2026-10-11T01:31:02Z https://www.scidb.cn/oai

10.57760/sciencedb.45262 2026-08-05T16:15:45Z

2026-08-05 Mantle-derived magmatic anhydrite in ultramafic rocks reveals deep mantle oxidation and mega-mineralization after Palaeozoic Oxygenation Event doi:10.57760/sciencedb.45262 en Magmatic anhydrite has long been regarded as diagnostic of oxidized intermediate–felsic magmas in porphyry Cu deposits. Here we report the world’s 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 hornblendite hosting this anhydrite is 408.8 ± 2.1 Ma, shortly after the Paleozoic Oxygenation Event (POE). The anhydrite coexists with igneous carbonate minerals and Ca-O-C-Fe-S isotopes indicate oxidation of the mantle source by recycled oxidized surface-derived carbonates due to the POE. After the POE, the more oxidized supra-subduction mantle is coupled with the emergence of magmatic sulfide deposits in the orogenic belt during the Late Paleozoic (410–270 Ma) and a rapidly increased frequency of porphyry Cu deposits worldwide. Our results further suggest that high-Mg basaltic magma, typically considered to be the 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. mantle-derived magmatic anhydrite; Paleozoic Oxygenation Event; magmatic sulfide deposit; PGE-enriched Porphyry Cu deposit; adakitic rock. Yuegao Liu EMBARGO https://creativecommons.org/licenses/by-nc/4.0/ dataset Science Data Bank