Planetary morphologic processes

Abstract

Geomorphologists have long recognized that the surface of the Earth is shaped by various processes. These processes are generally placed into three primary groups: (a) tectonic processes, involving deformation of the lithosphere; (b) volcanic processes, involving eruptions of magma onto the surface; and (c) gradational processes, involving the erosion, transportation and deposition of surface materials by various agents, such as wind and water, to bring surfaces to a more uniform level. In the planetary context, we must add a fourth major process, impact cratering, which involves collision of solid objects.