propylitization, with typical porphyry copper alteration zonation; the ore body presents cylindrical form and is mainly distributed in the quartz-sericitization zone; the dacite porphyry in the mining area consists of 4 phases of dacite porphyries, among which the former 2 phases are associated with mineralization, whereas the latter 2 phases belong to post mineralization emplacement. The Don Javier deposit is similar to the nearby Cerro Verde deposit, a superlarge copper porphyry deposit in the same metallogenic belt, in metallogenic characteristics. The NW-striking fracture is the main ore-controlling structure, which controlled the rock-forming and ore-forming process. Prospecting practice verifies that intense alteration belts and low resistivity and high IP anomalies are effective indicators in the prospecting activity.