Azhriktin Formation

Azhriktin Fm

Period:

Carboniferous

Age Interval:

Lower Moscovian, K4, K6

Province:
Kyzylkum Region

Type Locality and Naming

Along A. Azhrikti, Aktau city, Central Kyzylkumy. 3.S. Rumyantseva in 1968 (386, p. 22). Stratotype on the southern slope of Aktau Mountain.

Synonym: Azhrikhtinskaya Formation, Ажриктинская св.

Lithology and Thickness

Claystone (argillites), above - interbedded dark-colored sandstones, siltstone (aleurolites), claystone (argillites_, gravellites, lenticular layers of small-pebble conglomerates. In the upper part - a horizon of sandstones with numerous fragments and boulders of limestones of different ages (Devonian, Lower Carboniferous, possibly Cambrian). Thickness (incomplete) 520m.

Lithology Pattern:

Sandy claystone

Relationships and Distribution

Lower contact

Conformably overlies the Bozdon Fm or Severo-Muruntau Fm (North Murontau Fm)

Upper contact

Upper contact is tectonic. (165; 460).

Regional extent

Central Kyzylkumy, Aktau Mountains, Sangruntau.

GeoJSON

null

Fossils

In carbonaceous claystone (argillites) at the base of the suite, individual brachiopods - Isogramma sp., gastropods - Bucaniopsis calamitoides Grab., Straparollus cf. subquadratus M. et W. In the carbonate cement of graywacke sandstones - recrystallized foraminifers of Middle Carboniferous appearance - Endothyra sp., Eostaffella sp., Ozawainella sp., Profusulinella sp., Paleotextularia sp.

Age

Age Span:

Beginning stage:

Moscovian

Fraction up in beginning stage:

0.2

Beginning date (Ma):

313.52

Ending stage:

Moscovian

Fraction up in the ending stage:

0.4

Ending date (Ma):

311.90

Depositional setting

Depositional pattern:

Additional Information

Compiler:

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