Cenozoic

Cretaceous

Jurassic

Triassic

Permian

Carboniferous

Devonian

Silurian

Ordovician

Cambrian

Neoproterozoic

Main source = Baratov, R.B., et al. (1976). Subdivisions of stratified and intrusive rocks of Tajikistan. Publishing House "Donish", Dushanbe, 269 pp. plus tables. Provided by Dr. Jovid Aminov, Nazarbayev University, Astana, Kazakhstan Translated to English by the GeoGPT group, Zhejiang Lab, Hangzhou, China--see About

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Upper Cambrian Formation

Upper Cambrian Fm

Period:

Cambrian

Age Interval:

Upper Cambrian, S2

Province:
North Tajik

Type Locality and Naming

Synonym: Upper Division

Reference section:

Lithology and Thickness

Clay slates, claystones, limestones. It is represented by alternations of dark gray clay slates, claystones, limestones, and sandstones, which contain rare lenses of conglomerates. The thickness is 200 m. The number of slates increases up the section. At the bottom, coarse-grained sandstones and conglomerates usually predominate, containing (Yaskovich, 1968) in the pebbles remains of trilobites of the Mayan stage.

Lithology Pattern:

Clayey limestone

Relationships and Distribution

Lower contact

On the rocks of the Mayan stage, the upper Cambrian lies with erosion, but without angular discordance.

Upper contact

It is overlain by terrigenous rocks of the Lower Ordovician in conformity.

Regional extent

It is widespread in the same locations as the middle division i.e., in Central Tajikistan (Zeravshan-Gissar and South Gissar districts) and in the Northern Pamir.

GeoJSON

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Fossils

In the interlayers of limestones and carbonate cement of conglomerates, there are trilobites characteristic of the upper Cambrian: Homagnostus obesus Belt., H. asiaticum Hajr., Lisania sp., Onchonotellus oburdonicus Hajr., Prochuangia minuscula Hajr., Proceratopyge schaganica Hajr,, and others (Geol. USSR, vol. 23, 1972).

Age

Upper Cambrian

Age Span:

Beginning stage:

Paibian

Fraction up in beginning stage:

0.0

Beginning date (Ma):

497.00

Ending stage:

Cambrian Stage 10

Fraction up in the ending stage:

1.0

Ending date (Ma):

486.85

Depositional setting

Depositional pattern:

Additional Information

Compiler:

Extracted from Baratov, R. B. (1976). Subdivisions of stratified and intrusive rocks of Tajikistan. Donish, Dushanbe, 276.