Colluvium specific geological setting. Alluvium is sand, clay, or other similar detrital material deposited by running water. The distinction between colluvium and alluvium relates to the involvement of running water. Alluvium specifically refers to the geomorphic processes involved with flowing water and so alluvium is generally fine-grained clay and silt material that has the capacity to be entrained in water currents and eventually deposited. For these same reasons, alluvium is also generally well sorted material while colluvium is not. Colluvium Colluvium (also colluvial material or colluvial soil) is a general name for loose, unconsolidated sediments that have been deposited at the
Parent material eventually settle near the mouth of the river. Lake deposited parent material is called lacustrine parent material. Beach ridges may be present where glacial lakes once washed up sand. Lacustrine material is well sorted and fine-textured, having finer silts and clays. Soils formed from lacustrine parent material have low permeability in part because of this high clay content. Ocean deposited parent materials, called marine sediments, are collections of material that have been carried by rivers and streams to the ocean and eventually sink to the bottom. Such materials can vary in texture. Collections of large rock fragments that have traveled