Okuzbulak Gr

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

Okuzbulak Gr

Period:

Cretaceous

Age Interval:

upper Barremian - lower Aptian, B1-B3

Province:
Bukhara-SW Gissar

Type Locality and Naming

Along the Oquzbulak and Kishlak formations, South-West Gissar. N.P. Kheraskov, 1934 (487, p.19).

Synonym: Okuzbulakskaya Formation, Окузбулакская св.

Lithology and Thickness

X.X. Mirzakamalov et al. (51) translated the formation to the rank of a series, distinguishing three formations within it: upward succession of the Machay Fm, Kundalyangtau Fm, and Lyalyimkan Fm. (55; 63; 115; 133; 167; 274; 445; 452).

Lower part (Machay Fm) - siltstone (aleurolites), clays, reddish-brown sandstones with gypsum interlayers (10-50 m)

Middle (Kundalyantau Fm) - marls, clays, gray sandstones with interlayers of shell limestones (30-70 m)

Upper (Lyalimkan Fm) - clays, siltstone (aleurolites), red sandstones with interlayers of limestones, gypsum, and gravelites (25-70m).

Lithology Pattern:

Siltstone

Relationships and Distribution

Lower contact

The formation lies conformably on the Kyzyltash Fm and transgressively on the Paleozoic (North Central Gissar)

Upper contact

It is overlain with erosion by the Kaligrek Fm, Aksuisky Fm, and Gelandaryn Fm.

Regional extent

South-West, South, Central, North-West Gissar, Babatag ridge, Bukhara-Karshinsky region wells.

GeoJSON

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Fossils

Contains in the Lower part foraminifera - Qinqueloculina micra complanata (S. Mam.), Trocholina ex gr. burlini Gorb. and a complex of spores and pollen.

In the Middle - ammonites - Deshayesites cf. antiquas Bogd.; marine bivalve mollusks - Lopha multicostata Mirk., Exogyra trigonalis Mirk., Ceratostreon vinokurovae Mirk., Pseudogyra pennata Mirk.; foraminifera - Milliammina mjatliukae Dain, Gyroidinoides sokolovae Mjatl. and a complex of spores and pollen.

In the Upper - foraminifera - Milliammina kuznetzovae S. Mam.; ostracods - Antepaijenborchella praealta turkmenica Andrv., Malzevia malzi Andrv. and a complex of spores and pollen.

Age

It belongs to the upper Barremian - lower Aptian; in the Stratigraphic Lexicon (446) - to the Barremian - lower Aptian or Barremian.

Age Span:

Beginning stage:

Barremian

Fraction up in beginning stage:

0.5

Beginning date (Ma):

123.95

Ending stage:

Aptian

Fraction up in the ending stage:

0.2

Ending date (Ma):

119.76

Depositional setting

Depositional pattern:

Additional Information

Compiler:

I.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)”