define alluvium
Colluvium vs alluvium. The definitions of colluvium and alluvium are interdependent and reliant on one another. Distinctions between the two are important in order to properly define the geomorphic processes that have occurred in a 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.