An experimental study of basalt–seawater–CO2 interaction at 130 °C

Over millions of years, the interaction marine basalt with percolating seawater in low-temperature ocean floor hydrothermal systems leads to formation calcite and aragonite. The presence these minerals basalts provides evidence for substantial CO2 fixation rocks. Here, we report on laboratory experiments study this process under enhanced partial pressures (pCO2) at 130 °C. Mid-ocean-ridge-basalt (MORB) glass was reacted North Atlantic Seawater charged batch lasting up 7 months. For initiated ~2.5 bar pCO2, aragonite are first carbonate form, later followed by only (±siderite ankerite). ~16 magnesite mineral observed form. In total, approximately 20% initial reactors mineralized within five This carbonation rate is similar corresponding rates freshwater-basalt-CO2 during field response CO2-charged freshwater injections SW-Iceland. Our thus suggest that injected into submarine will lead rapid mineralization. Notably, pCO2 tens bars, limiting Mg-rich clays, which might otherwise compete Mg cation pore-space basaltic crust. suggests injection subsurface can be an efficient effective approach long-term safe storage anthropogenic carbon.