TAGS Formation

TAGS Fm

Period:

Triassic

Age Interval:

Norian – Rhaetian

Province:
Oued Mya Basin, Ghadames Basin

Type Locality and Naming

TAGS = Triassic Argilo-Greseux Superieur = Triassic Clayey Sandstone Upper

Synonym: Triassic Argilo-Greseux Superieur Fm, Gassi Touil Fm (Klett, 2000). (informal term based on facies). Gessi Touit. Bir Ghnem (Ghadames Basin? – diagram in Bora and Dubey, 2015)

References: Klett, 2000.

Lithology and Thickness

The TAGS Fm. is made up of Sandstone, mudstone, salt, and volcanic rocks (Klett, 2000).

Lithology Pattern:

Clayey sandstone

Relationships and Distribution

Lower contact

It conformably overlies the Argilo-Carbonate Fm. in the Oued Mya (or Triassic Basin), while it conformably overlies the Permian Azizia Fm. in the Chotts Basin.

Upper contact

It is conformably overlain by the Saliferous Units Fm. in the Oued Mya Basin, while it is conformably overlain by the D2/Infra D2 Fm in the Chotts Basin.

Regional extent

Northwestern Algeria to Central Tunisia.

GeoJSON

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Fossils

Age

Middle Norian-Rhaetian?

Age Span:

Beginning stage:

Norian

Fraction up in beginning stage:

0.3

Beginning date (Ma):

220.83

Ending stage:

Rhaetian

Fraction up in the ending stage:

1.0

Ending date (Ma):

201.36

Depositional setting

Depositional pattern:

Additional Information

Compiler:

Enam O. Obiosio, Solomon Joshua Avong and Henry Nasir Suleiman (2024) - Stratigraphic Lexicon compiled from the following books:

Baouche, R., Ganguli, S. S., Sen, S., Radwan A. E. (2023): Assessment of reservoir stress state and its implications for Paleozoic tight oil reservoir development in the Oued Mya Basin, northeastern Algerian Sahara. Geosystems and Geoenvironment 2: pp.1-18. https://doi.org/10.1016/j.geogeo.2022.100112

Fadila B. (2004): Reservoir Characterization and Reservoir Modeling in the Northwestern Part of Hassi Massaoud Field Algeria. A PhD thesis at the University of Hamburg, Hamburg, Germany.

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.

Kraouia et al., (2023): Ordovician–Upper Silurian–Triassic Petroleum System Assessment in the Chotts Area. In S. Khomsi and F. Roure (eds.), Geology of North Africa and the Mediterranean: Sedimentary Basins and Georesources, Regional Geology Reviews, https://doi.org/10.1007/978-3-031-18747-6_7

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