Young Blonde Girl On The Sedimentary Rocks

Most authors presently use the term "mudrock" to refer to all rocks composed dominantly of mud. Mudrocks can be divided into siltstones (composed dominantly of silt-sized particles), mudstones (subequal mixture of silt- and clay-sized particles), and claystones (composed mostly of clay-sized particles). Most authors use "shale" is a term for a fissile mudrock (regardless of grain size), although some older literature uses the term "shale" as a synonym for mudrock.
• Biochemical sedimentary rocks
Biochemical sedimentary rocks are created when organisms use materials dissolved in air or water to build their tissue. Examples include:
- Most types of limestone are formed from the calcareous skeletons of organisms such as corals, mollusks, and foraminifera.