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1. n. [Geology]

The range of sedimentary grain sizes that occurs in sediment or sedimentary rock. The term also refers to the process by which sediments of similar size are naturally segregated during transport and deposition according to the velocity and transporting medium. Well-sorted sediments are of similar size (such as desert sand), while poorly-sorted sediments have a wide range of grain sizes (as in a glacial till). A well-sorted sandstone tends to have greater porosity than a poorly sorted sandstone because of the lack of grains small enough to fill its pores. Conglomerates tend to be poorly sorted rocks, with particles ranging from boulder size to clay size.

See: cubic packingdepositional energyporosityrhombohedral packingsedimentUdden-Wentworth scale

Clastic sediment
Schematic diagram of sediments and Udden-Wentworth scale.

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