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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Zoy Formation

Zoy Fm

Period:

Carboniferous

Age Interval:

Lower Visean (C₁ zs), C2, C2a

Province:
Central W Tajik

Type Locality and Naming

Includes in Dushanbe-west Shirkent-Luchob, east Shirkent-Luchob. It was distinguished in 1941.The suite named by E.M. Golovin, proposed by G.S. Chikrizov and K.V. Ryskina in 1948.

Synonym: Zoy suite, 3ойская свита, Zoyan suite, Zoysian Suite

Reference section:

Lithology and Thickness

The Zoy Fm is composed of grey siltstones, quartz sandstones, claystones and clay shales containing interlayers of dacites, liparites and their tuffs, the quantity of which increases towards the top of the section. Thickness is 350-500 m.

The lower part of the Zoy Fm (250-350 m) consists of dark grey and grey siltstones, claystones, and clay shales containing frequent interlayers of quartz sandstones, less often liparitic porphyroids and their tuffs.

The upper part of the suite (100-150 m) is composed of interbedding of greenish-grey, pink dacitic and liparitic porphyroids and their tuffs with beds of siltstones and shales.

Lithology Pattern:

Sandy_claystone

Relationships and Distribution

Lower contact

Within the described area, its contacts are tectonic. In more western regions, the Zoy Fm unconformably overlies the Obizarang Fm of the Vendian - Lower Paleozoic. In places, the Zoyan suite is absent and the Vakhshvar Fm (вахшиварская свита) directly overlies the Obizarang Fm (обизарангской).

Upper contact

It is overlapped with erosion by the Vakhshvar Fm of the Middle Visean - Lower Serpukhovian.

Regional extent

It is widespread in the Dushanbe region.

GeoJSON

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Fossils

In the lower part, in the siltstones on the Akdjar- Shirkent watershed, V.N. Yefimenko, Ye.A. Kosmynin, and K.O. Tsoriev discovered plant remains of Micheevia cf. pulchella Zal., Protolepidodendron aff. arborescens Gze, characteristic of the Tournaisian and Lower Visean deposits.

Age

The Early Visean age of the top of the Zoy Fm is inferred from its practically conformable lying beneath the Vakhshvar Fm (вахшиварской свитой), which contains organic remains of the Middle Visean in its lower part. Tournaisian formations in the Zoy Fm are assumed, since the collected remains of flora (see above) may also be Tournaisian. F. R. Bensh (1969) refers the Zoy Fm to the Lower Visean.

Age Span:

Beginning stage:

Tournaisian

Fraction up in beginning stage:

0.0

Beginning date (Ma):

359.30

Ending stage:

Visean

Fraction up in the ending stage:

0.5

Ending date (Ma):

338.54

Depositional setting

Depositional pattern:

Additional Information

Compiler:

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