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

Bogambir Formation

Bogambir Fm

Period:

Proterozoic

Age Interval:

Upper Riphean, N6

Province:
Nuratau

Type Locality and Naming

Along Mt. Bogambir, N. Nuratau Ridge. P.N. Podkopaev et al. in 1964, named Bogambir (1964f.), assigned to Wenlock-Ludlow. Stratotype on Mt. Bogambir.

Synonym: Bogambirskaya Suite, Богамбирская св.

Lithology and Thickness

The Bogambir is composed of a series of tectonic scales, thrust over each other, complicated by subvertical faults. The restored section of the suite, based on litho-biofacies studies, is represented in the Lower part by thick to medium-bedded massive gray, dark gray dolomites with numerous biostromes of nevlandiids and kamaziids, interbedded with thin layers of dark brown siliceous-carbonate rock. The Upper part of the section is composed of gray layered oncolite-containing organogenic-detrital dolomites, interbedded with layers of carbonate rocks containing kamaziids, nevlandiids, etc. Thickness up to 225 m.

Lithology Pattern:

Dolomitic limestone

Relationships and Distribution

Lower contact

Contacts are everywhere tectonic.

Upper contact

Contacts are everywhere tectonic.

Regional extent

Northern Nuratau Ridge in the tectonic blocks of the Bogambir Ridge and extends in the form of narrow ridges from it to the Ustahan basin, as well as in the form of small tectonic bodies in melange zones. It is correlated with the Akkuduk suite, and the upper part of the Kokpatass Fm.

GeoJSON

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Fossils

The Late Riphean age is substantiated by a diverse complex belonging to acritarchs - Leiosphaeridia jacutica (Tim.), L. holtedahlii (Tim.), Chuaria">Chuaria">Chuaria">Chuaria circularis Wal., Margominuscula rugosa Naum., Satka elongata Jank. and others; filamentous microfossils - Tortunema sibirica Herm., Eomycetopsis typicus (Herm.), Polytrichoides lineatus Herm., Palaeolyngbya catenata Herm.; microphytolites - Osagia tenuilamellata Reitl., O. columnata Reitl., O. alveolata Schip. (ms), O. corticosa Nar., Volvatella zonalis Nar., Ambigolamellatus horridus Z. Zhur. and others; nevlandiids - Clatristroma cf. tarnovskii Posp., Cl. sp., Aloeolia clathrata Sosn.; kamaziids - Caryschia sp.; stromatolites Frutexina rubia Raab.

Age

Initially, all siliceous-carbonate rocks composing the Bogambir Ridge were attributed to the Bogambir Fm, and based on finds in two localities of corals and brachiopods, its age was dated to the Wenlock. However, studies by G.S. Porshnyakov et al. (357), A.V. Klyushkin (233) have proven that the Bogambir Ridge represents a tectonic package of complex structure with a predominance of imbricate-thrust structures, consisting of tectonic plates or lenses, composed of deposits of different ages and genetic types of the Upper Riphean (Bogambir suite), Vendian(?)-Cambrian (Koybulak suite), Ordovician (Kurbanazin suite), Silurian (Yatakskaya suite), Upper Devonian-Lower Carboniferous (Z.M. Abdazimova et al., 1998f.). A.K. Bukharin, T.N. Novikova et al. (332) include in the composition of the Bogambir Fm a large part of the siliceous-carbonate rocks of the ridge and refer it to the Silurian-Wenlock-Ludlow. I.A. Pyanova et al. (372) distinguish three horizons in its composition: Lower Silurian (Wenlock), conditionally Lower Cambrian, and Middle-Upper Cambrian with tectonic relationships. V.S. Korsakov and N.R. Asatullaev (237) refer a large part of the siliceous-carbonate deposits of the Bogambir Ridge to the Proterozoic, combining them into the Bogambir Fm; the remaining part - to the Yatak Fm of the Lower Silurian. In the monograph (165) and on the State Geological Map-500 of Uzbekistan (460), the Bogambir Fm is given in a revised volume (16; 17; Abdazimova et al., 1993f., 1996f., 1998f.) and is assigned to the Upper Riphean.

Age Span:

Beginning stage:

Tonian

Fraction up in beginning stage:

0.0

Beginning date (Ma):

1,000.00

Ending stage:

Cryogenian

Fraction up in the ending stage:

1.0

Ending date (Ma):

635.00

Depositional setting

Depositional pattern:

Additional Information

Compiler:

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