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Mecheri Formation
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Mecheri Fm base reconstruction

Mecheri Fm

Period: 
Devonian

Age Interval: 
Famennian


Province: 
Tindouf Basin

Type Locality and Naming

Iguidi subbasin (exposed on northeast margin of Tindouf Basin)

Synonym:

References: Guerrak, 1989

[Fig. 1: Geological map of the Tindouf Basin region. (from Guerrak, 1989).]

[Fig. 2: Location of the Tindouf Basin Province, North Africa, and the six assessment units (AUs) (USGS, 2019).]

[Fig. 3: Stratigraphic column of the Tindouf Basin region (Guerrak, 1989).]

[Fig. 4: Stratigraphic correlation of the northern and southern flanks of the Tindouf Basin (Guerrak, 1989).]

[Fig. 5: Stratigraphic column of the study area (redrawn after Guerrak, 1988a).]


Lithology and Thickness

The Mecheri Fm is about 200-250m thick and is characterised at the base by argillaceous siltstones (which is the lateral equivalent of the Oued Ghazal Fm in the Yetti Subbasin), and in the top section by silty shales (which is the lateral equivalent of the Kerb En Naga Fm in the Yetti Subbasin) (Guerrak, 1989).


Lithology Pattern: 
Siltstone


Relationships and Distribution

Lower contact

Conformably overlies the Bou Bernous Fm

Upper contact

-NA- Top section concealed (see fig. 4 of Guerrak, 1989).

Regional extent

Extend through northern and southern flanks of the Tindouf Basin; and Iguidi subbasin (exposed on northeast margin of Tindouf Basin)


GeoJSON

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Fossils


Age 

Famennian

Age Span: 

    Beginning stage: 
Famennian

    Fraction up in beginning stage: 
0.00

    Beginning date (Ma): 
371.10

    Ending stage: 
Famennian

    Fraction up in the ending stage: 
1.0

    Ending date (Ma):  
359.30

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:

Andrea Ciampalini, Francesca Garfagnoli, Benedetta Antonielli, Chiara Del Ventisette & Sandro Moretti (2012) Photo-lithological map of the southern flank of the Tindouf Basin (Western Sahara), Journal of Maps, 8:4, 453-464, DOI: 10.1080/17445647.2012.746947

Guerrak S. (1989): Time and space distribution of Palaeozoic oolitic ironstones in the Tindouf Basin, Algerian Sahara. In: Young, T. P. & Taylor, W. E. G. (eds), 1989: Phanerozoic Ironstones

Geological Society Special Publication 46, pp. 197-212

Guerrak S. (1988a): Geology of the Early Devonian oolitic iron ore of the Gara Djebilet field. Saharan Platform, Algeria. Ore Geology Reviews, (In Press).