The primary reaction sequence in limestone dissolution is the following::H2O + CO2 → H2CO3:CaCO3 → Ca2+ + CO32−:CO32− + H2CO3 → 2 HCO3−:CaCO3 + H2CO3 → Ca2+ + 2 HCO3−In particular and very rare conditions such as encountered in the past in Lechuguilla Cave in New Mexico (and more recently in the Frasassi Caves in Italy), other mechanisms may also play a role.
Ko dež doseže tla in gre skozi tla, lahko zagotovi veliko več CO2 in dobimo raztopino šibke ogljikove kisline, ki raztaplja kalcijev karbonat.