Neogene

Paleogene

Cretaceous

Jurassic

Triassic

Permian

Carboniferous

Devonian

Silurian

Ordovician

Cambrian

Neoproterozoic

Mesoproterozoic

Paleoproterozoic

Main source = Abduazimova, Z.M. (Ed.), 2001. Stratigraphic Dictionary of Uzbekistan. IMR (Institute of Mineral Resources), Tashkent, 580 pp. (In Russian) Translated to English by the GeoGPT group, Zhejiang Lab, Hangzhou, China--see About

Yarmanchin Formation

Yarmanchin Fm

Period:

Silurian

Age Interval:

Llandovery, Z5

Province:
Zarafshan-N.Gissar

Type Locality and Naming

By the Yarmanchay River, southeastern Zirabulak Mountains. V.S. Korsakov et al., 1962. Stratotype east of the village of Altyaul. Previously, the deposits were attributed to the "transitional horizon" from terrigenous Ordovician to carbonate Silurian deposits within the Daraitut suite.

Synonym: Yarmanchinskaya Suite, Ярманчинская св.

Lithology and Thickness

Slates, argillites, siltstone (aleurolites), interbedded with sandstones, gravelites, and limestones. Thickness 140m.

Lithology Pattern:

Claystone

Relationships and Distribution

Lower contact

Lies conformably with a gradual transition on the Altyaul Fm

Upper contact

It is overlain conformably by the Ovkhanin Fm.

Regional extent

Traced as a strip in the Zirabulak Mountains, basin of the Altyaul River, small outcrops near the village of Kurgancha, along the Terikbaba, Yarmanchi, and Turuta rivers.

GeoJSON

null

Fossils

Contains corals - Palaeofavosites cf. alveolaris karinusis Sok., Catenipora sp. ind. and others; stromatoporoids - Clathrodictyon">Clathrodictyon sp. (Barkovskaya et al., 1965, 88).

Age

Lower Silurian (Llandovery stage).

Age Span:

Beginning stage:

Rhuddanian

Fraction up in beginning stage:

0.0

Beginning date (Ma):

443.07

Ending stage:

Telychian

Fraction up in the ending stage:

1.0

Ending date (Ma):

432.93

Depositional setting

Depositional pattern:

Additional Information

Compiler:

V.S.Korsakov – In: GeoGPT translation of: “Abduazimova, Z.M. (Ed.), 2001. Stratigraphic Dictionary of Uzbekistan. IMR (Institute of Mineral Resources), Tashkent, 580 pp. (In Russian)”