* Zone of Saturation: This zone is below the water table, where all the pore spaces in the rock are filled with water. The constant pressure of the water prevents the dissolution of rock, which is necessary for cavern formation.
* Zone of Aeration: This zone is above the water table and has air pockets within the rock. This allows water to move through the rock, and interact with the rock to cause dissolution.
How Caverns Form:
1. Dissolution: Rainwater, slightly acidic due to dissolved carbon dioxide, seeps into the ground. This acidic water reacts with soluble rock types like limestone, marble, or gypsum, dissolving them over time.
2. Formation of Cracks: Existing cracks in the rock are enlarged by this dissolution process.
3. Expansion: As more water flows through the cracks and dissolves more rock, the cracks widen and deepen, eventually forming caverns.
Important Note: While caverns form in the zone of aeration, the water table can fluctuate. This means that a cavern could be partially or fully submerged at times, depending on rainfall and other factors.
