Sedimentary rocks are composed of small bits of rocks (mud, sand, gravel), and sometimes plants and/or animals, that have become 'cemented' together in layers over time.
Composed of bonded grains of eroded rocks. Many break in plate-like fragments.
- Kavanaugh, James. Pocket Naturalist - Geology - An Introduction to familiar Rocks, Minerals, Gemstones & Fossils, Waterford Press: Arizona (2000)