👉 Underpile, in geology and archaeology, refers to a layer of soil or rock that is generally lower than the surrounding surface. It is usually composed of organic material such as plant roots, debris from past vegetation, or other organic matter. The term "underpile" was likely first used by ancient civilizations who made use of these layers for various purposes including irrigation, deforestation, and the storage of food. The term has since been applied to a wide range of geological processes, from the
