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Compiled by: Jacques LeBlanc (2022), Stratigraphic Lexicon: The Sedimentary Formations of The Republic of Niger, Africa. Colnes Publishing (Tallin, Estonia), 365 pp. For more information see "About"

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Farrazekat Formation

Farrazekat Fm

Period:

Devonian

Age Interval:

Upper Devonian; Famennian (1)

Province:
Iullemmeden Basin - Tim Mersoï Sub-basin

Type Locality and Naming

Joulia, 1959a; Claret & Tempère, 1968.

References: Joulia, 1959a; Lessard, 1961; Claret & Tempère, 1968; Valsardieu, 1971; Fabre et al., 1983; Coquel et al., 1995.

Synonym: Grès de Farrazekat; Farazekat (misspelling). Joulia (1959) and Claret & Tempère (1968) spell it with two “rr”; Valsardieu (1971) mistakenly spells it with one “r”, and Fabre et al. (1983) spell it again with two “rr”. In this lexicon, the spelling is kept with two “rr”. Earlier authors (Joulia, 1959a; Lessard, 1961; Claret & Tempère, 1968) had the Farrazekat subdivided into Lower, Middle and Upper Sandstones. Valsardieu (1971) renamed the upper part of the Farrazekat as the "Teragh Sandstones and conglomerates" and kept the Lower & Middle Units as the Farrazekat proper. Equivalent(s): Claret & Tempère (1968) include it as a Member of the Touaret Fm

Lithology and Thickness

According to Joulia (1959a), coarse-grained continental sandstone with Protolepidodendron. On page 51 of Valsardieu (1971), it is stated a thickness of 170 m for this formation in the Touaret area.

Lithology Pattern:

Coarse-grained sandstone

Relationships and Distribution

Lower contact

Underlying unit is the Taberia Fm

Upper contact

Overlying unit is the Teragh Fm

Regional extent

GeoJSON

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Fossils

Plants (page 51 of Valsardieu, 1971) and Spirophytons (see fossil-location map with Taberia Fm).

Age

Upper Devonian; Famennian (Valsardieu, 1971).

Age Span:

Beginning stage:

Famennian

Fraction up in beginning stage:

0.25

Beginning date (Ma):

368.15

Ending stage:

Famennian

Fraction up in the ending stage:

1.0

Ending date (Ma):

359.30

Depositional setting

Continental

Depositional pattern:

Additional Information

Compiler:

Jacques LeBlanc (2022), Stratigraphic Lexicon: The Sedimentary Formations of The Republic of Niger, Africa. Colnes Publishing (Tallin, Estonia), 365 pp. https://doi.org/10.47909/978-9916-9760-6-7 (or via https://sites.google.com/site/leblancjacques)