Injection of sCO2 or CO2 dissolved in water with in-situ mineralisation in mafic and ultramafic geological formations was proposed over 30 years ago as a safe way to sequester carbon dioxide in the subsurface by creating calcite, dolomite, and magnesite, siderite and ankerite. Modern technology, improved analytical tools, and successful pilot projects have demonstrated how this is possible. Some applicable rock types include: (1) Basaltic lava containing high concentrations of calcium and magnesium ions; (2) Mantle peridotite containing olivine, brucite, and serpentinite; and (3) Ultramafic plutons and intrusives with high magnesium and iron content.
Prospective Locations with Rock Types:
- Iceland – reactive basalt (e.g., CarbFix project) •Washington State – continental flood basalt (e.g., Wallula project)
- India – continental basaltic lava (e.g., Deccan traps)
- Cyprus, Turkey and Oman – reactive peridotite intrusions (i.e., Troodos, Kizildag, and Semail ophiolites)
- Portugal – gabbros and peridotites (e.g., Sines subvolcanic massif)
In addition to onshore locations, many oceanic locations are suitable for injection of sCO2 or CO2 dissolved in water to create in-situ mineralisation in mafic and ultramafic geological formations, thereby sequestering carbon dioxide in the subsurface. As with onshore locations, calcite, dolomite, magnesite, siderite and ankerite are able to be created. Some applicable oceanic rock types include: (1) oceanic ridges containing serpentinites and peridotites composed of ferromagnesian minerals including olivine altered to serpentine and (2) oceanic igneous plateaus with high magnesium and iron content.
Prospective Oceanic Locations with mafic and ultramafic basaltic magma rocks:
- Mid-oceanic ridges incl. East Pacific Rise; Mid-Atlantic Ridge; Carlsberg Ridge, Central Indian and Mid-Indian Ridge in the Indian Ocean
- Ocean Island Basalts due to intraplate volcanism
- Ontong Java Plateau, north of the Solomon Islands, with a mildly depleted peridotite mantle source and high MgO basalt,
- Caribbean Large Igneous Province consisting of flood basalt with composition similar to the Ontong java Plateau