Geochemical processes and environmental implications of carbon mineralization in basalts: A comprehensive review

The growing urgency to mitigate global warming has driven the development of Carbon Capture, Utilization, and Storage (CCUS) technologies. Among these, carbon mineralization in basalt formations offers a permanent and secure pathway for CO₂ storage. This review synthesizes recent advances in carbon mineralization in basalt, emphasizing geochemical mechanisms, fluid-rock interactions, and environmental implications. Two distinct pathways are identified: dissolved CO₂ injection, which produces uniform reaction fronts via bulk transport, and supercritical CO₂ injection, where thin-film interfacial reactions dominate. Fluid chemistry evolution is strongly temperature-dependent, with systematic trends in pH, Ca, Mg, and Fe concentrations, controlling carbonate and clay precipitation. Porosity and permeability changes reflect a dynamic balance between dissolution-driven pore enlargement and precipitation-induced clogging, with field trials generally showing minimal alteration while laboratory studies reveal contrasting outcomes. Reactive transport models highlight the importance of mineralogical heterogeneity, feedbacks, and chemo-mechanical coupling in governing long-term reservoir behaviour. By linking molecular-scale interfacial reactions with continuum-scale hydrodynamics and petrophysical evolution, this review develops an integrated framework for understanding CO₂-basalt systems and highlights the importance of mechanistic pathways, temperature-dependent fluid chemistry, and porosity-permeability feedbacks, providing new insights for optimizing injection strategies and improving predictive modelling toward large-scale, environmentally safe basalt carbon mineralization.