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El Guettara Gr
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El Guettara Gr base reconstruction

El Guettara Gr

Period: 
Carboniferous

Age Interval: 
Tournaisian – Kasimovian


Province: 
Taoudeni Basin

Type Locality and Naming

This formation is mainly in the eastern portion (e.g., Hank sub-basin) of the Taoudeni Basin, which a vast intracratonic sedimentary basin spanning parts of Mauritania, Mali, Algeria, Burkina Faso and Guinea.

Synonym:

References: Martin-Monge et al., 2016

[Fig. 1: Location of the Taoudeni Basin Province and the four assessment units defined in the study by Brownfield et al. (2015).]

[Fig. 2: The Taoudeni Basin (Taupin et al., 2017)]

[Fig. 3: Abolag-1 well, R well and Atar Group type section stratigraphy, facies description and correlation in the Taoudeni Basin, and organic richness profile in the Abolag-1 well (Claue,1981; Rooney et al.2009; Trompette,1973; Albert-Villanueva et al. 2016).]

[Fig. 4: Generalized stratigraphy of the Taoudeni Basin in Mauritania. Lithostratigraphic name equivalences are provided for the Adrar, Hank and Hodh depocentres. The major discontinuities are numbered and reference to global glacial and tectonic events is provided. (From Martin-Monge et al. (2016) as modified after Lahondere et al. (2003, 2005).]


Lithology and Thickness

The El Guettara Group is made up of fossiliferous sandstone, limestone, and marl with brachiopods and corals (Bradley et al., 2015). It would be the lateral equivalent of the upper part of the Tenemouj Gr of the Adrar Subbasin, although it is uncertain if that upper part extends to the upper Carboniferous.


Lithology Pattern: 
Sandy limestone


Relationships and Distribution

Lower contact

Conformably overlies the In Dagouber Gr

Upper contact

Unconformably underlies the Telig Gr

Regional extent

Eastern part of the Taoudeni Basin.


GeoJSON

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Fossils

Brachiopods and corals


Age 

Martin-Monge et al. (2016) summary figure schematically indicates a span of entire Carboniferous, less the Pridoli for the overlying Tichit Fm..

Age Span: 

    Beginning stage: 
Tournaisian

    Fraction up in beginning stage: 
0.00

    Beginning date (Ma): 
359.30

    Ending stage: 
Kasimovian

    Fraction up in the ending stage: 
1.0

    Ending date (Ma):  
303.68

Depositional setting

Shallow marine


Depositional pattern:  


Additional Information


Compiler:  

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

Taylor, C. D. and Giles, S. A. (2013): Mineral Potential for Sediment-Hosted Copper Deposits in the Islamic Republic of Mauritania: Phase V, Deliverable 75. U.S. Geological Survey, Reston, Virginia

Martin-Monge, A., Baudino, R., Gairifo-Ferreira, L. M., Tocco, R., Badali, M., Ochoa, M., Haryono, S., Soriano, S., El Hafiz, N., Mez, J. H., Chacon, B., Brisson, I., Grammatico, G., Varade, R., and Abdallah, H. (2016): An unusual Proterozoic petroleum play in Western Africa: the Atar Group carbonates (Taoudeni Basin, Mauritania). In: Sabato Ceraldi, T., Hodgkinson, R. A. & Backe, G. (eds) Petroleum Geoscience of the West Africa Margin. Geological Society, London, Special Publications, 438, http://doi.org/10.1144/SP438.5

Kah, L. C., Bartley, J. K., and Stagner, A. F. (2009): Reinterpreting a Proterozoic enigma: Conophyton-Jacutophyton stromatolites of the Mesoproterozoic Atar Group, Mauritania. International Association of Sedimentologists, Special Publication, 41: pp. 277-295

Bradley, D. C., Motts, H. A., Horton, J. D., Giles, Stuart, and Taylor, C. D. (2015): Geologic Map of Mauritania (Phase V, Deliverables 51a, 51b, and 51c), Chap. A1 of Taylor, C. D., ed., Second Projet de Renforcement Institutionnel du Sector Minier de la Republique Islamique de Mauritanie (PRISM-II): U.S. Geological Survey Open-File Report 2013-1280-A1, 3 pl., http://dx.doi.org/10.3133/ofr20131280