Measurement of reduced peridotite-C-O-H solidus and implications for redox melting of the mantle

摘要: Methane-bearing C-O-H fluids may be important carriers of carbon and hydrogen in the Earth's deeper mantle1,2. It has been proposed that such have a key function genesis kimberlitic magmas diamond subcontinental mantle2–6. Because melting behaviour mantle peridotite presence not accurately located as pressure, temperature oxygen fugacity1,4, it possible to assess validity reduced fluid 'infiltration' models this kind. We report here advances high-pressure buffering techniques allowed fluid-saturated solidus fertile determined 35 kbar. The results show initial saturated with H2O-CH4 dominated occurs at temperatures well above stable continental geotherms, even under quite H2O-rich conditions. This implies fluid-induced beneath continents will restricted regions where CH4 can largely eliminated from by oxidation (redox melting) or geotherm is abnormally high (hot-spot melting), there some combination these processes.