As a purely scientific term in geology, however, a "massif" is separately and more specifically defined as a section of a planet's crust that is demarcated by faults or flexures. In the movement of the crust, a massif tends to retain its internal structure while being displaced as a whole. A massif is a smaller structural unit than a tectonic plate and is considered the fourth-largest driving force in geomorphology.[2]
The word "massif" originates from French (in which the word also means "massive"), where it is used to refer to a large mountain mass or compact group of connected mountains forming an independent portion of a range. The Face on Mars is an example of an extraterrestrial massif.[3] Massifs may also form underwater, as with the Atlantis Massif.[4]
