Finely divided rock-derived material containing an admixture of organic matter and capable of supporting vegetation. Soils are independent natural bodies, each with a unique morphology resulting from a particular combination of climate, living plants and animals, parent rock materials, relief, the ground waters, and age. Soils support plants, occupy large portions of the Earth's surface, and have shape, area, breadth, width, and depth. (However, the term “soil” as used by engineers means unconsolidated rock material.)