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

Azkamar Formation

Azkamar Fm

Period:

Cretaceous

Age Interval:

upper Aptian - lower Albian, Z5

Province:
Zarafshan-N.Gissar

Type Locality and Naming

Along Azkamar, Western Uzbekistan. N.A. Bilalov, 1938 (111, p.20). Stratotype not specified. Parastratotype described in the Auzikarasa Valley.

Synonym: Azkamar Formation, Азкамарская св.

Lithology and Thickness

In the upper part, composed of dark gray, variegated silty (aleurolitic) clays. Thickness 32m.

In the lower part of the suite, represented by light gray, yellow fine-grained sandstones with interlayers of gravelites and variegated siltstone (aleurolites). Thickness 30m.

I.S. Suleimanov in well sections identified three sub-suites in the suite.

Upper sub-suite - dark gray clays, at the base gravelite with phosphorite pebbles. Thickness 10-35m.

Middle sub-suite - dark gray clays with interlayers of siltstone (aleurolites) and shell rocks. Thickness 15-60m.

Lower sub-suite - gray conglomerates, gravelites, sandstones with interlayers of clays. Thickness 10-25m.

Lithology Pattern:

Clayey sandstone

Relationships and Distribution

Lower contact

The suite with erosion overlies the Sardobin Fm and transgressively overlies the Paleozoic.

Upper contact

Conformably overlain by the Karaiz Fm.

Regional extent

The Zirabulak-Ziaetdin Mountains, Karasu; in the adjacent plains, well exposed. A.nolani zone is correlated with the upper part of the Tuzkoy Fm of Central Kyzylkum. H. Jasovi zone, correlated with the Kalaatin Fm (Kalaat Fm) of Central Kyzylkum. The suite is correlated with the lower part of the Jamanyar Fm of Central Kyzylkum.

GeoJSON

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Fossils

Upper sub-suite – Contains foraminifera - Evolutinella asiatica (Zhuk.), E. subevoluta Nikit. et Mjatl., Gaudryinopsis gissarensis (Zhuk.), G. karaisensis (Suleim.).

Middle sub-suite – Contains ammonites - Nuraacanthoplites elegans Frit., marine bivalve mollusks - Linotrigonia gissarensis Vinok.; foraminifera - Verneuilina vinokurovae Zhuk.

Lower sub-suite – Contains marine bivalve mollusks - Liostrea leymerri Dech., Amphidonte arduennensis zeravschanica Muzaph.; brachiopods - Eudesia tekedgikenica Sm.

Age

Upper sub-suite – Belongs to the lower Albian. Lower sub-suite – Belongs to the upper Aptian, A.nolani zone. Belongs to the upper Aptian - H. Jasovi zone. Assigned to the upper Aptian - lower Albian; in Strat. Sl. (446) - to the upper Aptian; Along O.S. Vyalov (158), to the lower Albian; Along I.S. Suleimanov (464), to the Aptian - Albian (313; 445)

Age Span:

Beginning stage:

Aptian

Fraction up in beginning stage:

0.7

Beginning date (Ma):

115.66

Ending stage:

Albian

Fraction up in the ending stage:

0.25

Ending date (Ma):

110.03

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)”