highly saline lake, Volgograd oblast (province), Russia, near the Russian border with Kazakhstan. The lake occupies an area of 59 square miles (152 square km) and is only 1–2 feet (0.3–0.6 m) deep. It is 60 feet (18 m) below ocean level. Salt, extracted from the lake since the early 18th century, is used for the production of magnesium chloride. Other minerals are located nearby.