Types of Sedimentary Rocks Clastic – Chemical - Organic
Clastic Sedimentary Rocks • Clastic sedimentary rocks are composed of rocks that moved because of fluids and settled when the fluid stopped; for example, rocks in a river or stream that then dried up. These rocks are made up of silicate and rock fragments that have become cemented together.
3 Basic Types of Clastic Rocks These three groups are breccias, sandstones and mudrocks. Brecciasare made almost entirely of rock while sandstone is composed of sand and mudrocksof mud. This group is sometimes also known simply as the breccias.
Organic Sedimentary Rocks • Biochemical sedimentary rocks are made up of particles from air or water. These rocks are also known as organic sedimentary rocks because they form as result of something that grew. For example, coal is a biochemical sedimentary rock that comes from a plant.
Chemical Sedimentary Rocks • These rocks form as materials evaporate (what is left over after evaporation). For example, over time seas and ancient oceans dried up. The salt in these seas gathered to form chemical sedimentary rocks including other types of limestone, dolomites and rock salt.