加拿大海兰德瓦利斑岩型铜矿研究进展

New Progress on the Highland Valley District,British Columbia,Canada

海兰德瓦利矿集区(Highland Valley district)位于加拿大不列颠哥伦比亚省中南部,是加拿大最大的铜矿产地,该矿集区开采历史悠久,研究资料丰富。矿集区位于太平洋东岸,山间带的克内尔(Quesnel)陆缘弧上,赋存于三叠纪末期侵入的吉琼河(Guichon Creek)岩体中。矿集区中主要有瓦利(Valley)、洛尼克斯(Lornex)、海蒙特(Highmont)、伯利恒(Bethlehem)和JA 5个矿床。矿体主要与晚期的侵入体有关,且受多组断裂交叉复合控制。矿石的构造类型主要为脉状构造、角砾状构造,矿石矿物主要为黄铜矿、斑铜矿、黄铁矿和辉钼矿等,矿化蚀变分带明显,锆石U-Pb年龄和辉钼矿Re-Os年龄以及矿床地球化学特征均显示出岩浆侵位与成矿作用之间有密切的联系,形成时代约205Ma。该铜矿从形成构造背景、形成年代到矿床特征均与中国德兴斑岩型铜矿有相似之处。在矿集区的勘查历史中,感应激发极化法、航磁、水系沉积物以及遥感均对该矿床的找矿做出了很大贡献。对海兰德瓦利矿集区特点及找矿经验的系统总结,可以为我国企业"走出去"及在我国境内寻找同类矿床提供参考。

The Highland Valley copper-molybdenum deposit is located northeast of Vancouver and south- west of Kamloops,in south-central British Columbia. It is the largest operating base metal mine in Canada. The mining area has a long exploration history and rich research data. The ore district lies in the Quesnel continental margin arc terrane,eastern coast of Pacific ocean. It is hosted in the late Upper Triassic calc-alkaline Guichon Creek batholith and contains five major deposits（Valley, Lornex, H ighmont, Bethlehem and JA）. Deposits are related to the youngest intrusive phases of the batholith and controlled by faults. The ores occur mainly as veinlet and breccia structures and the ore minerals include mainly chalcopyrite, born- ite, pyrite and molybdenite. The mineralization and alteration are characterized by obvious zoning. Considering the consistency of U-Pb ages of zircon and Re-Os ages of molybdenite,and the characteristics of petrology and geochemistry,we think that the emplacement time of granodiorite porphyry should be closely related with the formation time of the deposits in Highland Valley district, which is about 205 Ma. From the deposits characteristics, tectonic setting to ore-forming time, Highland Valley district is similar with Dexing porphyry copper deposit in China. In its exploration history,induced polarization, aeromagnetic, stream-sediment and remote sensing made a great contribution to the exploration. The investigation of the characteristics and the successful exploration experience of the Highland Valley district summarized in this paper will offer valuable references for the investment in Canada and the realization of the exploration breakthrough in China.