When marine animals die, their shells decay into limestone. when the limestone is exposed ? is released. this is a process known as?

Fossilization

Explanation:

Fossilization represents the various processes of transformation of very old remains or remains, called fossils. Thus, when a living organism dies, the natural process is done by decomposing from the proliferation of bacteria and fungi. An example of fossilization occurs when marine animals die and their shells decompose into limestone. When limestone is exposed it is released.

there is no

explanation:

the answer is:

carbon dioxide