Pei Mountains

highlands in Central Asia in China between the basin of Lake Lop Nor in the west and the Joshui River (Etsin-Gol) in the east. They stretch in a latitudinal direction for about 700 km. They are about 250 km wide and are up to 2,791 m high (Mount Matsungshan). The highlands consist of a series of mainly low-mountain, strongly weathered block massifs and ridges, mainly formed of ancient metamorphic and crystalline rocks, and the intermontane saddles dividing them, which are filled with Cenozoic, coarsely ground deposits. Wind weathering is widespread. The climate is temperate and extraordinarily dry. Precipitation is 40 to 80 mm a year. Sandstorms are frequent. There are almost no surface waters. In the depressions there are wells in some places, mostly with brackish water. The landscape is dominated by rocky desert forms. In places where there are shallow-lying groundwaters there are meadow solonchaks, and, occasionally, tugai vegetation (bottomland complex with forests, bushes, and meadows).