Uluk Formation

Uluk Fm

Period:

Permian

Age Interval:

Sakmarian, F3a

Province:
Fergana

Type Locality and Naming

Named after the village of Uluk, southern slope of Mount Bosbutau, N. Fergana. F.R. Benesh in 1955 (103, p. 10). Stratotype - southern slope of Mount Bosbutau.

Synonym: Uluk Suite, Улукская св.

Lithology and Thickness

Sandstones, less frequently siltstone (aleurite), claystone, and conglomerates. The latter are more common in the section of the Chanach River, where they form layers up to 20-25 m thick. Thickness of the suite is about 1000 m.

Lithology Pattern:

Sandstone

Relationships and Distribution

Lower contact

It lies with deep erosion on the Mamay Fm

Upper contact

covering deposits are unknown

Regional extent

Northern Fergana, southeastern slope of the Chatkal ridge, Mount Bosbutau, interfluve of the Padsheata-Chanach rivers.

GeoJSON

null

Fossils

In interlayers of sandy and detrital limestones, foraminifers are found - Shihanella celebrata (Bensh), S. parapulchra (Bensh), S. ex gr. karagasensis (Raus.), Concavutella curtata (Raus.), C. proconcavutas (Raus.), C. irregularissima effusa (Bensh), C. lassula (Bensh), C. buranchini (Raus.), Verneuilites ex gr. urdalensis (Raus.), Monodiexodina ferganica (M.-Macl.), Chalaroschwagerina sokolovi (M.-Macl.), Cuniculinella narynica Bensh, characteristic of the upper part of the Sakmarian stage zone Cuniculinella narynica. In sandstones of the suite on the southern slope of Mount Bosbutau (Mazarcolsay), large spore-bearing cones Sigillariostrobus ex gr. tieghemii Leill. were found.

Age

Along foraminifer complexes, it belongs to the Sakmarian stage of the Lower Permian (165; 439; 460).

Age Span:

Beginning stage:

Sakmarian

Fraction up in beginning stage:

0.0

Beginning date (Ma):

293.52

Ending stage:

Sakmarian

Fraction up in the ending stage:

1.0

Ending date (Ma):

290.51

Depositional setting

Depositional pattern:

Additional Information

Compiler:

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