Nauvalin Formation

Nauvalin Fm

Period:

Carboniferous

Age Interval:

Bashkirian, CK4

Province:
Chatkal-Kuramin Region

Type Locality and Naming

Along the r. Naualy, right tributary of the r. Pskem, Ugamsky khrebet. O.I. Sergunyukova, 1959 (382, p. 65), as Namurian. Stratotype along the Yakhaksay, right tributary of the r. Naualy.

Synonym: Nauvalinskaya Svita, Наувалинская св.

Lithology and Thickness

Variegated clotted-oolitic, clotted-algal, organogenic limestones with siliceous inclusions. Thickness 300-500m.

Lithology Pattern:

Oolitic limestone

Relationships and Distribution

Lower contact

Along the bedding, it lies on the Keltemashat Fm

Upper contact

It is overlain conformably by the purely carbonate Yakhak Fm (lower-middle course of the rivers Pskem, Ugam), as well as the carbonate-terrigenous-volcanogenic Surkhat Fm. (upper reaches of the r. Pskem) (Tkachev et al., (1996f.)

Regional extent

Pskem and Ugam ranges, basin of the upper reaches of the Ugam River.

GeoJSON

null

Fossils

Contains brachiopods - Linoproductus corrugatus M'Coy, Productus concinnus Sow., Spirifer bisulcatus Sow.; foraminifera - Plectostaffella varvariensis Br. et P., Globivalvulina parva N. Tch., Millerella umbilicata Kir.; conodonts Declinognathodus noduliferus El. et Gr., D. lateralis (Hig.).

Age

Middle Carboniferous Bashkirian horizon lower subhorizon

Age Span:

Beginning stage:

Bashkirian

Fraction up in beginning stage:

0.2

Beginning date (Ma):

321.75

Ending stage:

Bashkirian

Fraction up in the ending stage:

0.3

Ending date (Ma):

320.93

Depositional setting

Depositional pattern:

Additional Information

Compiler:

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