Abstract Despite many decades of study, the genesis of orogenic gold deposits remains in debate. One aspect of this debate concerns the origin of the mineralising fluids. Two important constraints are that the fluids are sulphur and CO2 bearing and that high fluid fluxes are maintained in a spatially localised environment for a relatively short period of time whereas crustal metamorphism/decarbonation operates over many millions of years, the source is not localised and is of regional extent. In this paper we explore the devolatilization of a subducting slab material using coupled petrological thermo-mechanical numerical approach that takes into account dehydration and decarbonation processes. Recent phase equilibria calculations show that decarbonisation of the slab requires much higher temperatures that normally occurs within subduction zones and the devolatilization site in the slab is spatially and temporally localised during slab roll-back or within a hot orogen when the slab material is incorporated into the overriding plate. We also investigate the plausibility of large gold sources in the collisional and back-arc environments.

中文翻译：

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二氧化碳作为造山金来源的代表

摘要 尽管经过数十年的研究，造山型金矿床的成因仍存在争议。这场辩论的一个方面涉及矿化液的起源。两个重要的限制是流体是含硫和 CO2 的，高流体通量在空间局部环境中保持相对较短的时间，而地壳变质/脱碳作用持续数百万年，源不是局部的，而是区域范围。在本文中，我们使用耦合的岩石学热机械数值方法探讨了俯冲板片材料的脱挥发分，该方法考虑了脱水和脱碳过程。最近的相平衡计算表明，板坯的脱碳需要更高的温度，这通常发生在俯冲带内，并且板坯中的脱挥发分位置在板坯回滚期间或在热造山带内，当板坯材料被纳入覆盖板。我们还调查了碰撞和弧后环境中大型金源的合理性。