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

Bakhiltau Formation

Bakhiltau Fm

Period:

Devonian

Age Interval:

Middle Devonian, N8

Province:
Nuratau

Type Locality and Naming

In the Bakhiltay Mountains( Bakhiltau?), Southern Nuratau Range. Yu.V. Shumakov et al. (1973) from the composition of the Aktaw marbles. Upper formation of the Aktau Gr.

Synonym: Bakhiltayuskaya Suite, Бахильтауская св.

Lithology and Thickness

Divided into two sub-suites.

Upper sub-suite (watershed part of the northern slope of the Bahiltayu Mountains, upper reaches of the Charhan River basin) - white massive marbles, sometimes light gray, sugary, coarse-grained, crystalline, with lens-shaped deposits of whetstone-like formations (thickness 0.3-0.5m with an extension of 1-3m). Thickness 350m. At the base of the sub-suite, marbles contain recrystallized corals resembling branching tabulates of Devonian appearance (371).

Lower sub-suite (southern slope of the Bahiltayu Mountains) - white, yellowish-white, gray, dark gray, fine- and indistinctly layered, massive, sugary marbles with interlayers and packets of limestones, sometimes lens-shaped bodies of whetstone-like formations are encountered. Thickness 510m. Contains stromatoporoids - Stachyodes singularis Javor., Amphipora ramosa Phill., A. regularis Less., characteristic of middle Devonian deposits of the Zhivet cliff and other regions.

Total thickness of the suite is 850 m.

Relationships with surrounding strata are tectonic.

Lithology Pattern:

Limestone

Relationships and Distribution

Lower contact

Schematic stratigraphic column indicates the lower contact as Charhansay Fm

Upper contact

Schematic stratigraphic column indicates the upper contact as Aktau Gr

Regional extent

GeoJSON

null

Fossils

Age

Yu.V. Shumakov et al. (1973) conditionally date it to the late Silurian; S.K. Piven et al. (1976) - upper middle Ordovician; I.A. Pyanovskaya et al. (371) - Zhivet; R.S. Khan et al. (1989) consider the separation of the Bahiltau Fm unacceptable and all Aktau Gr marbles are included in the Aktau Gr with an age of Silurian-Carboniferous; V.S. Korsakov et al. (1993) - middle Devonian conditionally; on the State Geological Map-500 of Uzbekistan (460) - middle Devonian, included in the Aktawska series.

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:

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