Tyulkubash Formation

Tyulkubash Fm

Period:

Devonian

Age Interval:

Middle-Upper Devonian, CK3, CK5, CK7

Province:
Chatkal-Kuramin Region

Type Locality and Naming

Along the Tyulkubash mountain, Central Karatau, South Kazakhstan. V.N. Weber, 1935 (134, p. 55-56) in Central Karatau.

Synonym: Tyulkubash Suite, Тюлькубашская св.

Lithology and Thickness

At the base, there are polymictic conglomerates, gravelites with layers of sandstones. The main part of the formation consists of red, pinkish-gray, brown, grayish-yellow polymictic, quartz, and arkosic sandstones of varying grain sizes. Cross-bedding is characteristic. There are layers and lenses of siltstone (aleurolites), gravelites, conglomerates, less frequently argillites, clay shales, limestones, marls, and dolomites. Thickness: 100-450m (Pskem Range) to 2500m (Ugam Range).

Lithology Pattern:

Sandstone

Relationships and Distribution

Lower contact

It lies sharply unconformably on the eroded surface of Lower-Middle Devonian volcanics and older formations

Upper contact

It is conformably overlain by the carbonate Tepar Fm (165; 441).

Regional extent

Chatkal Range. Within the territory of Uzbekistan, it is observed in the border region with Kyrgyzstan.

GeoJSON

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Fossils

In the upper part of the sandstones, remains of armored fish from the genus Bothrilolepis sp. have been found; in the limestones, foraminifers - Umbella bella Masl. and brachiopods - Cyrtospirifer archiaci Murch., C. brodi Wen., and others

Age

Fossil data indicates the Frasnian age of the deposits (457).

Age Span:

Beginning stage:

Frasnian

Fraction up in beginning stage:

0.0

Beginning date (Ma):

378.90

Ending stage:

Famennian

Fraction up in the ending stage:

0.6

Ending date (Ma):

364.02

Depositional setting

Depositional pattern:

Additional Information

Compiler:

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