SEDIMENTARY ROCKS

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Sedimentary rocks are types of rock that are formed by the accumulation or deposition of mineral or organic particles at Earth's surface, followed by cementation.

Sedimentation is the collective name for processes that cause these particles to settle in place.

The particles that form a sedimentary rock are called sediment, and may be composed of minerals or organic matter.

The organic matter originated from weathering and erosion of existing rocks, or from the solidification of molten lava blobs erupted by volcanoes.

The organic matter is transported to the place of deposition by water, wind, ice or mass movement.

The minerals were formed by bodies and parts (mainly shells) of dead aquatic organisms, as well as their fecal mass, suspended in water and slowly piling up on the floor of water bodies.

Sedimentation may also occur as dissolved minerals precipitate from water solution.