A unified model for gold mineralisation in accretionary orogens and implications for regional-scale exploration targeting methods
A unified model for gold mineralisation in accretionary orogens and implications for regional-scale exploration targeting methods
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DOI：
10.1007/s00126-012-0402-y
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发表时间：
2012-04-01
影响因子：
4.8
通讯作者：
Begg, Graham C.
中科院分区：
文献类型：
--
作者：
Hronsky, Jon M. A.;Groves, David I.;Begg, Graham C.
增生造山带是长期存在的收缩和伸展边缘构造的场所。它们也是世界上大多数重要金矿的所在地。在增生造山带内有各种各样的存款类型，通常在空间和时间上彼此非常接近。这些矿床包括斑岩和伴生的高硫化金铜银矿床、典型的低硫化金银矿床、以碱性侵入杂岩为中心的低硫化Au矿床、卡林型Au矿床、富Au火山岩块状硫化物矿床、造山型Au矿床、与侵入有关的Au矿床和氧化铁铜Au矿床。这些矿床的空间分布的经验模式表明，必须有基本的一般控制金成矿作用。各种证据表明，控制增生造山带金成矿作用的基本关键因素是区域尺度的、长期的、俯冲前和俯冲同时期的岩石圈地幔的异质富化作用，它成为与成矿作用相关的弧岩浆或热液成分的来源。这一过程提供了一个富金的储层，可以在不同的构造岩浆背景下进入。基于这一概念，提出了一个统一的模式，其中任何类型的主要金存款的形成需要在时间和空间上的三个基本因素的结合：一个肥沃的上地幔源区，一个有利的瞬态再活化事件，和有利的岩石圈尺度的铅垂构造。这一框架为适用于缺乏数据区域的区域范围的实际目标确定方法提供了基础。
Accretionary orogens are the sites of long-lived convergent margin tectonics, both compressional and extensional. They are also the hosts to the majority of the world's important gold deposits. A very diverse range of deposit types occurs within accretionary orogens, commonly in close proximity in space and time to each other. These include porphyry and associated high-sulphidation Au-Cu-Ag deposits, classic low-sulphidation Au-Ag deposits, low-sulphidation Au deposits centred on alkalic intrusive complexes, Carlin-type Au deposits, Au-rich volcanic-hosted massive sulphide deposits, orogenic Au deposits, intrusion-related Au deposits and iron oxide Cu-Au deposits. Empirical patterns of spatial distribution of these deposits suggest there must be fundamental generic controls on gold metallogeny. Various lines of evidence lead to the proposal that the underlying key generic factor controlling accretionary orogen gold metallogeny is regional-scale, long-term, pre- and syn-subduction heterogeneous fertilisation of the lithospheric mantle that becomes a source of mineralisation-associated arc magma or hydrothermal fluid components. This process provides a gold-enriched reservoir that can be accessed later in a diverse range of tectonomagmatic settings. Based on this concept, a unified model is proposed in which the formation of a major gold deposit of any type requires the conjunction in time and space of three essential factors: a fertile upper-mantle source region, a favourable transient remobilisation event, and favourable lithospheric-scale plumbing structure. This framework provides the basis for a practical regional-scale targeting methodology that is applicable to data-poor regions.