Neogene

Paleogene

Cretaceous

Jurassic

Triassic

Permian

Carboniferous

Devonian

Silurian

Ordovician

Cambrian

Neoproterozoic

Mesoproterozoic

Paleoproterozoic

Main source = Abduazimova, Z.M. (Ed.), 2001. Stratigraphic Dictionary of Uzbekistan. IMR (Institute of Mineral Resources), Tashkent, 580 pp. (In Russian) Translated to English by the GeoGPT group, Zhejiang Lab, Hangzhou, China--see About

Darasay Formation

Darasay Fm

Period:

Carboniferous

Age Interval:

Middle Carboniferous (?), N8

Province:
Nuratau

Type Locality and Naming

Along the Darasai stream, Southern Nuratau ridge. Y.V. Shumakov in 1973 (460, p. 193). Stratotype along the Darasai.

Synonym: Darasai Suite, Дарасайская св., Sub-Aktau Fm

Lithology and Thickness

Quartz-mica slates, hornfels, quartzitic sandstones, calcareous sandstones with lenses of marbles and conglomerates. In the conglomerates, an abundance of marble pebbles, similar to the marbles of the Bakhiltau Fm. Thickness 400m.

Lithology Pattern:

Clayey sandstone

Relationships and Distribution

Lower contact

Relationships with surrounding formations are unclear.

Upper contact

It is assumed that the suite unconformably overlies the Aktau marbles (Aktau Gr).

Regional extent

Bakhiltau Mountains from the Tutak River in the east to the Gazgan settlement in the west.

GeoJSON

null

Fossils

Crinoids - Pentagonopentagonalis subpennatus Yelt., Pentagonocyclicus radialis Yelt., Pisocrinus astericus (Schew.), Desmidocrinus ligatus (Quenst.) and others not in pebbles, but in interlayers of limestones.

Age

The age is conditionally determined as Middle Carboniferous based on collections of Silurian-Devonian and Devonian-early Carboniferous fauna in the pebbles of the conglomerates (Piven' et al., 1976). Previously, these deposits were referred to as the Sub-Aktau Fm by K.K. Pyatkov et al. (1961; 1975), with an age interpreted as late Silurian-early Devonian. I.A. Pyanova et al. (371) consider the age of the Darasay Fm to be early-middle Devonian based on finds of late Silurian-early Devonian crinoids. These deposits are assigned to the Middle Carboniferous by Yu.I. Loskin et al. (1986), R.S. Khan et al. (1989), R.R. Usmanov et al. (1999).

Age Span:

Beginning stage:

Moscovian

Fraction up in beginning stage:

0.5

Beginning date (Ma):

311.09

Ending stage:

Moscovian

Fraction up in the ending stage:

1.0

Ending date (Ma):

307.02

Depositional setting

Depositional pattern:

Additional Information

Compiler:

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