How do caves work?

Answer 1

They are not usually used by Man except recreationally. Naturally, sea caves become be refuges for various invertebrates that feed on the dead seaweed that accumulates in them.

In some places sea-caves became popularly associated with 18-19C smugglers using them as hiding-places for their booty, but there is little real evidence for this. If the smugglers knew about a cave, so would the local "Preventy Men" (Customs) & any informants!

Answer 2

the real process contains more details but this is just a main idea

when fish and shellfish die, their bones and shells are compacted and made into limestone (which is also found in toothpaste), due to plate tectonics, the ground rises up and pushes the limestone out of the water. Soil is put over it so animals can live there, then when it rains, the water goes through the soil, and the cracks in the limestone ,picking up carbon dioxide, making it a very mild acid.

The acid (over centuries) eats away the limestone making holes underground.

Answer 3

Not sure what you are asking, but caves are formed by microbes...

+++

Sorry but that's incorrect. Although microbial action may affect a few caves in a very limted way, most caves by far are in limestone, and form by acidic ground-water dissolving the rock. The water is rain-water that has absorbed atmospheric carbon dioxide to form the weak carbonic acid.

Obviously the water has to go somewhere: it escapes eventually through the cave's "rising" or "resurgence" (spring). So caves "work" by carrying rain-water from the hills to springs below.

Answer 4

limestone mostly