Karzhantau Formation

Karzhantau Fm

Period:

Carboniferous

Age Interval:

Gzhelian, CK2, CK3

Province:
Chatkal-Kuramin Region

Type Locality and Naming

In the Karzhantau Mountains. V. P. Korzhayev et al., 1984 (473, p. 176). Stratotype in Shurabsai.

Synonym: Karzhantau Suite, Каржантауская св.

Lithology and Thickness

Repeated alternation of homodromic groups of igneous rocks: trachybasalts, trachyandesibasalts, trachyandesites, trachytes, their tuffs, trachydacites, trachyriodacites, trachyriolites, quartz trachytes with their tuffs and ignimbrites, throughout the section, horizons of volcanomictic sandstones are encountered. At the base - basal conglomerates (thickness 100-250m), higher - locally volcanomictic sandstones, siltstone (aleurolites), interlayers and lenses of limestones. Thickness more than 2000m.

Lithology Pattern:

Volcanic_ash

Relationships and Distribution

Lower contact

Lies with a sharp unconformity on the Minbulak Fm and the Uya Fm. Along I.M. Nigmadzhanov, also on the Dzhegirgen Fm.

Upper contact

Overlain with unconformity by the Oyasay Fm and intruded by rocks of its vent and subvolcanic facies (473).

Regional extent

GeoJSON

null

Fossils

Age

No precise paleontological evidence of age. Absolute age - 293-298 million years (K-Ar method) (473). Taking this into account and based on its position in the section, the age of the suite is Gzhelian (?) of the late Carboniferous (450; 460).

Age Span:

Beginning stage:

Gzhelian

Fraction up in beginning stage:

0.0

Beginning date (Ma):

303.68

Ending stage:

Gzhelian

Fraction up in the ending stage:

1.0

Ending date (Ma):

298.89

Depositional setting

Depositional pattern:

Additional Information

Compiler:

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