PLAINS

PLAINS, areas of land, seabed and ocean floor, characterized by weak dismemberment and low absolute elevations. The following types of P. are distinguished on land: by height — lowland (up to 200 m), elevated (up to 500 m), highland (above 500 m); by surface shape — flat, wavy, rolling, hilly, etc; by origin — structural, denudation (peneplains, pediplains, pediments), accumulative (alluvial, proluvial, eolic, outwash, coastal and marine), etc. River valleys, cloughs, ravines, etc are typical. The formation of P. is connected with the geol. structure of the territory. Structural P. are associated with platforms, where the nature of relief is determined by the horizontal bedding of sedimentary cover rocks, e.g. East‑European Plain corresponding to the Eastern European Platform. Denudation P. are formed as a result of the destruction and levelling of mountains, accumulative P. are formed as a result of the accumulation of loose deposits. Within the RB borders the following are distinguished in the relief of the East European Plain: denudation elevated P. (Belebey Upland, Sterlibashevsko­Fyodorovskaya Upland, Obshchiy Syrt, Ufa Plateau) of accumulative and erosion‑denudation origin (Pribelsk rolling and wavy plain). Sakmaro‑Tanalykskaya denudation P. (abs. alt. — 350—500 m) and Kizilo‑Urtazymskaya denudation accumulative (350—400 m) P. are located in the south‑eastern part of the Republic.