Takyr

Takyr

 

(Turkic, “smooth,” “even,” “bare”). (1) The bottom of a lake that dries up periodically; found in areas of clayey soils in desert and semidesert zones. During the wet season, the takyr is covered with a thin layer of water that, upon drying up, exposes the sticky, viscous mud. The mud shrinks as it dries, becoming covered with a crust that is broken up by cracks into variously shaped polygons ranging in size from several square meters to dozens of square kilometers, depending on the composition and degree of salinity of the sediment. A takyr is formed where the water table lies more than 1.5 m below the surface, when excess salts seep into the groundwater and return to the surface through capillaries.

(2) A type of soil that forms in flat, clayey depressions in deserts and semideserts. There are two sharply divided levels in the soil: the upper layer, which is up to 8–10 cm thick and consists of a thick, stratified clay crust that contains no salts, and the underlying layer, which consists of slightly altered saline soil-forming rock. The takyr is almost entirely devoid of vegetation; the flora consists exclusively of algae and lichens.

References in periodicals archive ?
Wang J, Xu X, Xiao G, Wang J (2016) Effect of typical takyr solonetzs reclamation with Flue flue gas desulphurization gypsum and its security assessment.
With the differential replaced on his Toyota Hilux at the night halt, Attiyah and French navigator Matthieu Baumel attacked from a lowly starting position on the road on the 366km loop stage through the Takyr deserts around Astrakhan.
With the differential replaced on his Toyota Hilux at the night halt, al-Attiyah and French navigator Matthieu Baumel attacked from a lowly starting position on the road on the 366km loop stage through the Takyr deserts around Astrakhan.
NATURAL AND ECONOMIC AREAS OF THE LAND OF KAZAKHSTAN, THOUSANDS OF HECTARES (ACCORDING TO THE AGENCY OF LAND RESOURCES OF REPUBLIC OF KAZAKHSTAN) No Natural area Type of soil Total For amount agrarian use 1 Forest-steppe Black soil 758.2 506.2 2 Steppe Black soil, 26448.0 23514.7 South black soil 3 Arid steppe Chestnut soil, Dark 62386.6 55539.6 chestnut soil 4 Semi-desert Light chestnut soil 37258.6 33851.6 5 Desert Brown soil, takyr 112152.3 83601.3 soil, sand 6 Foothill desert Grey-brownish soil, 33486.0 25571.3 and steppe, Dark chestnut desert, soil, Mountain mountain areas soils 7 Total 272490.2 222584.6
Takyr soils consist of two horizons under a dense large-pored surface crust that may be 1 in (3 cm) thick.
Takyr soils are a special type of desert soils; they form on stratified sediments, mainly of clay or loam.
On Tuesday, teams tackle a second loop stage through the Takyr desert around Astrakhan.
Lichens often grow on the edge of takyrs. When the takyrs dry out, the algae dry out too, and their secretions form a film on the takyr surface.
When the takyrs (flat depressions in the desert surface) are full of water, cyanobacteria (mainly of the genera Phormidium and Microcoleus, of the order Oscillatoria) and some green algae (of the orders Protococcales, Chlamydomonales, and Ulotrichales) may become very abundant.
The Qatari ace led from start to finish in Takyr desert stage in Silk Way Rally Tribune News Network DOHA Overdrive Racing's Nasser bin Saleh al Attiyah and French co-driver Matthieu Baumel stayed clear of trouble and moved into an outright lead of 2min 30sec after a challenging loop stage of 311 kilometres through the Takyr desert around Astrakhan in southern Russia on Saturday.
As the takyr is impermeable, the water remains in the depressions until it evaporates.
In the Karakum Desert, water accumulates on the flat clay surfaces in depressions, takyrs, which may cover several square kilometers.