Nadak Formation

Nadak Fm

Period:

Carboniferous

Age Interval:

Moscovian-Upper Carboniferous, CK8, CK9

Province:
Chatkal-Kuramin Region

Type Locality and Naming

Along the river Nadak, Kuramin Ridge. Z. P. Artemova in 1956 (411, p. 27). The stratotype is in the upper reaches of the Nadak River.

Synonym: Nadakskaya Suite, Надакская св.

Lithology and Thickness

At the base, there is a basal package (up to 350 m thickness) of conglomerates, sandstones, and siltstone (aleurolites) with rare layers of bituminous and siliceous limestones; above this, alternating conglomerates, sandstones, siltstone (aleurolites), tuffs, and ignimbrites of dacitic and andesidacitic composition, andesidacitic lavas, and less frequently andesites. The facies composition of the suite is characterized by extrusive domes. The thickness of the suite is 400-2500m.

Lithology Pattern:

Aus Conglomerate

Relationships and Distribution

Lower contact

Upper contact

Regional extent

Kuramin and Chatkal Suites in the Kuramin region within the Lashkerek, Adrasman, and Kyzylnurin volcano-structures and the eastern part of the Shavaz-Dukent graben.

GeoJSON

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Fossils

In the lower part, plants that allow dating the age of the enclosing rocks to the Moscovian stage are found: Lepidodendron ex gr. worthenii Lesq., Neuropteris heterophylla Bron., Kandyria vasilkovskyi (Sixt.), Aulacotheca kandyrica Sav.; spores and pollen Leiotriletes inermis (Wal.), Lophotriletes verrucosus (Jbr.), Acanthotriletes hirtus Isch., Brachytrilistrium patullum Isch., Monoptycha (Ginkgo) cycadoformis Naum.; in the upper part, plants such as Sphenophyllum ex gr. majus (Bronn.), Sphenopteris marchalii Stock. et Math., Karabaupteris angrenica Sav., Gissarella kuramensis Sav., Cordaites schenkii Halle, Samaropsis czatkalensis Sav., Lebachia piniformis (Schloth.)

Age

In the lower part, plants that allow dating the age of the enclosing rocks to the Moscovian stage. In the upper part, plants indicate the Gzhelian age of the rocks.

Age Span:

Beginning stage:

Moscovian

Fraction up in beginning stage:

0.9

Beginning date (Ma):

307.83

Ending stage:

Gzhelian

Fraction up in the ending stage:

1.0

Ending date (Ma):

298.89

Depositional setting

Depositional pattern:

Additional Information

Compiler:

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