Cenozoic

Cretaceous

Jurassic

Triassic

Permian

Carboniferous

Devonian

Silurian

Ordovician

Cambrian

Neoproterozoic

Main source = Baratov, R.B., et al. (1976). Subdivisions of stratified and intrusive rocks of Tajikistan. Publishing House "Donish", Dushanbe, 269 pp. plus tables. Provided by Dr. Jovid Aminov, Nazarbayev University, Astana, Kazakhstan Translated to English by the GeoGPT group, Zhejiang Lab, Hangzhou, China--see About

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Baykungur Formation

Baykungur Fm

Period:

Silurian

Age Interval:

Early Llandovery (S₁ ln₁₊₂), S4

Province:
North Tajik

Type Locality and Naming

The Baykungur Fm was distinguished by M. M. Posokhova in 1956 in the western part of the Turkestan range.

Synonym: lower and middle subseries, Baykungurskaya suite, байкунгурская свитa, Lyangarskaya and Kshatdakskaya, лянгарскую и кштудакскую (in the Zeravshan valley, divided by A.S. Shadchinev (1970)

Reference section:

Lithology and Thickness

The considered suite forms the lower part of a powerful graptolite formation. It consists of dark gray clayey and carbonaceous clayey slates, containing interlayers of feldspar-quartz sandstones and rarely limestones and jasper. Its incomplete thickness is 1500 m.

Lithology Pattern:

Clayey sandstone

Relationships and Distribution

Lower contact

The base of the suite is not exposed.

Upper contact

It is overlain conformably by the Khushikat Fm, хушикатской ситой.

Regional extent

It is widespread in the Turkestan region. In its southern part, on the southern slopes of the Turkestan range.

GeoJSON

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Fossils

Graptolite remains are found throughout the section of the Baykungur Fm. Its lower part is characterized by early Llandovery forms: Akidograptus ascensus Davies, Cystograptus vesiculosus Nich., Diplograptus modestus Lapw., Pristiograptus cyphus Lapw.; the upper part is characterized by middle Llandovery forms: Pristiograptus gregarius Lapw., Demirastrites convolutus His., Monograptus sedwicki Portl.

Age

Lower- Middle Llandovery

Age Span:

Beginning stage:

Rhuddanian

Fraction up in beginning stage:

0.0

Beginning date (Ma):

443.07

Ending stage:

Aeronian

Fraction up in the ending stage:

1.0

Ending date (Ma):

438.59

Depositional setting

Depositional pattern:

Additional Information

Compiler:

Extracted from Baratov, R. B. (1976). Subdivisions of stratified and intrusive rocks of Tajikistan. Donish, Dushanbe, 276.