A batholith is a large, intrusive igneous rock formation that forms from the solidification of magma deep beneath the Earth's surface. Typically, batholiths cover an area greater than 100 square kilometers and are characterized by their coarse-grained texture. They often comprise granite or granodiorite and can be exposed at the surface through erosion over geological time. Batholiths are significant in understanding the geological history and tectonic processes of an area.