In-Azaoua Fm
Period:
Cambrian, Ordovician
Age Interval:
Cambrian-Ordovician (1)
Province:
Iullemmeden Basin - Tim Mersoï Sub-basin
Type Locality and Naming
Section #1 of Claret & Tempère (1968) in Algeria (see figures with In-Azaoua Gr). Joulia (1959). Claret & Tempère (1968) make it a formation of the “Tamesna Lower Sandstones” Group (see “In-Azaoua Gr”). Group: Upper formation in the In-Azaoua Gr
References: Joulia, 1959; Claret & Tempère, 1968; Fabre et al., 1983; Abdoulaye et al., 2007
Synonym: Grès d'In Azaoua (not to confused with the Assaouas Fm of Jurassic);
Lithology Pattern:
Coarse-grained sandstone
Relationships and Distribution
Lower contact
Underlying unit is the Tindi Fm of the same In-Azaoua Gr
Upper contact
Overlain by either the “Terminal Complex” at top of the In-Azaoua Gr or the Graptolitic Shales Fm
Regional extent
GeoJSON
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Fossils
These sandstones contain a few scattered tigillites [= tube-like trace-fossil, mainly found in Ordovician]
Age
Age Span:
Beginning stage:
Sandbian
Fraction up in beginning stage:
0.0
Beginning date (Ma):
458.18
Ending stage:
Katian
Fraction up in the ending stage:
0.6
Ending date (Ma):
448.23
Depositional setting
Marine
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)