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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Rangkul Formation

Rangkul Fm

Period:

Triassic

Age Interval:

Induan—Carnian (T_1-3rn), Ak-Ra1

Province:
East Tajik (NE Pamir)

Type Locality and Naming

Includes in Akbaital-Rangkul region. It was identified in 1937 by P.D. Vinogradov.

Synonym:

Reference section:

Lithology and Thickness

It is composed of massive and coarsely bedded reef limestones up to 500-800 m thick, lying in a tectonic schist.

Lithology Pattern:

Reef limestone

Relationships and Distribution

Lower contact

Upper contact

Overlain by the Jankaindin Fm.

Regional extent

It is widespread in the Central Pamir, in the zone of the southern Rangkul tectonic schists.

GeoJSON

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Fossils

Organic remains have mostly been collected in debris and are not strictly tied to the section. Among them, Early Triassic-Anisian pelecypods Myophoria cf. laevigata Zieth., Eumorphotis cf. venetiana (Hauer); Anisian ammonoids Monophyl] lites cf. sphaerophyllus (Hauer), Leiophyllites aff. pitamaha Dien.; brachiopods Tetractinella cf. trigonella Schloth., Spiriferina cf. fragilis Schloth.; Ladinian-Carnian and Carnian pelecypods Aviculopecten cf. wissmani Münst., Lima cf. subpunctata Orb., Amonotis sp.

Age

The listed forms allow considering the age of the Rangkul suite within the Induan-Carnian stages (Kushlin, 1973). Jankaindin Fm above is “Carnian-Rhaetian”; therefore top put as mid-Carnian for display purposes.

Age Span:

Beginning stage:

Induan

Fraction up in beginning stage:

0.0

Beginning date (Ma):

251.90

Ending stage:

Carnian

Fraction up in the ending stage:

0.5

Ending date (Ma):

232.15

Depositional setting

Depositional pattern:

Additional Information

Compiler:

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