Speleogenesis is the origin and development of caves, the primary process that determines essential features of the hydrogeology of karst and guides its evolution.
The majority of limestone caves are formed by calcium carbonate dissolution by the solvent action of meteoric waters circulating through the rock.
The exposed limestone then reacts to become calcium bicarbonate which dissolves in the water and is removed from the fault as the solution flows away.
Phreatic passages develop in conditions of complete water-fill meaning that ceilings and walls may be eroded as readily as floors.
It is common to see a younger canyon entrenched in the floor of a phreatic passage, signifying a lowering of the water table.