is a freshwater lake
A lake is a body of relatively still fresh or salt water of considerable size, localized in a basin, that is surrounded by land. Lakes are inland and not part of the ocean and therefore are distinct from lagoons, and are larger and deeper than ponds. Lakes can be contrasted with rivers or streams,...
, ca. 1,810 km² (700 mi²), in eastern Kazakhstan
Kazakhstan , officially the Republic of Kazakhstan, is a transcontinental country in Central Asia and Eastern Europe. Ranked as the ninth largest country in the world, it is also the world's largest landlocked country; its territory of is greater than Western Europe...
, in a hollow between the Altai and Tarbagatai Mountains
Tarbagatai Mountains is a range of mountains located in the north-western parts of Xinjiang, China and East Kazakhstan....
. It is the largest lake in the East Kazakhstan Province
The lake lies at an altitude of 420 m, is 105 km long and 22–48 km wide, with a maximum depth of 15 m. Its major tributaries are the Kara Irtysh
(Black Irtysh) and Kendyrlyk from the east; its only outlet is the Irtysh River (or White Irtysh). The lake is generally frozen from the beginning of November to the end of April, but still has an abundance of fish. Since the construction of the Bukhtarma dam the lake has risen 6 m (20 ft) above its natural level. As the result, the area of lake essentially increased (nearly doubled: from about 1,800 km² to 3,500 km², or even to 5,000km²), thus, in some sources the lake is indicated as the "part" of artificial reservoir.
The lake has existed since the late Cretaceous Period. The actual age of this lake is particularly important and should be verified. Commonly, Lake Baikal
Lake Baikal is the world's oldest at 30 million years old and deepest lake with an average depth of 744.4 metres.Located in the south of the Russian region of Siberia, between Irkutsk Oblast to the northwest and the Buryat Republic to the southeast, it is the most voluminous freshwater lake in the...
is considered to be the oldest lake on the planet (about 25 million years). The approximate duration of Cretaceous Period is from 136 to 65 million years before present, and, hence, if the Lake Zaysan existed from "the late Cretaceous Period", that means Zaysan must be older than 65 million years, and is the oldest lake on the planet, nearly three times older than Baikal. The direct indication of the Lake Zaysan's age is difficult to find, although some geological studies of the Zaysan Basin have been reviewed. Artificial reservoirs cover large surrounding areas. Modern geological analysis of the entire field, apparently, supports an exceptionally old age for Lake Zaysan.
The first Russian to reach the area was Ivan Bukholts who ascended the Irtysh to build a fort and search for gold. In 1715 he was driven back downriver by the Oirats
Oirats are the westernmost group of the Mongols who unified several tribes origin whose ancestral home is in the Altai region of western Mongolia. Although the Oirats originated in the eastern parts of Central Asia, the most prominent group today is located in the Republic of Kalmykia, a federal...