Nefusa Gr
Period:
Cretaceous
Age Interval:
late Aptian – Cenomanian.
Province:
Oued Mya Basin, Ghadames Basin
Type Locality and Naming
Synonym: Nefousa Gr (USGS-Klett, 2000), Nefusa Fm
References: Bora and Dubey, 2015
Lithology and Thickness
The Nefusa Fm is made up of shales that transitions laterally into sandstone as it moves eastwards (Bora and Dubey, 2015).
Lithology Pattern:
Sandy claystone
Relationships and Distribution
Lower contact
The Nefusa Fm. unconformably overlies the Chicla Fm. (Austrian unconformity – see Fig. 2 of Bora and Dubey, 2015). Lower and Middle Aptian is absent.
Upper contact
It is conformably overlain by the Alhambra Gr.
Regional extent
It extends throughout the Oued Mya and Ghadames Basin.
GeoJSON
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Fossils
Age
Late Aptian through Cenomanian (using diagram of USGS-Klett 2000); Early and Middle Aptian is a regional hiatus.
Age Span:
Beginning stage:
Aptian
Fraction up in beginning stage:
0.8
Beginning date (Ma):
114.84
Ending stage:
Albian
Fraction up in the ending stage:
1.0
Ending date (Ma):
100.50
Depositional setting
Depositional pattern:
Additional Information
:
Compiler:
s:Enam O. Obiosio, Solomon Joshua Avong and Henry Nasir Suleiman (2024) - Stratigraphic Lexicon compiled from the following books:Bora, D., Dubey, S. (2015): New insight on petroleum system modeling of Ghadames basin, Libya. Journal of African Earth Sciences, 112: pp.111-128. http://dx.doi.org/10.1016/j.jafrearsci.2015.08.020
T.R. Klett (2000): Total Petroleum Systems of the Trias/Ghadames Province, Algeria, Tunisia, and Libya - The Tanezzuft-Oued Mya, Tanezzuft-Melrhir, and Tanezzuft-Ghadames. U.S. Geological Survey Bulletin, 2202-C.