The nature and origin of the Brucejack epithermal gold deposit, British Columbia

浅成热液金矿拥有世界已知黄金储量的很大一部分，在全球和加拿大的黄金产量中所占份额越来越大。尽管采矿业越来越重视，但自20世纪90年代末以来，新的低温热液金矿的发现率明显下降。尽管许多因素影响了这一下降，但人们普遍认为，需要更好地了解控制低温热液金矿形成的条件和过程，以帮助矿业公司制定更成功的勘探战略。不列颠哥伦比亚省西北部Stewart-Eskay Creek矿区的Brucejack金矿床是最近发现的大型特高品位(高达41000克/吨Au)低或中硫化浅成热液矿床的所在地。在Brucejack的国王谷区域内，勘探钻石钻探已采样了很长一段时间的浅成热液金矿，以支持正在进行的地下勘探开采。这种先进的矿床勘探为研究浅成热液成矿系统中金的来源、物理化学条件和过程提供了一个无与伦比的机会。本项目旨在开发Brucejack矿床的成因模型，方法是通过化学(包括同位素)和岩石学特征描述其矿石矿化和相关的热液蚀变，通过流体包裹体分析确定其矿化流体的组成，通过热力学分析重建控制金矿化的物理化学条件，并定量测试可信的成矿模式。如果成功，该项目将改进现有的浅成热液金矿成因模型和指导其勘探的战略。在当地，这也将增进对Brucejack金矿与Stewart-Eskay Creek矿区邻近世界级斑岩矿床中铜-金矿化之间的成因联系的了解。

Epithermal gold deposits host a significant portion of the world's known gold reserves and are responsible for a growing share of both global and Canadian gold production. Despite increased attention from the mining industry, discovery rates for new epithermal gold deposits have declined markedly since the late 1990s. Although many factors have influenced this decline, it is widely agreed that a better understanding of the conditions and processes controlling the formation of epithermal gold deposits is needed to help mining companies develop more successful exploration strategies. The Brucejack gold deposit in the Stewart-Eskay Creek mining district of northwestern British Columbia is host to a recently discovered, large and exceptionally high-grade (up to 41,000 g/ton Au) low- or intermediate-sulphidation epithermal deposit. Within the Valley of the Kings zone at Brucejack, exploration diamond drill holes have sampled long intervals of epithermal gold mineralisation in support of ongoing exploratory underground mining. Such advanced exploration of the deposit offers an unparalleled opportunity to investigate the source, physico-chemical conditions and processes governing the concentration of gold in epithermal ore-forming systems. This project aims to develop a genetic model for the Brucejack deposit by chemically (including isotopically) and petrographically characterising its ore mineralisation and associated hydrothermal alteration, determining the composition of its mineralising fluids through fluid inclusion analysis, reconstructing the physiochemical conditions that controlled gold mineralisation through thermodynamic analysis and quantitatively testing plausible models of ore formation. If successful, the project will improve on existing models for the genesis of epithermal gold deposits and the strategies that guide their exploration. Locally, it will also improve understanding of the genetic links between gold mineralisation at Brucejack and copper-gold mineralisation in adjacent world-class porphyry deposits in the Stewart-Eskay Creek mining district.