Solid fragmental material, or a mass of such material, that originates from weathering of rocks and is transported by, suspended in, or deposited by air, water, or ice, or that is accumulated by other natural agents, such as chemical precipitation from solution or secretion by organisms, and that forms in layers on the Earth's (or other planet's) surface in a loose, unconsolidated form; e.g., sand, gravel, silt, mud.