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Cretaceous

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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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Teragh Formation

Teragh Fm

Period:

Carboniferous

Age Interval:

Lower Carboniferous (Lower Tournaisian to Lower Visean) (1)

Province:
Iullemmeden Basin - Tim Mersoï Sub-basin

Type Locality and Naming

Valsardieu, 1971. Group: Terada Gr

References: Joulia, 1959a; Lessard, 1961; Claret & Tempère, 1968; Abdoulaziz et al., 1968; Valsardieu, 1971; Termier, 1973; Fabre et al., 1983; Conrad et al., 1986; Coquel et al., 1995; Fabre, 2005.

Synonym: "Grès et conglomérats de Teragh"; Upper sandstone Member of the Farrazekat Fm of Joulia (1959).

Equivalent(s): In Ateï Fm sandstone of Algeria

Lithology and Thickness

Conglomerates, sandstones and argillites in blocks, varved argillites and sandstones, corresponding to old moraines, transgressive on a basement shaped by ice. More to the south, away from the Niger/Algeria border (section #2 of Claret & Tempère (1968); see Fig. 7-72), these sandstones get differentiated from the “In Ateï Fm sandstones” of Algeria by greater development of the coarse material, in particular at the base of the upper cycle where one observes cones of deltaic debris containing plants at different levels. It is located at the base of the Terada Gr and represents an advanced witness of the Permo-Carboniferous glaciations of Gondwana. Thickness is 150 m.

Lithology Pattern:

Glacial till

Relationships and Distribution

Lower contact

Underlying unit is the Farrazekat Fm.

Upper contact

Overlying units are Talak Fm / Aoulingen Fm or Tim Mersoï Fm

Regional extent

GeoJSON

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Fossils

Valsardieu (1971, p. 75) and Conrad et al. (1986) describe abundant plant material (Rhacopteris, Lepidodendron, Ulodendron, Archaeosigillaria, Calamites)

Age

Lower Carboniferous (Lower Tournaisian to Lower Visean); Coquel et al., 1995. See comment under Farrazekat Fm (Figure in that entry).

Age Span:

Beginning stage:

Tournaisian

Fraction up in beginning stage:

0.0

Beginning date (Ma):

359.30

Ending stage:

Visean

Fraction up in the ending stage:

0.5

Ending date (Ma):

338.54

Depositional setting

Fluvio-deltaic/glacial to continental shelf deposits. Includes old moraines, transgressive on a basement shaped by ice

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)