AI 中文总结
研究在超镁铁质岩石中发现地幔源岩浆硬石膏，通过其形成年龄及相关同位素体系研究古生代氧化事件影响，揭示深部地幔氧化与巨型矿化关系，表明高镁玄武岩浆可演化为富含铂族元素的斑岩铜矿床系统，将大气氧化与深部地球氧化还原演化相联系。
AI 中文摘要
长期以来岩浆硬石膏被视为斑岩铜矿床中氧化的中长英质岩浆的诊断标志。本文报道了世界上首次在岩浆铂族元素硫化物矿床的超镁铁质岩石中发现地幔源岩浆硬石膏。容纳该硬石膏的单斜辉石岩和角闪石岩形成年龄为408.8Ma，在古生代氧化事件之后不久。硬石膏与火成碳酸盐矿物共存，钙-氧-碳-铁-硫同位素体系表明地幔源因古生代氧化事件被循环的氧化的地表衍生碳酸盐氧化。古生代氧化事件后，更氧化的俯冲带以上地幔与晚古生代造山带岩浆硫化物矿床的出现以及全球斑岩铜矿床频率的迅速增加相关。结果还表明通常被认为是造山带岩浆硫化物矿床母岩浆的高镁玄武岩浆可演化为富含铂族元素的斑岩铜矿床系统。这需要古生代氧化事件后岩浆中有足够高的氧逸度以将硫主要保留为硫酸盐，从而抑制橄榄石分异后的硫化物饱和。研究将大气氧化与深部地球氧化还原演化联系起来，表明地球氧化还原状态的长期变化从根本上影响了关键战略金属硫化物矿床的演化。
英文摘要
Magmatic anhydrite has long been regarded as diagnostic of oxidized intermediate-felsic magmas in porphyry Cu deposits. Here we report the world first occurrence of mantle-derived magmatic anhydrite in ultramafic rock from a magmatic platinum group elements sulfide deposit. The formation age of the clinopyroxenite and hornblnedite hosting this anhydrite is 408.8 Ma, shortly after the Palaeozoic Oxygenation Event (POE). The anhydrite coexists igneous carbonate mineral and systematics Ca-O-C-Fe-S isotopes indicate oxidation of the mantle source by recycled oxidized surface-derived carbonates due to POE. After the POE, the more oxidized supra-subduction mantle is coupled with the emergence of magmatic sulfide deposits in orogenic belt during Late Paleozoic (410-270 Ma) and the rapidly increased frequency of porphyry Cu deposits worldwide. Our results further suggest that high-Mg basaltic magma, typically considered to be parent magma of magmatic sulfide deposits in orogenic belt, can evolve into PGE-enriched porphyry Cu deposit systems. This requires sufficiently high oxygen fugacity in magma after POE to retain sulfur predominantly as sulfate and thereby suppress sulfide saturation after olivine differentiation. Our findings link atmospheric oxygenation to deep Earth redox evolution and suggest that secular changes in Earth's redox state fundamentally influenced the evolution of key strategic metal sulfide deposits.
