Beshtobin Formation

Beshtobin Fm

Period:

Cretaceous

Age Interval:

Upper Cenomanian- Middle Turonian, U5

Province:
Ustyurt-Sultanuzdag

Type Locality and Naming

Along the Beshtyube Ridge, Southern Pre-Aral region. S.S. Shul'ts (Jr.), 1967, (509, p.15). Exposed by wells. Stratotype in the Besh-Tyube Ridge area.

Synonym: Beshtyubish Formation, Бештобинская св, Beshchubin Fm

Lithology and Thickness

Deltaic, cross-bedded sands, sandstones, conglomerates, and coastal-marine shell limestones, clays, sandstones. Divided into two sub-suites. Lower - conglomerates, sandstones, sands. Thickness 10-100m. Upper - sands, sandstones, clays with loaf-shaped sandy concretions, oyster beds. Thickness 40-94m.

Lithology Pattern:

Sandstone

Relationships and Distribution

Lower contact

Lies conformably, sometimes with erosion on the Khodzhakul-Cret Fm (Hodzhakul suite),

Upper contact

It is transgressively overlain by the Paleogene.

Regional extent

Sultanuizdag Ridge, Besh-Tyube, Kokcha, and adjacent areas of North Central Kyzylkum.

GeoJSON

null

Fossils

Contains in the lower sub-suite ammonites - Metoicoceras sp.; marine bivalve mollusks - Exogyra olisiponensis Sharpe, Quadratotrigonia romanowskii (Arkh.), Asiatotrigonia sultanuisi kuleschi (Vinok.), Pterotrigonia chivensis (Arkh.) and others; in the upper sub-suite ammonites - Watinoceras coloradoense (Hend) = Arkhangelsckiceras amudariensis (Arkh.), Puzosia chivensis Arkh, Proplacenticeras khoresmense (Lah.), Mammites nodosoides chivensis Arkh., Collignoniceras woolgari Mant.; marine bivalve mollusks - Inoceramus labiatus Schloth., Liostrea jaxartensis Sim. and others

Age

Belongs to the upper Cenomanian-middle Turonian, according to R.P. Soboleva (423), - to the Cenomanian and Turonian, according to S.S. Shulz (ml.) (509), - to the Turonian and is the upper suite of the Aralo-Kyzylkum series (508).

Age Span:

Beginning stage:

Cenomanian

Fraction up in beginning stage:

0.7

Beginning date (Ma):

95.88

Ending stage:

Turonian

Fraction up in the ending stage:

0.7

Ending date (Ma):

90.74

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)”