Grain-size frequency distributions differ characteristically among clastic sediments deposited in different environments: shingle (gravel) beaches are dominated by very coarse clasts near the pebble/cobble range; sandy river channel deposits show a moderately well-sorted sand-sized mode; wind-blown dune sands are typically very well sorted, fine-to-medium sand with a narrow, sharply peaked distribution; and loess (wind-blown silt) is dominated by very fine, silt-sized particles, the finest of the group.