mountain range, a northwestern spur of the Tien Shan, in southern Kazakhstan. The name is of Turkic origin, meaning “Black Mountain.” The range extends for 260 miles (420 km) along the Syr Darya (ancient Jaxartes River) and rises to 7,139 feet (2,176 metres), with an average elevation of 3,300–5,000 feet (1,000–1,500 metres). The summits are smooth, and small snow-fed streams flow down the steep slopes in spring. Rich deposits of phosphorites are mined on the range's eastern slopes at Zhangatas and at Kokdzhon; the ores are processed at Shymkent, Zhambyl, and Novo-Zhambyl. Lead and zinc are mined and processed at Achisay and Kentaū.