Sedimentary Rocks Flashcards
Sedimentary Rocks
A sedimentary rock is formed through the deposition and solidification of sediments. They cover over 75% of the earth’s surface.
Process in which sedimentary rocks are formed
The process of a sedimentary rock being formed is known as lithification. The first stage is the weathering of sediments, then these sediments are transported. After this they are deposited and after compacted. Finally cementation takes place
Role of Water in the Formation of Sedimentary Rocks
Water is the main weathering and erosion agent, producing the grains that eventually become sedimentary rocks.
Cementation
The process of minerals forming around layers of sedimentary rock thus binding them together.
3 Types of Sedimentary Rocks
Clastic, chemical, organic
Clastic Sedimentary Rocks
These are fragments of rock and mineral debris produced by weathering of other rocks on the Earth’s surface. Examples include sandstone, siltstone and shale.
Chemical Sedimentary Rocks
Chemical sedimentary rocks form by chemical precipitation that begins when water traveling through rock dissolves some of the minerals. Examples include limestone, chalk, and rock gypsum.
Organic Sedimentary Rocks
Organic sedimentary rocks form when parts of plants and animals decay in the ground, leaving behind biological material that is compressed and becomes rock. Examples include fossiliferous limestone and coal.
Weathering
Weathering describes the breaking down or dissolving of rocks and minerals on the surface of the Earth
Transportation
Transport refers to the processes by which the sediment is moved along
Deposition
Deposition is the laying down of sediment carried by wind, flowing water, the sea or ice
Root wedging
Tree and other plant roots growing into cracks and wedges underground
