(also peneplain), an area of the earth’s surface with a smooth relief of varying genesis that is formed when exogenic processes prevail over endogenic processes. Leveling plains are characteristic of both platform and folded areas.
There are leveling plains of denudation origin, as well as abrasion, abrasion-aggradation, and denudation-erosion plains. Leveling plains of denudation, as a rule, are articulated with aggradation marine and alluvial plains, which can be considered to be elements of complex polygenetic (denudation-aggradation) leveling plains. The age of the leveling plains corresponds to the period of the fullest planation of the relief, which is usually broken by intensive uplifting that results in the breaking up of the surface.
The principal method for establishing the stages in the geo-morphological history of large territories involves the identification of leveling plains. Their structure is studied, and their age determined. In addition to having great theoretical value, an analysis of leveling plains is of significant practical interest, since a number of minerals, including bauxites and iron ores, are related to them.
To systematize and generalize data on the leveling plains in the Soviet Union, the Map of Leveling Plains and Weathering Crusts of the USSR has been compiled on a scale of 1:2,500,000 (editors in chief I. P. Gerasimov and A. V. Sidorenko, 1972).