What is the calcium carbonate cycle?

Answer 1

Plants and animals that secret lime (CaCO3) flourish in tropical seas. Shells Of CaCO3 in many pile up in shallow off shore waters where they cemented themselves into limestone.

Slightly acid grown water is a solvent of limestone, and creates tunnels, caves, and even caverns along cracks or joints in the rock.

Some of the dissolved calcium carbonate is redeposit in caves and caverns stalactites and stalagmites.