Karadiirmen Formation

Karadiirmen Fm

Period:

Jurassic

Age Interval:

Upper Aalenian-Lower Bajocian, U4

Province:
Ustyurt-Sultanuzdag

Type Locality and Naming

Along Karadiirman Mountain, northern slope of the V. Karatau ridge, Mangyshlak Peninsula. R.I. Vyalova in 1960 (163, p.242). Previously, these deposits were subdivided (from bottom to top) into the ash-gray, coal-bearing suite, and the interbedded suite. A.A. Saveliev and A.K. Kalugin (394) limited the age span of the Karadiirman Fm(232). A.K. Kalugin, N.V. Beznosov. Stratigraphic section (446). On South Ustyurt, Along the Samarkand conference (383, table 4, p.2), the undifferentiated upper Tonaishin Fm sub-suite and the Karadiirmen Fm were identified, which were renamed the Berdak Fm.

Synonym: Karadiirmen Suite, Карадирменская св.

Lithology and Thickness

Alternation of clays, silty (aleuritic) and carbonaceous clays, sandstones, less frequently sands and coals. In the lower part, sandstones with inclusions of white quartz pebbles, locally transitioning into a thin layer of conglomerate. Thickness 150-180m.

Lithology Pattern:

Claystone

Relationships and Distribution

Lower contact

Overlies transgressively the Paleozoic, Tonaishin Fm or various horizons of the Kokalyin Fm.

Upper contact

Overlain transgressively by the Bazarylin Fm

Regional extent

GeoJSON

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Fossils

Contains large plant remains - Coniopteris angustiloba Brick and others; freshwater bivalve mollusks - Ferganoconcha tschernyschowi Kol., Pseudocardina asiatica Tschern. and others.

Age

A.K. Kalugin, N.V. Beznosov (446) assign the K. suite to the lower Bajocian.

Age Span:

Beginning stage:

Aalenian

Fraction up in beginning stage:

0.65

Beginning date (Ma):

172.23

Ending stage:

Bajocian

Fraction up in the ending stage:

0.2

Ending date (Ma):

170.35

Depositional setting

Depositional pattern:

Additional Information

Compiler:

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