hilly upland in central and eastern Kazakhstan, occupying about one-fifth of the republic. It is a peneplain, the mountainous Paleozoic foundation of which had already been worn down into an undulating plain by the beginning of the Mesozoic Era, beginning about 245 million years ago. Low hills are characteristic, and there are extensive depressions occupied by saline Lake Tengiz and other lakes. Isolated mountain massifs, the result of more recent earth movements, rise in the centrally located Karkaraly Mountains and Ulutau Mountains. The climate is continental, and precipitation averages only 4–12 inches (100–300 mm) a year. The river network is therefore scant, with many streams flowing only in spring. The upland is called Saryarqa (“Yellow Range”) because of the colour of the sun-scorched vegetation, which is mainly fescue and feather-grass steppe in the north and of the semidesert variety in the south. There are pine forests on the mountain slopes and important mineral deposits at many sites.