What is the term for sorted material that has been deposited by a stream?

The term for sorted material that has been deposited by a stream is alluvium. This refers to a variety of sedimentary material, such as silt, sand, gravel, and clay, that is carried by water and is deposited in riverbeds, floodplains, and deltas through the natural process of erosion and sedimentation.

Alluvium is characterized by its capacity to be well-sorted, as the flowing water sorts the particles based on size and density during transport. This property of alluvium is significant for various geological and environmental processes, including soil formation, agriculture, and habitat creation in river ecosystems.

In contrast, the other terms listed have different meanings. A sandbank refers specifically to a deposit of sand that may be visible above the water surface and is often subject to the movement of tides and currents, but it does not encompass all types of sediment that streams can carry. Loam is a specific type of soil composed of a balanced mixture of sand, silt, and clay, useful for agriculture but does not relate directly to the sedimentation processes of streams. A delta describes the landform that occurs at the mouth of a river where it meets a body of water, typically formed from accumulated alluvium but is