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Glossary - Sedimentary rocks

Sedimentary rocks

Sedimentary rocks are formed from pre-existing rocks or pieces of once-living organisms. Clastic sedimentary rocks are made up of pieces (clasts) of pre-existing rocks. Pieces of rock are loosened by weathering, then transported to some basin or depression where sediment is trapped. If the sediment is buried deeply, it becomes compacted and cemented, forming sedimentary rock.

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