Chukurchak Formation

Chukurchak Fm

Period:

Carboniferous

Age Interval:

Lower Carboniferous (Upper Visean – Serpukhovian), CK13

Province:
Chatkal-Kuramin Region

Type Locality and Naming

Along the Chukurchaksai River, upper reaches of the Gavasai River, south slope of the Chatkal Range. S.V. Litovchak et al., 1985.

Synonym: Chukurchak Formation, Чукурчакская св.

Lithology and Thickness

Gray layered and massive, predominantly crystalline limestones with interlayers of dolomites, organogenic-detrital limestones. Thickness 300-500m.

Lithology Pattern:

Dolomitic limestone

Relationships and Distribution

Lower contact

It conformably overlies the Karaulatin Fm

Upper contact

It is unconformably overlain with angular and azimuthal unconformity by the Minbulak Fm (Koksaray Fm?)

Regional extent

South slope of the Chatkal Range, Aktaush and Echki-Too Mountains, basin of the Koksaray and Sumsar Rivers.

GeoJSON

null

Fossils

In the lower part of the formation, Goniatites - Goniatites ex gr. striatus Sow. of the late Visean; foraminifers - Glomospira gordialis Jon, et Park., Ammodiscus multivolutus Reitl., Globivalvulina moderata Reitl., Neoarchaediscus parvus (Raus.), N. gregorii (Dain.), Asteroarchaediscus baschkiricus (Krest. et Theod.)

Age

Fossil data are characteristic of the late Visean and Serpukhovian.

Age Span:

Beginning stage:

Visean

Fraction up in beginning stage:

0.8

Beginning date (Ma):

333.62

Ending stage:

Serpukhovian

Fraction up in the ending stage:

1.0

Ending date (Ma):

323.40

Depositional setting

Depositional pattern:

Additional Information

Compiler:

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