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

Chashmankalon Formation

Chashmankalon Fm

Period:

Ordovician

Age Interval:

Ashgillian, Z1b

Province:
Zarafshan-N.Gissar

Type Locality and Naming

Along the Chashmankalon River, Zarafshan Range. A.I. Kim, Yu.I. Apekina, M.V. Erina, 1975 (225, p.912). Stratotype in the Shakhriomona area.

Synonym: Chashmankalon Layers, Чашманкалонские сл.

Lithology and Thickness

Polymictic, ocher, less frequently quartz-feldspar, inequigranular sandstones with layers of foliated, dark-green siltstone (aleurolites) and lenses of calcareous sandstones in the upper part. Thickness 44-79m.

Lithology Pattern:

Fine-grained sandstone

Relationships and Distribution

Lower contact

Conformably overlie the Obikandinian beds

Upper contact

Overlain by the Archaly Fm [<- No entries in this Lexicon with spellings close to either of these.].

Regional extent

West part of the Zarafshan Range.

GeoJSON

null

Fossils

Characteristic tabulates - Lyopora regularis Kim; brachiopods - Dolerorthis intermedius Rozm., Sowerbyella intricata Rozm., Eoanastrophia antiquata Nikif. et Sap., Holorhynchus giganteus Kiaer., Synchomalonotus sulcatus Kolob., Platylichas laxatus M'Coy; trilobites - Illaenus schmidti Nieszk., Medinecrinus lenitus Stuk., Xenocrinus? quadriaugulatus Stuk.; graptolites - Pacificograptus pacificus kimi Koren., Dimorphosiphon magnum Gn., Contexta tumidula Gn.

Age

Belong to the lower Ashgillian stage (348). M.V. Erina. Str. beds (443).

Age Span:

Beginning stage:

Katian

Fraction up in beginning stage:

0.5

Beginning date (Ma):

448.98

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