Geosequestration of Carbon Dioxide in Deep Saline Aquifers: Hydro-Chemical Considerations DE SILVAGARDIYA PUNCHIHEWAGE DILANTH 2017 Geosequestration of carbon dioxide is a promising technology to mitigate undesirable CO<sub>2</sub> levels in the atmosphere, which is the major cause of global warming. The main aim of this research is to investigate the effect of long-term CO<sub>2</sub>-rock-fluid interactions on aquifer rocks. Assessing long-term CO<sub>2</sub> injectivity and structural integrity of the aquifer and the caprock are key criteria to implement in large scale. Main research findings show that time-dependent degradation of rock minerals cause significant strength reductions through destabilising rock microstructure. Moreover, continuous dissolution and precipitation reactions lead to altering aquifer rock’s pore sizes and the clay content by adversely affecting on flow properties.