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

Vardashat Formation

Vardashat Fm

Period:

Ordovician

Age Interval:

Middle Ordovician, Z3

Province:
Zarafshan-N.Gissar

Type Locality and Naming

Along the village of Wardash, Turkestan Ridge, Tajikistan. N.A. Kozar in 1985 (460, p.69). Stratotype along the Rukhshif River.

Synonym: Vardash Fm, Vardashtskaya Suite, Вардашская св.

Lithology and Thickness

Phyllitic, carbonaceous-clayey, albite-quartz-schistose slates, meta-siltstone (aleurolites), quartz sandstones, rarely layers of siliceous rocks. Thickness more than 1200 m.

Lithology Pattern:

Sandy_claystone

Relationships and Distribution

Lower contact

Contacts with the underlying Rukhshif Fm

Upper contact

Overlying Lower Llandovery deposits are normal stratigraphic. (460).

Regional extent

North slope of the Chumkartau Mountains and central part of the Turkestan Ridge.

GeoJSON

null

Fossils

Throughout the section, numerous Tremadocian graptolites - Dictyonema cf. flabelliforme intermedium Prantl. et Prib., D. cf. scitulum Harr. et Keble., D. aff. murrayi Hall., Bryograptus sp., Callograptus sinuis Ma., C. sp., Tetragraptus aff. approximatus (Nich.) and others; Arenig - Pendeograptus fruticosus (Hall.), P. clarkei (Rued.), Dichograptus separatus Elles., Tetragraptus pygmaeus (Rued.), T. ruedemanni Tzaj., Paratetragraptus approximatus (Hall.), Eotetragraptus cf. sidenbladhi (Linn.), Phyllograptus densus Tqt., Corymbograptus cf. nitidus (Hall.) and others; middle Ordovician - Isograptus divergensis (Harris.), Glyptograptus aff. tereticulatus (His.), Glossograptus cf. hincksii (Hopk.), Amplexograptus sp., Didymograptus sp. and others.

Age

Fossil data indicates Tremadocian, middle Ordovician.

Age Span:

Beginning stage:

Tremadocian

Fraction up in beginning stage:

0.0

Beginning date (Ma):

486.85

Ending stage:

Hirnantian

Fraction up in the ending stage:

1.0

Ending date (Ma):

443.07

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)”