Neogene

Paleogene

Cretaceous

Jurassic

Triassic

Permian

Carboniferous

Devonian

Silurian

Ordovician

Cambrian

Neoproterozoic

Mesoproterozoic

Paleoproterozoic

Main source = Abduazimova, Z.M. (Ed.), 2001. Stratigraphic Dictionary of Uzbekistan. IMR (Institute of Mineral Resources), Tashkent, 580 pp. (In Russian) Translated to English by the GeoGPT group, Zhejiang Lab, Hangzhou, China--see About

Akchapkan Formation

Akchapkan Fm

Period:

Ordovician

Age Interval:

Tremadocian, N5

Province:
Nuratau

Type Locality and Naming

Along the Aktchapkan River, Turkestan Mountains. A.N. Golikov in 1985 (1988), in the volume of the Tremadoc (460, p.60). Stratotype along the Akchapsai River.

Synonym: Akchapkan Suite, Акчанканская св.

Lithology and Thickness

According to A., dark gray, grayish-green polymictic siltstone (aleurolites) with interlayers of argillites and siliceous shales, less frequently limestones. Thickness 750m (?).

Lithology Pattern:

Siltstone

Relationships and Distribution

Lower contact

Tectonic contacts. According to A.N. Golikov, it is conformable with the underlying Rabutian Fm

Upper contact

Tectonic contacts. According to A.N. Golikov, it is conformable with the overlying Almalykian Fm (460).

Regional extent

North slope of the Turkestan Range, Chumkartau Mts., Akchapsai River; Zamin Basin; Malguzar Mts.

GeoJSON

null

Fossils

Contains Tremadocian graptolites - Kiaerograptus antiquus (Hall.), Clonograptus tenellus (Linn.), Dictyonema flabelleforma intermedium Prantl. et Přibyl. and others (165).

Age

Age Span:

Beginning stage:

Tremadocian

Fraction up in beginning stage:

0.0

Beginning date (Ma):

486.85

Ending stage:

Tremadocian

Fraction up in the ending stage:

1.0

Ending date (Ma):

477.08

Depositional setting

Depositional pattern:

Additional Information

The span and thickness of the suite require revision.

Compiler:

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