Tuzkan Formation

Tuzkan Fm

Period:

Neogene

Age Interval:

Upper Pliocene, K10

Province:
Kyzylkum Region

Type Locality and Naming

By Lake Tuzkan, northeastern Khanbandytay. B. I. Pinhasov, 1978 (144, p.30). In 1985, a stratotype was published for well 13, located on the northern shore of Lake Tuzkan, in which the deposits of the suite are exposed in the interval 325-404m (145).

Synonym: Tuzkan Suite, Тузканская св.

Lithology and Thickness

It consists of lacustrine unevenly interbedded gray and greenish-gray gypsified siltstone (aleurolites), clays, and gypsumites, containing charred plant detritus and finely dispersed sulfides. Thickness 80-120m.

Lithology Pattern:

Gypsiferous claystone

Relationships and Distribution

Lower contact

It lies at the base of the Upper Pliocene section with erosion on the red beds of the Chulin Fm

Upper contact

It is overlain by ancient alluvium of the paleo-Syrdarya of the Arnasay Fm

Regional extent

Left bank of the Syrdarya River in the central part of the Hungry Steppe and along the southern outskirts of the East Kyzylkum. It is correlated with the lake clays that form the lower part of the Dengizkul Fm section, and with the lower Akchagyl lake-marine deposits of the Kushkanatau Fm of the Southern Aral region.

GeoJSON

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Fossils

Contains Upper Pliocene ostracods - Condoniella suzini Schn., C. marcida Mand., Limnocythere quadrata Mand., Eucypris aff. samgarensis Gr., Cyprinotus vialovi Schn., C. galinus (Brady.); Akchagyl mollusks - Anodonta sp., Limnea sp., Planorbis sp., Avimactra sp.

Age

The suite formed at the beginning of the Late Pliocene in a large lake, which was located in the estuarine part of the paleo-Chirchik and paleo-Angren and covered the Golidnaya Steppe and the southern margin of the Kyzylkum. The lake existed at the beginning of the Akchagyl until the breakthrough of the Paleo-Syrdarya into the Hungry Steppe, the alluvium of which (Arnasay suite) buried the lake deposits of the T. suite under itself. The Upper Pliocene lake layer of the Hungry Steppe was previously attributed by N.V. Pitinov (166) to the B. suite.

Age Span:

Beginning stage:

Piacenzian

Fraction up in beginning stage:

0.5

Beginning date (Ma):

3.09

Ending stage:

Holocene

Fraction up in the ending stage:

1.0

Ending date (Ma):

0.00

Depositional setting

Depositional pattern:

Additional Information

Compiler:

B. I. Pinhasov – In: GeoGPT translation of: “Abduazimova, Z.M. (Ed.), 2001. Stratigraphic Dictionary of Uzbekistan. IMR (Institute of Mineral Resources), Tashkent, 580 pp. (In Russian)”