Geomorphology

Synonyms

Landscape geology; Physical geography

Definitions

Uniformitarianism. The assumption that processes operating at present are the same processes that have operated in the past – essentially that “the present is the key to the past.” The utility of the uniformitarianist paradigm for geomorphology depends on the assumption of a roughly constant range of surface environments, which is not true over on timescales comparable to the age of the planet.

Baselevel. The lowest level to which a stream, river, or groundwater can flow. For large rivers it is usually at the river mouth, typically sea level. For enclosed drainage basins, baselevel can be elevated or “perched.” For most landscapes baselevel limits the depth of erosion.

Pediment. Gently sloping surface of bedrock, often disjoint from steeply sloping mountain foothills, which forms a steady-state equilibrium surface of transport for laminar sheetwash flows. They are often veneered by alluvial gravels or soils.

Scarp. Sometimes...