Cenozoic

Cretaceous

Jurassic

Triassic

Permian

Carboniferous

Devonian

Silurian

Ordovician

Cambrian

Neoproterozoic

Main source = Baratov, R.B., et al. (1976). Subdivisions of stratified and intrusive rocks of Tajikistan. Publishing House "Donish", Dushanbe, 269 pp. plus tables. Provided by Dr. Jovid Aminov, Nazarbayev University, Astana, Kazakhstan Translated to English by the GeoGPT group, Zhejiang Lab, Hangzhou, China--see About

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Tashkutan Formation

Tashkutan Fm

Period:

Triassic

Age Interval:

Rhaetian (T3 r?), C2, C2a

Province:
Central W Tajik

Type Locality and Naming

Includes in Dushanbe-west Shirkent-Luchob, east Shirkent-Luchob. They were identified under the name of the Tashkutan suite by I. Levitsky (1935).

Synonym: Tashkutan suite

Reference section:

Lithology and Thickness

The suite consists of bauxites, alunites, bauxite-like clays, coals, carbonaceous rocks. It is developed sporadically, filling individual depressed areas of the pre-Rhaetian landscape. Thickness is 0-60 m.

Lithology Pattern:

Claystone

Relationships and Distribution

Lower contact

It lies with a sharp angular unconformity on various Paleozoic formations, the Khanakin Fm (ханакинской свите), and weathering crusts.

Upper contact

It is overlain in agreement or with erosion by Lower-Middle Jurassic coal-bearing deposits.

Regional extent

They are widespread in the Dushanbe region.

GeoJSON

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Fossils

complex of plant remains collected from a thick coal seam.

Age

The Rhaetian age of the considered deposits was determined by T. A. Sixtelle (Decisions..., 1959; Sixtelle, 1960a) based on a complex of plant remains collected from a thick coal seam. The results of detailed studies (Luchnikov, 1972) and the discovery of plant remains from the bauxite-bearing layer allowed for the suggestion of a Lower Jurassic age for the rocks of the Tashkutan Fm. However, the Stratigraphic Conference in the city. In Samarkand in 1971, a half-hearted decision was made, referring to the lower bauxite-bearing layers of the southern slope of the Gissar Range and the terrigenous coal-bearing package of the Fundarya-Yagnob river basin. On this basis, in this work, the Tashkutan Fm deposits are conditionally attributed to the Rhaetian stage. However, the author believes that only the underlying weathering crusts should be related to the Rhaetian deposits.

Age Span:

Beginning stage:

Rhaetian

Fraction up in beginning stage:

0.0

Beginning date (Ma):

205.74

Ending stage:

Rhaetian

Fraction up in the ending stage:

1.0

Ending date (Ma):

201.36

Depositional setting

Depositional pattern:

Additional Information

Compiler:

Extracted from Baratov, R. B. (1976). Subdivisions of stratified and intrusive rocks of Tajikistan. Donish, Dushanbe, 276.