Dzheroy Formation

Dzheroy Fm

Period:

Ordovician

Age Interval:

Middle Ordovician, K5a

Province:
Kyzylkum Region

Type Locality and Naming

Along the Jeroi ravine, N. Tamdytau, Central Kyzylkum. Z.M.Abdazimova et al., 1996. Stratotype in the Jeroi ravine.

Synonym: Dzheroyskaya Suite, Джеройская св.

Lithology and Thickness

Siliceous-argillaceous, jasper-like rocks or phthanites, platy siltstone (aleurolites) of black, green, gray, bluish-gray, dark green color. Thickness 20-120m.

Lithology Pattern:

Chert

Relationships and Distribution

Lower contact

Stratigraphic boundaries are unknown.

Upper contact

Stratigraphic boundaries are unknown.

Regional extent

Central Kyzylkum, locally in the eastern N. Tamdytau. Distinguished from the composition of the Elemesashin Fm (conditionally Middle Carboniferous). Siliceous-terrigenous formations in the form of tectonic blocks, scales extending in strips and boulder horizons from the Jeroi ravine to the Elemesashin ridge. Correlated with the upper part of the Dzhalatar Fm; north Nuratau.

GeoJSON

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Fossils

Contains Middle Ordovician conodonts - Falodus prodentatus (Gr. et Ell.), Protopanderodus cf. insculptus (Br. et Mehl.), Cordylodus cf. spinatus (Had.), Drepanodus subarcuatus Fsrn., D. arcuatus Pand.; radiolarians - Entactina sp., Polyentactiniinae.

Age

Age Span:

Beginning stage:

Dapingian

Fraction up in beginning stage:

0.0

Beginning date (Ma):

471.26

Ending stage:

Dapingian

Fraction up in the ending stage:

1.0

Ending date (Ma):

469.42

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)”