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

Kaltadavan Formation

Kaltadavan Fm

Period:

Ordovician

Age Interval:

middle-late Ordovician, N4

Province:
Nuratau

Type Locality and Naming

By the river Kal'tadavan, N. Nuratau Ridge. P.N. Podkopaev et al. in 1961 (1964). Stratotype Along Kaltadavansay.

Synonym: Kal'tadavanskaya Suite, Калтадаванская св.

Lithology and Thickness

Sandstones, siltstone (aleurolites), slates with layers (10-15 cm) of gravelites. Sandstones and gravelites are predominantly polymictic, dark gray, bluish-gray, light and gray-green, containing layers of tuffaceous varieties, among which among quartz, feldspar, chert, quartzite, various slate fragments are present effusives of basic and intermediate composition, siliceous-mica, siliceous-chlorite, quartz-sericite dark and light green, dark gray. Often, sandstones from gravel to fine-grained through silty (aleurolitic) varieties are replaced by siltstone (aleurolites), they are characterized by gradational bedding. Some sandstone layers contain spherical and ellipsoidal bodies (up to 2 m in diameter), composed of sandstones with carbonate cement. On the surface of sandstone and siltstone (aleurolite) layers, there are numerous hieroglyphs caused by bottom currents: drag marks of fragments, erosion by turbulent currents, traces of sediment washout, etc. The formation of sediments is associated with turbidite currents. Thickness 400-600m.

Lithology Pattern:

Fine-grained sandstone

Relationships and Distribution

Lower contact

Reliable stratigraphic contacts have not been established.

Upper contact

Reliable stratigraphic contacts have not been established.

Regional extent

Northern slope and water-dividing part of the North Nuratau ridge, central part of the Koytash Mountains. It is correlated with the Marjanbulak Fm of the Marjanbulak uplift.

GeoJSON

null

Fossils

In siltstone (aleurolites), Ordovician conodonts - Drepanoistodus sp. and middle Ordovician chitinozoa - Lagenochitina prussica Eis., Desmochitina minor f. typica Eis., D. minor f. frinacea Eis. and others.

Age

P.N. Podkopaev et al. (1964) conditionally attributed the formation to the lower Silurian; E.V. Chukarov et al. (1968, 1971) - to the upper or middle Cambrian; M.A. Akhmedjanov et al. (72) - to the middle Ordovician. On geological maps and in legends by R.R. Usmanov et al. (1988, 1999), V.S. Korsakov et al. (1993) it is conditionally attributed to the Vendian-lower Cambrian based on the position under the Zhivachisay Fm. Z.M. Abdazimova et al. (1985, 1993, 1996; 165) believe that fragments of the Kaltadavan Fm are in tectonic alternation with the Zhivachisay Fm and, based on the findings of conodonts and chitinozoa, determine the age of the Kaltadavan Fm - middle-late Ordovician.

Age Span:

Beginning stage:

Darriwilian

Fraction up in beginning stage:

0.5

Beginning date (Ma):

463.80

Ending stage:

Katian

Fraction up in the ending stage:

1.0

Ending date (Ma):

445.21

Depositional setting

Depositional pattern:

Additional Information

Compiler:

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