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

Abartkan Beds Formation

Abartkan Beds Fm

Period:

Silurian

Age Interval:

upper Wenlock - lower Ludlow, N2

Province:
Nuratau

Type Locality and Naming

Along the Abartkan valley, southern slope of Mount Merishkor, near the village of Chashma-Zrak, North Nuratau Range. A.I. Kim, N.M. Larin, 1966 (368, pp.91-92). Stratotype in the Abartkan valley. They form the upper part of the Khatyntbulak Fm

Synonym: Abartkan Layers, Абартканские сл.

Lithology and Thickness

Lithologically divided into three parts:

Upper - variegated siltstone (aleurolites) with lenses of clayey limestones. Thickness 27-40m.

Middle - pelitomorphic limestones with layers of crinoid-detrital varieties. Thickness 8-13m.

Lower - siltstone (aleurolites), sandstones. Thickness 30m.

Lithology Pattern:

Siltstone

Relationships and Distribution

Lower contact

Conformably overlies Ishkap Beds Fm

Upper contact

Overlain by Shalyn Beds Fm of the Chaltash Fm

Regional extent

North Nuratau Range, Ishkap and Abartkan valleys. According to S.K. Pivnyuk et al. (1980), the lower part of the Abartkan Beds Fm is an age equivalent of the upper part of the Aidynsay Beds Fm, and the upper part is equivalent to the Dzhush Beds Fm.

GeoJSON

null

Fossils

Upper – Contains brachiopods - Conchidium biloculare asiaticum Sap. et Ruk.; graptolites - Pristiograptus ex gr. Dubius (Suess.), P. cf. tumescens (Wood.), Neodiversograptus nilssoni (Lapw.), Saetograptus leintwardinensis (Hopk.).

Middle – Contains brachiopods Conchidium biloculare asiaticum Sap. et Ruk. and graptolites - Monograptus ludensis Murch. and others

Lower – Contains graptolites - Gothograptus nassa Holm.

Age

Early Silurian, late Wenlock to late Silurian, early Ludlow.

Age Span:

Beginning stage:

Homerian

Fraction up in beginning stage:

0.5

Beginning date (Ma):

428.68

Ending stage:

Gorstian

Fraction up in the ending stage:

1.0

Ending date (Ma):

425.01

Depositional setting

Depositional pattern:

Additional Information

Compiler:

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