Which of the following materials is known for being deposited by gravity?

Colluvium is defined as material that has been transported and deposited by the force of gravity, typically accumulating at the base of slopes or hillsides. This type of deposit often consists of a mixture of soil and rock fragments that have moved downslope due to gravitational forces, especially during events such as landslides or the slow creep of soil.

In contrast, loess is a type of silt-sized sediment that is primarily transported by wind and then deposited, while residuum refers to soil or sediment that has formed in place from the weathering of bedrock. Alluvium, on the other hand, describes materials carried and deposited by flowing water, such as rivers or streams. Understanding the origins and transport processes of these materials highlights why colluvium is specifically recognized for its deposition by gravity.