Arpalyk Formation

Arpalyk Fm

Period:

Devonian

Age Interval:

Middle Devonian (Eifelian-Givetian), F10b

Province:
Fergana

Type Locality and Naming

In the Arpalik Mountains, Alai Range (Fergana?). G.A. Yarushinsky, L.V. Kushnaryov in 1956 (176, pp.16-17). Stratotype on the left bank of the Isfayram River. Lowermost formation in the Alay Gr

Synonym: Arpalyk Suite, Арпалыкская св.

Lithology and Thickness

Dolomites. In some places, lenses of sandstones and conglomerate-breccias are noted in the lower part, and in the top of the body, albite porphyries and orthoporphies. Up to 150-500m thick.

Lithology Pattern:

Dolomite

Relationships and Distribution

Lower contact

Unconformably overlies various mountains of the Silurian, and beyond the borders of Uzbekistan, on dolomites of the lower-middle Devonian

Upper contact

Overlain conformably, sometimes with erosion, by the Boordin Fm

Regional extent

Alai Range.

GeoJSON

null

Fossils

Contains stromatoporoids - Amphipora ramosa Phill. and others; rugose corals - Alaiophyllum jaruschewskyi Gor.; tabulates Favistella rhenana Frech., brachiopods - Stringocephalus burtini Defr., Stringocephalus primordiale Wakd. and others.

Age

Belongs to the Givetian stage of the Middle Devonian. (441; 460).

Age Span:

Beginning stage:

Givetian

Fraction up in beginning stage:

0.0

Beginning date (Ma):

385.30

Ending stage:

Givetian

Fraction up in the ending stage:

0.8

Ending date (Ma):

380.18

Depositional setting

Depositional pattern:

Additional Information

Compiler:

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