Adyrakou Formation

Adyrakou Fm

Period:

Devonian

Age Interval:

Upper Devonian (upper Frasnian), F10b

Province:
Fergana

Type Locality and Naming

Along the valley of Adyrau, left tributary of the Soh River, Alai Range. V.B. Goryanov, A.D. Miklouho-Maclay et al., 1961 (176, p. 19). In 1976, V.B. Goryanov named it "Sarybelskaya suite" with a clarification of the composition (Bulgaria et al., 1982). It is middle formation in Alay Gr.

Synonym: Adyrakouskaya Suite, Адыракоусская св.

Lithology and Thickness

Limestones with thin layers of marls, dolomitic limestones, dolomites, sandstones, gravelites. Thickness from 300-500 to 1300 m.

Lithology Pattern:

Limestone

Relationships and Distribution

Lower contact

Conformably or with hidden unconformity overlies the Boordin Fm

Upper contact

It is conformably overlain by the Nazarin Fm (460)

Regional extent

Alai Range. Stratotype Along the valley of Adyrau.

GeoJSON

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Fossils

Contains stromatoporoids - Amphipora patokensis Riab., Phillipsastraea cf. filata Schloth., Theodossia anossofi (Vern.) and others, characteristic of the late Frasnian time.

Age

Fossil data provides the characteristic of the late Frasnian time

Age Span:

Beginning stage:

Frasnian

Fraction up in beginning stage:

0.4

Beginning date (Ma):

375.78

Ending stage:

Frasnian

Fraction up in the ending stage:

1.0

Ending date (Ma):

371.10

Depositional setting

Depositional pattern:

Additional Information

Compiler:

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