* Dissolution: The caverns were formed over millions of years by the dissolving action of acidic groundwater on the soluble rock, primarily gypsum (calcium sulfate). Rainwater absorbs carbon dioxide from the atmosphere, creating a weak carbonic acid. This acidic water percolates through the ground, dissolving the gypsum, creating large underground cavities.
* Physical weathering is the breakdown of rocks due to physical forces like:
* Frost wedging: Water freezing and expanding in cracks, breaking the rock apart. This is not a significant factor in the Carlsbad Caverns.
* Abrasion: Rocks grinding against each other, like in a river bed. This is not relevant to the formation of the Carlsbad Caverns.
* Thermal expansion/contraction: Rocks expanding and contracting with temperature changes. This can cause some cracking, but it's not the primary process involved in cave formation.
While physical weathering may play a minor role in the Carlsbad Caverns, dissolution is the dominant process responsible for their formation.
