Koskuduk Formation

Koskuduk Fm

Period:

Silurian

Age Interval:

Pridoli, K5

Province:
Kyzylkum Region

Type Locality and Naming

Along the Koskuduksay, N. Tamdytau, Central Kyzylkumy. A.I. Kim et al., (1974), in the volume of Pridoli.

Synonym: Koskudukskaya Suite, Коскудукская св.

Lithology and Thickness

Upper part (thickness 20-30m) - flaggy and thick-bedded, organodetrital and crinoidal limestones, interbedded with carbonate, coarse-bedded sandstones, siltstone (aleurolites), gravelites, conglomerates, the latter containing reworked ancient fauna.

Lower part of the suite (thickness 60-80m) - interbedding of thick-bedded, greenish-gray polymictic and yellowish-gray calcareous sandstones with siltstone (aleurolites) and silvery-gray slates.

Lithology Pattern:

Aus Conglomerate

Relationships and Distribution

Lower contact

Stratigraphic contacts are unclear due to the complexity of the tectonics, but biostratigraphic reconstruction of the section allows for the possibility of stratigraphic relationships with Ludlow (Kosbulak Fm) and Lower Devonian (Dzhaksan Fm) deposits.

Upper contact

Regional extent

GeoJSON

null

Fossils

Graptolites of the Tamplograptus formosus zone - Tamplograptus formosus (Bouček), Pseudomonoclimacis ultimus (Perner.), Skalograptus sp.; chitinozoans Urnochitina urna (Eis.), Margachitina catenaria crassipens Paris., Eisenackitina bohemica (Eis.) and others.

Age

The Prídolí age is determined by graptolites of the Tamplograptus formosus zone

Age Span:

Beginning stage:

Pridoli

Fraction up in beginning stage:

0.0

Beginning date (Ma):

422.73

Ending stage:

Pridoli

Fraction up in the ending stage:

1.0

Ending date (Ma):

419.00

Depositional setting

Depositional pattern:

Additional Information

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)”