Lower TianShan Gr

Period:

Paleogene, Neogene

Age Interval:

Oligocene-middle Miocene, CK11

Province:
Chatkal-Kuramin Region

Type Locality and Naming

Part of the Tien Shan complex. B. I. Pinhasov, 1985 (145, pp.15-17). Accepted in the Chatkal-Kuraminskaya series sheets of the m-1:50000, 1998.

Synonym: Lower Tienshan Series, Нижнетяньшанская сер.

Lithology and Thickness

Represented by a red-colored molasse formation, corresponding to the initial stage of mountain formation with a small amplitude of vertical movements, which caused the formation of low-mountain relief. In the lower part, brightly red clays and siltstone (aleurolites) (conditionally Oligocene-n. Miocene) dominate, in the upper, main in thickness, - brick-red siltstone (aleurolites) with sandstones, gravelites, and conglomerates (n.-sr. Miocene). Thickness up to 1800 m.

Lithology Pattern:

Siltstone

Relationships and Distribution

Lower contact

With a slight erosion, it overlies the upper Eocene Khanabad sv. (Fergana) and all older mountains, up to the Paleozoic.

Upper contact

Along the overlap, it is covered by the Middle TienShan Gr, or discordantly by the Upper TienShan Gr.

Regional extent

Intermontane depressions of Tien Shan, foothill zone (Fergana and Zarafshan depressions, Pre-Tashkent region). In the Fergana Depression, the series is represented by the Sum Fm and Mailisay Fm. Along the frontal ranges of the Tien Shan and in the Tashkent-Golodnostepsk Depression, it corresponds to the Chulin Fm. In the Bayrakum and Ergashkuduk depressions, the lower part of the Chulin Fm. is facially replaced by the marine Sarbatyr Fm., and the upper part of its section transitions into the brick-red molassoid t. of the Agitmin Fm. The latter, in Khorezm, in the upper part, is interbedded, and then completely replaced by marine deposits of the Kotsakhur-middle Sarmatian (346),

GeoJSON

null

Fossils

Contains mollusks, ostracods, foraminifers (see Sum Fm and Mailisay Fm). Vertebrate fauna has not been found on the territory of Uzbekistan. It is known in the red-colored molasses of Kazakhstan and Kyrgyzstan. In the Ili Depression (S.-E. Kazakhstan) in the deposits of the series (Aktau Fm) buried remains of indricotherian (Oligocene), paraceratherian (Caucasus) fauna, as well as fauna and flora corresponding to the Kushuksky level (Sakaraul). L.K. Gabuniya (455) does not exclude the affiliation of the Kushukskaya fauna to the Kotsakhur. In the intermontane depressions of Kyrgyzstan, where the series corresponds to the deposits of the Kyrgyz red-colored complex (510), there are remains of hipparion fauna - Samotherium sp, Gazella sp., giraffe teeth, large antelope (70; 444),

Age

Fossil data indicates the affiliation of the upper part of the section of the series to the Sarmatian. B.I. Pinhasov (145) initially attributed the series to the Oligocene-l. Miocene. With the transfer of the main part of the Sarmatian in span to the middle Miocene, the age of the series is Oligocene-middle Miocene.

Age Span:

Beginning stage:

Rupelian

Fraction up in beginning stage:

0.0

Beginning date (Ma):

33.90

Ending stage:

Serravallian

Fraction up in the ending stage:

1.0

Ending date (Ma):

11.63

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)”