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

Asmansay Formation

Asmansay Fm

Period:

Devonian

Age Interval:

Lower Devonian, N4

Province:
Nuratau

Type Locality and Naming

Along the Asman stream, N. Nuratau Ridge. I.A. Kim, V.P. Vashchenkov 1986 (1987f.). Hypostratotype on the southern slope of the central part of Balyklytau.

Synonym: Asmansayskaya Suite, Асмансайская св.

Lithology and Thickness

Limestones from thin-bedded to massive light and dark gray with rare dolomite layers. Thickness more than 500m.

Lithology Pattern:

Limestone

Relationships and Distribution

Lower contact

Lower boundary by a fault with basalts of the Shavaz Fm and dolomites with cherts of the Bogambir Fm (Bozaygyr Fm).

Upper contact

Overlain with unclear relationships by the Egarkelitau Fm.

Regional extent

North Nuratau Range, southern slopes of Egarbelitau, Bozaygyr, southern slope of the central part of Balyklytau.

GeoJSON

null

Fossils

In limestones, conodonts - Ozarkodina stygia (Flajs.), Pandorinella steinhornensis miae (Bultynok), P. steinhornensis postoptima Bard., Polygnathus dehiscens Phil. et Jach., P. perbonus (Phil.) and others; brachiopods - Parachonetes vernenili Barr., Carinatina amiraspa (Eichw.), Plescarinatina mala (Khod.) and others; tabulates - Pachyfavosites sp. (ex gr. cylindricus) Janet., Squamefavosites ex gr. nikiforovae (Chekhov.) and others; stromatoporoids - Parallelostroma sp., Stachyodes sp. and others, characterizing Lochkovian and Pragian deposits.

Age

Considering the complex tectonic structure of the carbonate ridges of Egarkelitau, Bozaygyr, and Balyklytau, the absence of a complete section, and the presence of Lochkovian organic remains in scattered points, the age of the Asmansay Fm is accepted in full as Lower Devonian. I.A. Kim and V.P. Vashchenko (1987), V.S. Korsakov et al. (1993) attributed the Asmansay Fm to Upper Silurian-Lower Devonian, including scattered outcrops of carbonate rocks and Upper Silurian. On the State Geol Map-500 of Uzbekistan (460) - Lower Devonian.Put as Base Eifelian for graphic purposes (due to ages assigned to unerlying unis) - "age accepted as Lower Devonian

Age Span:

Beginning stage:

Eifelian

Fraction up in beginning stage:

0.0

Beginning date (Ma):

394.30

Ending stage:

Eifelian

Fraction up in the ending stage:

1.0

Ending date (Ma):

385.30

Depositional setting

Depositional pattern:

Additional Information

Compiler:

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