Intrusion-related gold systems: the present level of understanding
Intrusion-related gold systems: the present level of understanding
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DOI：
10.1007/s001260100184
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发表时间：
2001-07
影响因子：
4.8
通讯作者：
J. R. Lang;T. Baker
中科院分区：
文献类型：
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作者：
J. R. Lang;T. Baker
本卷提供了一组金矿床的新数据，这些金矿床主要位于侵入体的围岩内或直接侵入体的围岩中，最近被认为包括一个独特的岩浆热液系统。 这些矿床被称为“斑岩型金矿床”（霍利斯特1992; Bakke 1995）、“与侵入体有关的网脉浸染型矿床”（Sillitoe 1991）、“与深成岩有关的金矿床”（纽贝里等人，1988;麦考伊等人，1997）和“与侵入有关的金矿床”（Thompson et al. 1999）。 Lang等人（2000年）更倾向于使用“与侵入体有关的金矿系统”一词，因为它反映了所有岩浆热液环境所共有的一种趋势，即形成的矿石表现出多种类型、金属组合和与其相关侵入中心的空间关联。 虽然还处于起步阶段，但在过去五年中，对与侵入岩有关的金矿系统的调查和勘探已明显加速，部分原因是它们的全球分布以及大量含有30公吨以上黄金资源的矿床（图1）。主要的存款例子包括诺克斯堡（~210 t Au），Donlin Creek（~315吨Au），Pogo（~160吨Au），以及都柏林峡谷、真北和啤酒溪育空地区和阿拉斯加以及捷克共和国的Mokrsko（各约40吨Au）（~120吨Au）、哈萨克斯坦Vasilkovskoe（~300吨Au）、西班牙Salave（~30吨Au）、玻利维亚Korri Kollo（~160吨Au）和澳大利亚Kidston（~140吨Au）。缺乏详细描述的个别侵入相关的金系统，深成省，这些系统的主机，其形成的关键遗传过程，目前限制了我们的能力，无论是制定精确的标准，其定义或制定良好的约束地质和勘探模型。 主要讨论（Sillitoe 1991;霍利斯特1992;纽贝里等人1988和1995; Lang等人1997;麦考伊等人1997; Thompson等人1999; Lang等人2000; Goldfarb等人2000;纽贝里2000）表明，大多数与侵入有关的金矿和金矿区有几个共同的特征，包括：1）中长英质成分的偏碱性侵入体，跨越钛铁矿系列和磁铁矿系列之间的边界，2）碳质热液流体，3）金属组合，其将Au与高Bi、W、As、Mo、Te和/或Sb以及低浓度的贱金属混合，4）硫化物含量低（<5体积%），矿石矿物组合减少，通常包括毒砂、磁黄铁矿和黄铁矿，并且缺乏磁铁矿或赤铁矿，5）区域限制，通常为弱热液蚀变，除了在这些矿床跨越的最浅深度形成的系统外，6）推断或公认的会聚板块边界内侧大陆岩浆活动的构造环境，通常包含碱性，变光钙碱性和过铝质成分的同时代侵入体，7）最好或以前已知的W和/或Sn矿床的岩浆区的位置。 可以确信地包括在中生代大部分时间形成的群中的矿床，但也有人提出包括一些元古代甚至太古代矿床（例如，罗伯特，这卷）。目前公认的定义标准表明，与侵入岩有关的金系统及其相关的深成省在全球范围内广泛分布（图1），但对所含矿床的充分描述现在才开始出现。 阿拉斯加的廷蒂纳金矿带和北美科迪勒拉山脉北方的育空地区（图1）是迄今为止研究最广泛的与侵入有关的金矿系统。这条带长约1000公里...
This volume presents new data on a group of gold deposits that are hosted primarily within or in the immediate wall rocks to intrusions, and which have recently been suggested to comprise a distinct class of magmatic-hydrothermal system. These deposits have been called 'porphyry gold deposits' (Hollister 1992; Bakke 1995), 'intrusion-related stockwork-disseminated deposits' (Sillitoe 1991), 'plutonic-related gold deposits' (Newberry et al., 1988; McCoy et al., 1997) and 'intrusion-related gold deposits' (Thompson et al. 1999). Lang et al. (2000) preferred the term 'intrusion-related gold systems' because it reflects a tendency common to all magmatic-hydrothermal environments to form ores that manifest multiple styles, metal assemblages and spatial associations with their related intrusive centres. Although in its infancy, investigation and exploration of intrusion-related gold systems has accelerated markedly in the last five years, due in part to their global distribution and to the large number of deposits that contain a gold resource of >30 metric tons (Fig. 1). Major deposit examples include Fort Knox (~210 t Au), Donlin Creek (~315 t Au), Pogo (~160 t Au), and Dublin Gulch, True North and Brewery Creek (~40 t Au each) in Yukon and Alaska, as well as Mokrsko, Czech Republic (~120 t Au), Vasilkovskoe, Kazakstan (~300 t Au), Salave, Spain (~30 t Au), Korri Kollo, Bolivia (~160 t Au) and Kidston, Australia (~140 t Au). A paucity of detailed descriptions of individual intrusion-related gold systems, the plutonic provinces that host these systems, and the genetic processes critical to their formation currently limits our ability to either develop precise criteria for their definition or to formulate well-constrained geological and exploration models. The principal discussions (Sillitoe 1991; Hollister 1992; Newberry et al. 1988 and 1995; Lang et al. 1997; McCoy et al. 1997; Thompson et al. 1999; Lang et al. 2000; Goldfarb et al. 2000; Newberry 2000) suggest that there are several features common to most intrusion-related gold deposits and provinces, including: 1) metaluminous, subalkalic intrusions of intermediate to felsic composition that span the boundary between ilmenite- and magnetite-series, 2) carbonic hydrothermal fluids, 3) a metal assemblage which variably combines Au with elevated Bi, W, As, Mo, Te and/or Sb and low concentrations of base metals, 4) a low sulphide content (<5 volume %) with a reduced ore mineral assemblage that typically comprises arsenopyrite, pyrrhotite and pyrite, and which lacks magnetite or hematite, 5) areally restricted, commonly weak hydrothermal alteration, except in systems formed at the shallowest depths spanned by these deposits, 6) a tectonic setting of continental magmatism well-inboard of inferred or recognized convergent plate boundaries, and which commonly contains coeval intrusions of alkalic, metaluminous calc-alkalic and peraluminous compositions, and 7) a location in magmatic provinces best or formerly known for W and/or Sn deposits. Deposits that can be confidently included in the group formed during much of the Phanerozoic, but inclusion of some Proterozoic and even Archean deposits has also been proposed (e.g., Robert, this volume). The defining criteria as presently recognized show that intrusion-related gold systems and their associated plutonic provinces are globally widespread (Fig. 1), but adequate descriptions of the contained deposits are only now beginning to emerge. The Tintina Gold Belt of Alaska and the Yukon Territory in the northern part of the North American Cordillera (Fig. 1) is thus far the most extensively studied intrusion-related gold systems province. This belt is ~1000 km in length …