How were the caves in the Grand Canyon formed?

Answer 1

Water wears away the rock by a combination of dissolving it and erosion. They usually start with small cracks, the water dissolves bits of the limestone and make them bigger and bigger. Eventually the flow is strong enough that particles of dirt and sand help with the erosion. Then typically the water table shifts due to a change in climate or earthquake and the cave is left dry. Water leaching through into the cave can create huge flows of rock hard deposits that make the beautiful formations often found in caves.

Answer 2

Caves can form in a variety of ways, but most caves are dissolutional and are initially formed by chemical weathering of surface rock, usually limestone, by carbonic acid contained in rainwater. As chemical weathering continues, mechanical weathering joins in the fun to further attack and widen joints and fissures in what is usually soluble sedimentary rock, like limestone.

Some other types of caves are formed by percolating sulfuric acid, flowing lava, flowing water in glaciers, wave action, and particle abrasion.

Answer 3

I'm not 100% certain which caves you mean by "caves in the grand canyon," so I can't answer it for sure, but based on the geology of the region they're most likely either wind caves (very shallow caves in the side of a cliff) or solution caves (can be fairly deep caves formed in, usually, limestone or dolomite).

Answer 4

Carlsbad Caverns are made of limestone. It is near an oil reserve so hydrogen sulfide from the oil formed sulfuric acid which ate some of the limestone.