Home Multi-Country Search About Admin Login


Information provided by geoscience team at Ahmadu Bello University, Zaria, Nigeria --see About

Search by
Select Region(s) to search
Hold Ctrl (Windows/Linux) or Command (Mac) to select multiple
Gara Sayada Formation
Click to display on map of the Ancient World at:
Gara Sayada Fm base reconstruction

Gara Sayada Fm

Period: 
Cambrian, Ordovician

Age Interval: 
Fortunian – Hirnantian


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 Gara Sayada is the oldest formation in the Iguidi Sub-basin. It is about 70-1000m thick, and is made up of sandstones. It is the lateral equivalent of the Ghezziane Fm of the Yetti Sub-basin (Guerrak, 1989).


Lithology Pattern: 
Sandstone


Relationships and Distribution

Lower contact

The Gara Sayada Fm rests non-conformably on the Eglab Fm of Precambrian Basement Complex

Upper contact

It is conformably overlain by the Gara Sayada Fm

Regional extent

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


GeoJSON

{"type":"Feature","geometry":{"type":"MultiPolygon","coordinates":[[[[-6.64,28.93],[-5.14,29.21],[-3.93,29.03],[-4.06,28.43],[-5.01,27.48],[-5.54,26.81],[-5.81,25.73],[-6.31,24.91],[-7.71,23.68],[-8.19,23.2],[-10.26,22.65],[-6.64,28.93]]]]}}

Fossils


Age 

Fortunian – Hirnantian (poorly dated sandstone facies)

Age Span: 

    Beginning stage: 
Fortunian

    Fraction up in beginning stage: 
0.00

    Beginning date (Ma): 
538.80

    Ending stage: 
Hirnantian

    Fraction up in the ending stage: 
1.0

    Ending date (Ma):  
443.07

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).