Cenozoic

Cretaceous

Jurassic

Triassic

Permian

Paleozoic

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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Aschia-Tinamou Formation

Aschia-Tinamou Fm

Period:

Cretaceous

Age Interval:

Late Cretaceous (Late Turonian to Campanian) (7a)

Province:
East Niger Rift Basin - Termit Sub-basin

Type Locality and Naming

The Aschia Tinamou well SW of Termit Massif (Fig. 1; Fig. 2) Faure, 1966

[Figure 1: Hypothetic section showing the layers penetrated by the well at Aschia Tinamou (Faure, 1966, page 169). Green = Béréré Fm / Kandel Bouzou Fm ; Orange = Aschia-Tinamou Fm; Blue = Termit Fm]

[Figure 2: Location map of Termit Massif]

References: Faure, 1966; Fabre et al., 1983.

Synonym: Aschia Tinamou Fm. Equivalent(s): Yogou Fm & upper part of the Donga Fm in the Termit Graben

Lithology and Thickness

Green or black clays, dark shales and gray or yellow limestones. Gypsum, pyrite and fibrous calcite are abundant, as well as phosphate levels in fish debris. Faure (1966) states that the upper part of the Aschia-Tinamou Fm thickness is 170 m. On page 50, he says the whole formation is 300 m. The lower part of the Aschia-Tinamou Fm is, therefore, ~130 m.

Lithology Pattern:

Gypsiferous claystone

Relationships and Distribution

Lower contact

Underlying unit is the Béréré Fm & Kandel Bouzou Fm

Upper contact

Overlying unit is the Termit Fm

Regional extent

East Niger Rift Basin - Termit Sub-Basin - West

GeoJSON

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Fossils

The mollusc fauna is closely correlated with the Awgu Fm (Coniacian) in Nigeria. Fish, lamellibranchs, foraminifers, and ammonites (Tissotia species limited to West Africa, such as Tissotia latelobata Solger).

Age

Late Cretaceous (Late Turonian to Campanian) (Faure 1966)

Age Span:

Beginning stage:

Turonian

Fraction up in beginning stage:

0.5

Beginning date (Ma):

91.65

Ending stage:

Santonian

Fraction up in the ending stage:

1.0

Ending date (Ma):

83.65

Depositional setting

Marine

Depositional pattern:

Additional Information

There is no outcrop of the Formation. All were determined from drill holes (Fig. 1).

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)