Akterek Formation

Akterek Fm

Period:

Carboniferous

Age Interval:

Middle Carboniferous (Moscovian), F9c, F10

Province:
Fergana

Type Locality and Naming

Along the Akterek River, V. Karachatyr, S. Fergana F.R. Bensh, 1959 (382, p. 74). Stratotype on the left bank of the Dzhingilsai River (Kyrgyzstan).

Synonym: Akterek Suite, Актерекская св., Akterekian suite

Lithology and Thickness

Along F.R. Bensh (110), it is divided into two subsuites. Lower - sandstones, silty claystones, with conglomerates at the base. Thickness 700-720m. Upper - poorly sorted sandstones of various grain sizes, interbedded with siltstone (aleurolites) with lenses and layers of gravelites and conglomerates, less frequently limestones. Thickness 1200-1400m.

Lithology Pattern:

Sandy_claystone

Relationships and Distribution

Lower contact

It lies with erosion on different horizons of the Kalmakbulak Fm and Karatangin Fm

Upper contact

It is conformably overlain by the Dzhilginsay Fm

Regional extent

South Fergana, E. Karachatyr, mainly in Kyrgyzstan, locally in Uzbekistan, Marhamat syncline area.

GeoJSON

null

Fossils

In the lower subsuite - In silty claystones, lenses and layers of clayey and algal-foraminiferal limestones with late Moscovian foraminifera of the Fusulina kamensis-Neostaffella umbilicata (Putrja et Leont.) zone, Ozawainella kurakhovensis Man., O. ex gr. mosquensis Raus., O. pseudoangulata Putrja, Taitzehoella librovitchi (Dutk.), Moellerites aff. paracolaniae (Saf.), Fusulinella tokmovensis Raus. et Dalm., F. praebocki Raus., F. bocki Moell., F, aff. pseudobocki Lee et Chen, F. ex gr. mosquensis Saf., Hemifusulina cf. consobrina Raus., Beedeina pseudoelegans (Chern.), Kamaina cf. kamensis (Saf.), K. ex gr. aspera (Chern.).

Age

Middle Carboniferous (upper Moscovian). To schematically show lithologies according to the thickness it is adjusted from 40% up in Moscovian.

Age Span:

Beginning stage:

Moscovian

Fraction up in beginning stage:

0.4

Beginning date (Ma):

311.90

Ending stage:

Moscovian

Fraction up in the ending stage:

1.0

Ending date (Ma):

307.02

Depositional setting

Depositional pattern:

Additional Information

Compiler:

F.R. Beni – In: GeoGPT translation of: ”Abduazimova, Z.M. (Ed.), 2001. Stratigraphic Dictionary of Uzbekistan. IMR (Institute of Mineral Resources), Tashkent, 580 pp. (In Russian)"