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Earth Materials
Minerals | Rocks

Sedimentary Rocks
Biogenic Sedimentary Rocks

Biogenic sedimentary rocks are primarily composed of plant and animal remains, and include minerals created by organisms, such as corals, molluscs, diatoms or radiolarian which cover the ocean floor and later form limestones or cherts. Coal forms from plant debris accumulated in fresh water swamps which is gradually transformed and carbonized into peat, lignite, bituminous coal and anthracite by increasing burial pressure and temperature.

Sedimentary Structures