Solutional Caves

Solutional caves are formed when solid rock is dissolved by acidic water. These are the caves most people think of when they think of caves. Most solution caves are found in carbonate rocks like limestone, dolomite, marble, or gypsum. But they may also occur in sandstones, since carbonates often form the "glue" that holds sandstone together. They even occur in salt, which dissolves quickly.

Typically, caves are dissolved while they are below the water table. It is only after the cave is drained and exposed to air that the deposition of secondary mineral features or speleothems may begin.