Gangara Fm
Period:
Cretaceous
Age Interval:
Upper Cretaceous (Upper Turonian) (4)
Province:
Iullemmeden Basin - Southeast Aïr & Damergou
Type Locality and Naming
Five km NW of Gangara in Damergou. Joulia, 1951. Group: Damergou Gr
References: Chudeau, 1909; Furon, 1934; Lambert, 1943; Schneegans, 1943; Joulia, 1951; Faure, 1966, page 159; Greigert, 1966 ; Fabre et al., 1983; Mathey et al., 1991.
Equivalent(s): White Limestone Fm
Lithology and Thickness
See Damergou Gr. Non-marine clays and sandstones. Joulia (1951) provides the following section in the Damergou:
- 22 m - Greenish gray clays, finely layered. Gypsum. Calcareous nodules surrounded by fibrous calcite. Remains of Vertebrates (Onchosaurus pharao); a 15 cm glauconitic bed at the base.
- 1 m - Sandy white sandstone, fine and micaceous; Lenses of gray clay with carbonaceous debris.
- Masked by scree
- 4 m - Ferruginous sand
- 5 m - Feldspathic, pink or white sand
- 5 m - Gray clays in sheets. Gypsum. Carbonaceous debris.
- Bed of yellow lumachellic limestone of Nigericeras.
Thickness is up to 80 m.
Lithology Pattern:
Continental marl
Relationships and Distribution
Lower contact
Underlying unit is the Béréré Fm (See Damergou Gr).
Upper contact
Overlying unit is the Dambanza Fm (See Damergou Gr).
Regional extent
GeoJSON
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Fossils
vertebrates, fish
Age
Upper Cretaceous (Upper Turonian)
Age Span:
Beginning stage:
Turonian
Fraction up in beginning stage:
0.5
Beginning date (Ma):
91.65
Ending stage:
Turonian
Fraction up in the ending stage:
1.0
Ending date (Ma):
89.39
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)