Ergeni

an upland in the southeastern part of the European USSR, in Volgograd and Rostov oblasts and the Kalmyk ASSR. It extends from the Volga near Volgograd to the valley of the Vostochnyi Manych River. Length, about 350 km; width, 20–50 km; altitude, 160–221 m. The hills are composed of clay, limestone, and sandstone, with specific, so-called Ergenian deposits, composed chiefly of sand, in the upper strata. The eastern slope drops abruptly (up to 70–80 m) onto the Caspian Lowland and is broken up by a thick network of gorges. At its foot are the saltwater Sarpin Lakes. The western slope, on the other hand, descends gently and gradually to the valley of the Don River. The watershed in the hills is plateau-like in form, with many sinkholes formed by subsurface erosion. The vegetation is of a semidesert type (wormwood, sheep’s fescue, feather grass, saltwort), growing on light brown soils with patches of solonetses. Willows, oaks, elms, and aspens grow in the ravines of the eastern slopes.