Kafaklin Formation

Kafaklin Fm

Period:

Jurassic

Age Interval:

late Bajocian - early Callovian, U3

Province:
Ustyurt-Sultanuzdag

Type Locality and Naming

Named after the Kafakli River, Tuarkyr, west Turkmenistan. K. K. Myshrykov, 1956 (292, p.120).

Synonym: Kafakli Suite, Кафаклинская св.

Lithology and Thickness

Terrigenous deposits, characterized by the predominance of clays, less frequently interlayers of siltstone (aleurolites), sandstones. Characterized by dark gray and gray-green color with spots and streaks of bluish-green, grayish-purple color. Lithological homogeneity is preserved only in the lower parts of the section. On Mangyshlak, tuffites, carbonaceous clays, coals are noted. Thickness 80-120-236m.

Lithology Pattern:

Sandy_claystone

Relationships and Distribution

Lower contact

The Kafaklin Fm of Tuarkyr transgressively overlies the Ogryadag Fm, Bazaryn Fm, Sarydiiyirman Fm; and on Ustyurt - the Raushan Fm.

Upper contact

It is overlain transgressively by the Aginish Fm (in troughs), or by the Shordzhin Fm (in uplift zones).

Regional extent

Exposed on Tuarkyr and in the eastern Mangyshlak. Revealed by wells in Mangyshlak, Ustyurt, and in the Takhtakair district. Facies analogue is the Baysun Fm. The Kafaklin Fm is included in the Baysun Horizon (252). Corresponds in the lower half to the productive Akchalak Horizon a1, and in the upper half to the V productive Alambek Horizon (165).

GeoJSON

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Fossils

Contains freshwater bivalve mollusks - Acyrena busimensis Leb., Tutuella chachlovi Rag. and others; marine ostracods - Palaeocytheridea ciraria Lub., P. velamina Mand. and others; large plant remains - Nilssonia vittaeformis Pryn., Ptillophyllum Pecten Phill. and others of late Bajocian - early Callovian age (446). Spore and pollen complex - Cyathidites minor Couper (10-34%), C. junctus (K-M.) Alim. (8-10%), Lycopodiumsporites sp. (0-5%), Taurocusporites sp. (0-5%), Classopollis sp. (0-30%), Disaccites sp. (2-35%), Ginkgocycadophytus sp. (0-13%), Porinopollenites sp. (2-3%), Inaeperturopollenites sp. (9-5%).

Age

Age determined as late Bajocian - early Callovian. Put 25% up in Bathonian (TO FIT) in Lexicon

Age Span:

Beginning stage:

Bathonian

Fraction up in beginning stage:

0.25

Beginning date (Ma):

167.45

Ending stage:

Bathonian

Fraction up in the ending stage:

1.0

Ending date (Ma):

165.29

Depositional setting

Depositional pattern:

Additional Information

Compiler:

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