Limestone - A sedimentary rock consisting mostly of calcium carbonate, usually in the form of limy mud, calcareous sand, and/or fossils. Lithification - Solidification of sediment into rock.

Mudstone, shale, and limestone are examples of sedimentary rock likely to contain fossils. As the layers of sediment build up on top of one another, they create a physical timeline. The oldest layers, ...

Limestone, made from calcium carbonate, takes millions of years to form. These sedimentary rocks are born from the decay and ...