Biogenic Rocks

Many marine organisms use chemicals from the water to build their skeletons. After their death, these mineral skeletons often form large clusters, and can serve as a basis for the formation of biogenic sedimentary rocks. They have a different chemical composition.

The most common are carbonate rocks or limestone. They consist of shells of various sea animals, coral skeletons. These include the well-known writing chalk stone.

Siliceous rocks are composed of the skeletons of diatoms, spongioid and radiolarians.

Phosphate biogenic rocks are not common; they can participate in the formation of deposits of minerals – phosphate rocks.

Coal, oil shale, as well as, maybe, oil and bitumen, resulted from the conversion of residues of different plants and animals.

Now we will get ourselves familiar with ancient inhabitants of Earth. Walk forward to the lower showcase number six on the right.