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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Mamasair Formation

Mamasair Fm

Period:

Jurassic

Age Interval:

Bajocian (J t-bj), Sar3

Province:
East Tajik (easternmost Pamir)

Type Locality and Naming

Includes in Sarykoln district (Istyk type section (Kunteisk and Kokchagin areas)

Synonym: Mamasair suite, Мамазаирская свита

Reference section:

Lithology and Thickness

It is composed of gray, thick-bedded limestones with rare interlayers of calcareous shales and marls. (50-70 m)

Lithology Pattern:

Clayey limestone

Relationships and Distribution

Lower contact

Schematic stratigraphic column indicates the lower contact as Karauldyn Fm

Upper contact

Regional extent

It is widespread in the basins of the rivers Irkaltdzhilga, Korteke, Shahtesay, Mamazair. It is distinguished everywhere at the base of the limestone part of the Toarcian-Bajocian strata section.

GeoJSON

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Fossils

Organic remains are mainly represented by Bajocian pelecypods Modiolus scalatus Waag., Goniomya literata Sow., Homomya obtusa Agass., Ceratomya aff. bucharica Boriss.; and corals Pseudocoenia conifera (M. Edw. et Haime), Thamnasteria lye1 li M. Edw. et Haime.

Age

Fossil data indicates it is Bajocian.

Age Span:

Beginning stage:

Bajocian

Fraction up in beginning stage:

0.0

Beginning date (Ma):

170.90

Ending stage:

Bajocian

Fraction up in the ending stage:

0.5

Ending date (Ma):

169.54

Depositional setting

Depositional pattern:

Additional Information

Compiler:

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