Here's how it works:
1. Rainwater: Rainwater absorbs carbon dioxide from the atmosphere, forming a weak solution of carbonic acid.
2. Dissolving Limestone: This slightly acidic rainwater seeps into the ground and comes into contact with limestone (calcium carbonate, CaCO₃). The carbonic acid reacts with the limestone, dissolving it.
3. Chemical Reaction: The reaction produces calcium bicarbonate (Ca(HCO₃)₂, which is soluble in water.
4. Cave Formation: Over time, this process of dissolving limestone creates underground cavities and tunnels, eventually forming caves.
While carbonic acid is the primary culprit, other acids like sulfuric acid can also contribute to cave formation, especially in areas with volcanic activity.
