Shyut Formation

Shyut Fm

Period:

Carboniferous

Age Interval:

Lower-Middle Carboniferous (Visean-Bashkirian), F10c

Province:
Fergana

Type Locality and Naming

Along the Shyut River, Alay Range. V. T. Kotel'nikova et al. in 1958 (176, pp. 7-28).

Synonym: Shyutskaya Suite, Сюгетская св.

Lithology and Thickness

Interbedded sandstones, siltstone (aleurolites), conglomerates, clayey and siliceous slates, limestones, gravellites, cherts. Occasionally, in the lower part of the suite - rare layers of alites, basic effusives, and their tuffs. Thickness more than 250m, in some areas - 700m.

Lithology Pattern:

Sandstone

Relationships and Distribution

Lower contact

Lies almost everywhere in a continuous section with Lower Carboniferous limestones, in most areas overlying formations are absent

Upper contact

In some areas transgressively overlain by the Tolubay Fm or younger deposits

Regional extent

South Fergana, northern foothills of the Alay Range, interfluve of the Sokh and Shahimardan rivers. The most complete section in Kyrgyzstan.

GeoJSON

null

Fossils

Contains foraminifers Eostaffella mosquensis Viss., E. protvae Raus., Neoarchaediscus micus Pojark., N. ex gr. gregorii Dain., Pseudostaffella antiqua Dutk., widespread in Visean, Serpukhovian, and Bashkirian deposits; Serpukhovian and Bashkirian Goniatites Cravenoceras cf. merriami Young., Schartymites cf. barbotanus Vern.; Serpukhovian and Bashkirian brachiopods - Productus concinnus Sow., Spirifer bisulcatus Sow., Eomarginifera schartimiensis Jan.

Age

Belongs to the Lower-Middle Carboniferous within the Visean-Bashkirian stage (439).

Age Span:

Beginning stage:

Visean

Fraction up in beginning stage:

0.0

Beginning date (Ma):

346.73

Ending stage:

Moscovian

Fraction up in the ending stage:

0.1

Ending date (Ma):

314.34

Depositional setting

Depositional pattern:

Additional Information

Compiler:

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