Akbulak-Carb-L Formation

Akbulak-Carb-L Fm

Period:

Carboniferous

Age Interval:

Tournaisian, CK5

Province:
Chatkal-Kuramin Region

Type Locality and Naming

Along the Akbulak River, left tributary of the Chatkal River, Chatkal ridge. I.M. Nigmadzhanov in 1986. Stratotype in the lower reaches of the Akbulak River.

Synonym: Akbulakskaya Svita, Акбулакская св.

Lithology and Thickness

Light gray, massive-thick-bedded limestones, strongly recrystallized, locally to marbles. The suite includes reef and biogenic mounds of the "Akbulak" type, tracing the northern lateral boundary of the suite thickness from 100-120 m in sections where organic buildups are absent, to 400-500 m, where they appear.

Lithology Pattern:

Limestone

Relationships and Distribution

Lower contact

With angular unconformity and conglomerate-breccias at the base, it lies on the Chavatin Fm

Upper contact

The diachroneity of the upper boundary is established within the conodont zones crenulata and punctatus. And is conformably overlain by the Kulosyn Fm

Regional extent

Predominantly Chatkal Range, basin of left tributaries of the Chatkal River, Akbulak, Mazar-Sai, and Sargardon rivers. Laterally to the north, it transitions into the Koksuy Fm. Previously, the deposits of the A. suite were attributed to the Temirbastau Fm, Sargardon Fm, or combined Temirbastau Fm and Sargardon Fm.

GeoJSON

null

Fossils

Contains conodonts - Siphonodella duplicata (B. et M.), S. obsoleta Hass., Gnathodus punctatus (Coop.); brachiopods - Leptagonia analoga Phill., Camarotoechia cf. elegantula Row.

Age

The age range of the suite is variable. The stratigraphic position of the suite is clearly defined in the middle part of the Tournaisian stage.

Age Span:

Beginning stage:

Tournaisian

Fraction up in beginning stage:

0.4

Beginning date (Ma):

354.27

Ending stage:

Tournaisian

Fraction up in the ending stage:

0.5

Ending date (Ma):

353.02

Depositional setting

Depositional pattern:

Additional Information

Compiler:

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