Akchop Formation

Akchop Fm

Period:

Neogene

Age Interval:

Upper Pliocene, F2, F4

Province:
Fergana

Type Locality and Naming

Along the Akchop Mts., N.-W. Fergana. M.N. Gramm, 1958 (467, p.171).

Synonym: Akchopskaya Suite, Акчопская св.

Lithology and Thickness

In the N.-W. Fergana, it includes sandstones, clays, and siltstone (aleurolites), subordinate limestones, gray and brown (brown suite of N.P. Vasilykovsky, (126). In the northern and northeastern part of the Fergana Depression - siltstone (aleurolites), sandstones, gravels, conglomerates, brown, brownish-gray. In the marginal eastern and southern part of the depression, it was destroyed by subsequent erosion. Thickness approximately 900m.

Lithology Pattern:

Sandy_claystone

Relationships and Distribution

Lower contact

It lies with erosion on the Bakhmaltepin Fm or Obchak Fm

Upper contact

With erosion it is covered by the Kepeli Fm

Regional extent

In the N.-W. Fergana.

GeoJSON

null

Fossils

Contains mammals Hipparion sp., Lepus sp., Tragocerina sp., Arinocerotidae gen.?, Bovidae gen., Mastodon sp.; gastropods - Limma ex gr. ovata Drap., Planorbis leocastona Millet., P. aff. collisus Bogd.; ostracods - Cypria ex gr. expolita Schn. n. msc., C. combiba Liv., C. angulata Miller., Paracandona enplectella (Br. et Norm.), Eucypris concinna Schn., E. porsugelensis Mand., E. vitalianus Schn. n. mse., E. concinna Schn., Cyprinotus vialove Schn., Zonocypris elangata Schn.

Age

Age, Along A., mid-Pliocene. M.N. Gramm (180) correlated it with the brown suite in the 1st scheme of N.P. Vasilykovsky (126). Along V.I. Popov et al. (166), it corresponds to the n.-mid-Pliocene Tavildarinskaya suite, Yu.R. Smolnikov et al. (1973) attributed it to the upper Pliocene. Along B.I. Pinhasov, it forms the lower part of the brown-colored molasse formation of the Upper Tien Shan series. It belongs to the upper Pliocene Along the complex of organic remains and its position below the Kepelian suite with Archidiscodon meridionalis meridionalis Nesti (Eopleistocene-Apsheron). Accepted in the Chatkal-Kuramin series of sheets, scale 1:50000, 1998.

Age Span:

Beginning stage:

Piacenzian

Fraction up in beginning stage:

0.0

Beginning date (Ma):

3.60

Ending stage:

Piacenzian

Fraction up in the ending stage:

1.0

Ending date (Ma):

2.58

Depositional setting

Depositional pattern:

Additional Information

Compiler:

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