River sorting is a process that occurs in which deposits?

• A. Eluvial deposits
• B. Bedrock
• C. Alluvial deposits
• D. Evaporites

Answer: (C)

River sorting is the process by which flowing water selects and deposits particles according to size and density as its energy changes. This happens in alluvial deposits, which are sediments laid down by rivers and streams in channels, floodplains, and deltas. As the river slows, coarser grains drop out first while finer material can be carried farther or settle in quieter areas, producing characteristic grain-size layering. Bedrock is solid and not deposited by transport, evaporites form from evaporation in arid basins, and eluvial deposits consist of weathered material near the surface not primarily moved and sorted by running water. So, the deposits where river sorting occurs are alluvial deposits.