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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Baysun Formation

Baysun Fm

Period:

Jurassic

Age Interval:

Late Bathonian - Early Kimmeridgian (J₁₊₂), C2

Province:
Central W Tajik

Type Locality and Naming

(Gubin, 1937; Resolutions..., 1959)

Synonym: Baysunskaya suite, Байсунская свита

Reference section:

Lithology and Thickness

It is composed of interbedding of claystones, sandstones with layers of marls, oolitic limestones, and shell limestone. 5-22 m thick.

Lithology Pattern:

Sandy limestone

Relationships and Distribution

Lower contact

It lies conformably on the Gurud Fm

Upper contact

It conformably overlies Kugitang Fm

Regional extent

It is developed in the South-Gissar and Dushanbe districts, are combined into the Baysun Fm (гурудскую Свиты) (Gubin, 1937; Resolutions..., 1959).

GeoJSON

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Fossils

In the considered suite, Bathonian-Kimmeridgian cephalopods Meleagrinella echinata Smith., Protocardia concinna (Buch.), Inoperna perplicata (Etall.), and others have been found.

Age

The age of the Baysun Fm on the southern slope of the Gissar Range is Late Bathonian - Early Kimmeridgian, as follows from the given determinations and position in the section. In the compiled legend, new data on the age of the suite are not taken into account. Although, mentioned it spans up to Kimmeridgian, it is taken as Late Bathonian due to ambiguity with agespan.

Age Span:

Beginning stage:

Bathonian

Fraction up in beginning stage:

0.5

Beginning date (Ma):

166.73

Ending stage:

Bathonian

Fraction up in the ending stage:

1.0

Ending date (Ma):

165.29

Depositional setting

In the strike direction (eastward), carbonate...Marine deposits are being replaced by continental sediments.

Depositional pattern:

Additional Information

Compiler:

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