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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Kozyndyn Formation

Kozyndyn Fm

Period:

Ordovician

Age Interval:

Tremadocian – Hirnantian (O), V1

Province:
SE Tajik (Central W Pamir)

Type Locality and Naming

It was delineated by V. I. Dronov et al. (1960).

Synonym: Kozindayskaya suite, козындыйская свита, Kozinday Fm, Kozindai

Reference section:

Lithology and Thickness

The Kozyndyn Fm is represented by an uneven interbedding of dark gray, green, and purple clayey, carbonaceous, and calcareous shales with a total thickness of 800 m.

Lithology Pattern:

Claystone

Relationships and Distribution

Lower contact

In the layers, transitional to the Zorabat Fm of the Cambrian? (40-50 m), light and purple limestone interbeds and dense purple tuffs and tuffolav are noted.

Upper contact

The transition to the overlying limestones of the Lower Silurian is gradual. The schematic stratigraphic column indicates Lower Vnach Outcrops Fm

Regional extent

It is spread in the Central Pamir in the Vanch and Muzkol ranges.

GeoJSON

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Fossils

The base of the suite (The layers transitional, attributed by V.I. Dronov and S.S. Kara petov to the Zorabat Fm, are characterized by trilobites of the Tremadocian and Hirnantian stages: Dikelokephalina cf. dicraeura Angelin, Apatokephalus cf. serratus Sars. et Bolck. var. Dubius Moberg, Nileus sp. The higher horizons of the suite contain remains of Middle Ordovician trilobites Dulanaspis cf. levis Bal., Dionide pamirica Bal., Cyclopyge pamirica Bal., Trinucleus pamiricus Bal., Pseudobasilicus nobilis pamiricus Bal. In the very top, remains of graptolites Dyctionema aff. opiki Obut et Rytzk have been collected, which have an Upper Ordovician appearance and allow us to suppose the presence of Ashgillian formations here.

Age

The Tremadocian – Hirnantian age of the suite is substantiated by a complex of organic remains collected throughout the section (Dronov et al., 1960; Karaev, 1963a).

Age Span:

Beginning stage:

Tremadocian

Fraction up in beginning stage:

0.0

Beginning date (Ma):

486.85

Ending stage:

Hirnantian

Fraction up in the ending stage:

1.0

Ending date (Ma):

443.07

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.