Aktash Formation

Aktash Fm

Period:

Carboniferous

Age Interval:

Lower Carboniferous (Visean), CK13

Province:
Chatkal-Kuramin Region

Type Locality and Naming

Along g. Aktash, southern slope of the Chatkalsky hr. S.V. Litovchak et al., 1985 (460, p. 160).

Synonym: Aktashskaya Svita, Aktaush suite, Акташская св.

Lithology and Thickness

In the lower part, layered dark gray to black limestones with frequent lenses, constrictions, and layers of black cherts. Thickness 140-190 to 270 m. In the upper part, coarse-layered gray oolitic and crinoidal limestones. Thickness 145-195m.

Lithology Pattern:

Oolitic limestone

Relationships and Distribution

Lower contact

Lies conformably on the limestones of the Dongusay Fm

Upper contact

It is conformably overlain by the Karaulatin Fm

Regional extent

Chatkalsky hr., p. Aktash, interfluve of the Sumstar-Distarsay rivers, basin of the Koksarek stream; Echki-Too (Echchilik-Tau).

GeoJSON

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Fossils

Contains foraminifers - Tuberitina magna Pojar., Hyperammina elegans Raus., Eostaffella ikensis Viss.; Lower Visean brachiopods Spirifer striatus (Mart.), S. ischimicus (Litv.), Dictyoclostus deruptus (Rom.).

Age

Fossil data indicates Lower Visean

Age Span:

Beginning stage:

Visean

Fraction up in beginning stage:

0.2

Beginning date (Ma):

343.45

Ending stage:

Visean

Fraction up in the ending stage:

0.6

Ending date (Ma):

336.90

Depositional setting

Depositional pattern:

Additional Information

Compiler:

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