Shuruk-Ord Formation

Shuruk-Ord Fm

Period:

Ordovician

Age Interval:

Ashgillian, K9

Province:
Kyzylkum Region

Type Locality and Naming

Along the Shuruk quarry, Kuldjuktau Mountains, Central Kyzylkum. Ya. B. Aysanov et al., 1984. Previously these deposits were attributed by Ya.B. Aysanov (44), A.K. Bukharin et al. (122) to the second type of the Oydybulak Fm.

Synonym: Shuruk Suite, Шурукская св.

Lithology and Thickness

According to A.A.: Upper part (up to 130-150 m) various-grained dark gray sandstones and clayey slates with lenses of conglomerates, gravelites, and volcanogenic rocks (rhyolites, andesites, basalts, and their tuffs). Lower part (up to 70-100 m) carbonate gray and dark gray sandstones with lenses of layered bituminous limestones and black siliceous rocks.

Total up to 200-250 m.

Lithology Pattern:

Clayey sandstone

Relationships and Distribution

Lower contact

The lower boundary is unknown

Upper contact

Overlain with a gradual transition by terrigenous rocks of the Darbazin Fm (460).

Regional extent

Central Kyzylkum, southern slope of the Kuldjuktau Mountains, Kynkyrtay, northeastern quarry of Uchkuduk, southwestern end of the Tozbulak intrusion. Correlated with the upper part of the Kazakasuy Fm.

GeoJSON

null

Fossils

Contains tabulates of the Upper Ordovician Lyopora regularis Kim, Palaeofavosites schmidti Sok., P. cf. globosus Sok., P. abstrusus Klaam. and others (44).

Age

Upper Ordovician (Ashgillian)

Age Span:

Beginning stage:

Katian

Fraction up in beginning stage:

0.5

Beginning date (Ma):

448.98

Ending stage:

Hirnantian

Fraction up in the ending stage:

1.0

Ending date (Ma):

443.07

Depositional setting

Depositional pattern:

Additional Information

Compiler:

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