Opichek Formation

Opichek Fm

Period:

Paleogene

Age Interval:

Lower Eocene (Ypresian), F3

Province:
Fergana

Type Locality and Naming

At the Opichek waterfall, N. Fergana. Stratotype in the area of the Opichek waterfall (Kichiksumsarsay).

Synonym: Opichek Suite, Оничкеская св.

Lithology and Thickness

Consists of two parts. Lower - white, light gray limestones, locally sandy; upper - red, greenish-gray, fine- to medium-clastic gravels, locally cross-bedded (Naryn). Gravel is poorly sorted with well-rounded and angular clasts. Thickness is up to 41m (Naryn).

Lithology Pattern:

Sandy limestone

Relationships and Distribution

Lower contact

Conformably overlies the Gavasay Fm

Upper contact

It is conformably overlain by the Alay Fm, but schematic stratigraphic column indicates Surkhin Fm

Regional extent

Northern Fergana. U.M. Rasulov (1991f.) separates the upper part of the suite into the Surkhin Fm. It is correlated with the middle part of the Givar Fm of the South-Western Gissar (Abdusamatov, 1991f.).

GeoJSON

null

Fossils

Contains a poor complex of marine bivalve mollusks - Ostrea hemiglobosa Rom., Pycnodonta errara (Vial.), Crassatella scutellaria Desh., Lucina sp., Cardium sp.

Age

It belongs to the Ypresian stage of the Lower Eocene.

Age Span:

Beginning stage:

Ypresian

Fraction up in beginning stage:

0.0

Beginning date (Ma):

56.00

Ending stage:

Ypresian

Fraction up in the ending stage:

0.5

Ending date (Ma):

52.04

Depositional setting

Depositional pattern:

Additional Information

Compiler:

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