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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Ravash Formation

Ravash Fm

Period:

Permian

Age Interval:

Upper Permian (P2? Rv), S1

Province:
North Tajik

Type Locality and Naming

It was identified by N.P. Vasilyevsky (1952).

Synonym: Murgab Horizon, Ravash suite, Rovash Suite, Rovashskaya suite, Равашская свита

Reference section:

Lithology and Thickness

Lava. Composed of dark gray or greenish-gray trachybasalts of a lava-like appearance, at the base of which there are tuff conglomerates, tuff sandstones, and tuffs of pyroxene trachybasalts. Thickness is 400-800 m. It is conditionally attributed to the Murgab horizon based on its position in the section.

Lithology Pattern:

Lava

Relationships and Distribution

Lower contact

Lies with slight erosion on the volcanics of the lower Permian Shurabsay Fm (шурабсайской свиты)

Upper contact

It is covered with erosion by volcanic rocks of the Kyzylkuren Fm (кызылнуринской свиты)

Regional extent

Predominantly distributed in the Karamazar region, mainly in the Tashkessen depression.

GeoJSON

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Fossils

Organic remains in the Ravash suite (равашской Свите) were not found.

Age

It is mentioned that in the Karamazar district, a more ancient faunistically characterized Lower Permian Shurabsay suite (шурабсайская свита) is known, overridden with erosion by the Ravash suite (равашакой свитой), which discordantly underlies the Kyzyl-Nurinsky and is conditionally attributed to the lower levels of the Upper Permian (Murgab horizon). Hence represented in Upper Permian for schematic stratigraphic column.

Age Span:

Beginning stage:

Wuchiapingian

Fraction up in beginning stage:

0.0

Beginning date (Ma):

259.55

Ending stage:

Wuchiapingian

Fraction up in the ending stage:

1.0

Ending date (Ma):

254.24

Depositional setting

Depositional pattern:

Additional Information

V.N. Baykov, V.V. Mikhailov, and V.A. Moskvitsev believe that the overwhelming majority of formations described as the Ravash "suite" (which is done in this work) represent extrusive rocks of a large paleovolcano of the fissure type, encompassing the Tashkessen depression in a semicircle.

Compiler:

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