The Tokko () is a river in

Yakutia Sakha, officially the Republic of Sakha (Yakutia), is a republics of Russia, republic of Russia, and the largest federal subject of Russia by area. It is located in the Russian Far East, along the Arctic Ocean, with a population of one million ...

, East Siberia,

Russian Federation Russia, or the Russian Federation, is a country spanning Eastern Europe and North Asia. It is the list of countries and dependencies by area, largest country in the world, and extends across Time in Russia, eleven time zones, sharing Borders ...

. It is the largest tributary of the Chara river in terms of length and area of its basin. The river is long and has a

drainage basin A drainage basin is an area of land in which all flowing surface water converges to a single point, such as a river mouth, or flows into another body of water, such as a lake or ocean. A basin is separated from adjacent basins by a perimeter, ...

of . It is navigable in its final stretch, from its confluence with the Chara. Tokko village is located by the river bank.Tokko
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Great Soviet Encyclopedia The ''Great Soviet Encyclopedia'' (GSE; , ''BSE'') is one of the largest Russian-language encyclopedias, published in the Soviet Union from 1926 to 1990. After 2002, the encyclopedia's data was partially included into the later ''Great Russian Enc ...

:'' in 30 vols. / Ch. ed. A.M. Prokhorov. - 3rd ed. - M. Soviet Encyclopedia, 1969-1978. The Chara-Tokkinskaya group of deposits (Чара-Токкинская группа месторождений), the largest

iron ore Iron ores are rocks and minerals from which metallic iron can be economically extracted. The ores are usually rich in iron oxides and vary in color from dark grey, bright yellow, or deep purple to rusty red. The iron is usually found in the f ...

accumulation in Russia, is located in the Tokko basin.

Rock art In archaeology, rock arts are human-made markings placed on natural surfaces, typically vertical stone surfaces. A high proportion of surviving historic and prehistoric rock art is found in caves or partly enclosed rock shelters; this type al ...

depictions of ancient hunters dating back to the 1st - 2nd millennia BC have been preserved on a

limestone Limestone is a type of carbonate rock, carbonate sedimentary rock which is the main source of the material Lime (material), lime. It is composed mostly of the minerals calcite and aragonite, which are different Polymorphism (materials science) ...

ridge rising to above the river's right bank from its mouth. The waters of the Tokko are rich in fish, including grayling, lenok, taimen, pike and common dace, among other species.Tokko - Water of Russia
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Course

The Tokko is a right tributary of the Chara, of the Lena basin. Its source is in a

glacial lake A glacial lake is a body of water with origins from glacier activity. They are formed when a glacier erodes the land and then melts, filling the depression created by the glacier. Formation Near the end of the last glacial period, roughly 10,0 ...

located on the southeastern slopes of a nameless high peak of the

Udokan Range The Udokan Range () is a mountain range in Sakha Republic (Yakutia) and Zabaykalsky Krai, Russian Federation. The nearest town is Chara (rural locality), Chara.Google Earth There is copper mining in the range at the Udokan mine, part of the Ud ...

, a subrange of the

Stanovoy Highlands The Stanovoy Highlands () or Stanovoy Uplands is a mountain range in the Transbaikal region of Siberia, Russia. Geography The Stanovoy Highlands are a mountainous area between the Patom Highlands to the north and the Vitim Plateau to the south. ...

, very near the border of Transbaikalia.

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In its upper course the Tokko flows northwards across the Olyokma-Chara Plateau in the

Olyokminsky District Olyokminsky District (; , ''Ölüöxüme uluuha'') is an administrativeConstitution of the Sakha Republic and municipalLaw #172-Z #351-III district (raion, or ''ulus''), one of the thirty-four in the Sakha Republic, Russia. It is located in the so ...

through a

U-shaped valley U-shaped valleys, also called trough valleys or glacial troughs, are formed by the process of Glacial period, glaciation. They are characteristic of mountain glaciation in particular. They have a characteristic U shape in cross-section, with s ...

bound by smooth mountains. At about from its mouth the Tokko enters a deep valley where it narrows to a maximum of and forms

rapids Rapids are sections of a river where the river bed has a relatively steep stream gradient, gradient, causing an increase in water velocity and turbulence. Flow, gradient, constriction, and obstacles are four factors that are needed for a rapid t ...

. further downstream, after the confluence of the Choruoda, one of its main tributaries, the Tokko enters a wide

floodplain A floodplain or flood plain or bottomlands is an area of land adjacent to a river. Floodplains stretch from the banks of a river channel to the base of the enclosing valley, and experience flooding during periods of high Discharge (hydrolog ...

where it slows down, divides into arms and forms

meanders A meander is one of a series of regular sinuous curves in the channel of a river or other watercourse. It is produced as a watercourse erodes the sediments of an outer, concave bank ( cut bank or river cliff) and deposits sediments on an inn ...

. Finally it joins the Chara from this river's mouth in the Olyokma. The longest tributaries of the Tokko are the long Choruoda, The long Torgo and the long Teene (Тээнэ) from the right, and the long Kebekte, the long Upper Dzhege (Верхняя Джеге) and the long Ulakhan-Segeeleennekh (Улахан-Сэгэлээннээх) from the left. The river is frozen in most of its length between mid October and mid May, but there are places where

polynya A polynya () is an area of open water surrounded by sea ice. It is now used as a geographical term for an area of unfrozen seawater within otherwise contiguous pack ice or fast ice. It is a loanword from the Russian language, Russian (), whic ...

s form. There are about 1,700 lakes in the basin area of the Tokko.

References

Rivers of the Sakha Republic Stanovoy Highlands {{SakhaRepublic-geo-stub

Course

See also

References