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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Fand Formation

Fand Fm

Period:

Triassic

Age Interval:

Lower-Middle Triassic, S4

Province:
North Tajik

Type Locality and Naming

Synonym: Fand suite, Фанекая свита

Reference section:

Lithology and Thickness

In the lower part is made up of lens-shaped interbedding of cross-bedded gravelites-breccias, coarse-grained quartz sandstones, fine-gravel conglomerates. In the upper part, the sorting of material improves, conglomerates are observed less frequently; among the gravel-sandy rocks, there are interlayers of claystones. The thickness of the suite is 60-115 m.

Lithology Pattern:

Aus Conglomerate

Relationships and Distribution

Lower contact

The considered deposits lie either sharply unconformably on the rocks of the Paleozoic, or with a slight erosion on the formations of the Ravat Fm previously attributed to the Upper Triassic deposits, and according to our and R.Z. Gengkina's data, included in the Lower Triassic section.

Upper contact

It is overlain by Cretaceous red beds with an unclear contact.

Regional extent

GeoJSON

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Fossils

In the upper half of the suite, the author has collected and identified plant remains of Neocalamites sp., Phlebopteris braunii Goepp., Thaumatopteris hissarica Brick, Hissaropteris jagnobensis Kuz. et Sixt., Cladophlebis sp., Coniopteris hymenophylloides (Brongn.) Sew., Ginkgo ferganensis Brick, etc.

Age

The fossil assemblage allows attributing the considered deposits to the Lower to Middle Triassic.

Age Span:

Beginning stage:

Olenekian

Fraction up in beginning stage:

0.5

Beginning date (Ma):

248.29

Ending stage:

Anisian

Fraction up in the ending stage:

1.0

Ending date (Ma):

241.46

Depositional setting

Depositional pattern:

Additional Information

Compiler:

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