Potential for carbon dioxide sequestration in volcanic rocks of the North Atlantic Igneous Province

In the quest to achieve the objectives of the Paris Agreement, which aim to restrict anthropogenic warming to 1.5–2.0°C this century, carbon capture and storage (CCS) plays an indispensable role. The majority of CCS projects are focussed on the injection of carbon dioxide (CO₂) into porous sedimentary rocks at greater than 1 km depth; these require impermeable overlying rocks to stop the CO₂ escaping to the surface. An alternative approach, however, involves the injection of CO₂ into reactive rocks (e.g. mafic or ultramafic lithologies) leading to carbonate mineralisation; this process permanently locks carbon away with minimal risk of it re-entering the atmosphere. The CarbFix project in Iceland has made significant strides in demonstrating the viability of this approach by injecting CO₂ into basalt lava flows. The project is, however, on a relatively small scale and there are uncertainties regarding the feasibility of scaling up this technology for widespread commercial use, such as utilising the large volumes of volcanic rock formations of the North Atlantic Igneous Province (NAIP). These volcanic rock formations vary significantly in terms of facies, mineral composition, porosity and permeability, all factors that need to be addressed in adopting the CarbFix approach. The potential of carbon mineralisation within the NAIP will be explored and the challenges faced will be discussed.