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Laayoune Formation
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Laayoune Fm base reconstruction

Laayoune Fm

Period: 
Paleogene, Neogene

Age Interval: 
Late Oligocene – Early Miocene


Province: 
Tarfaya Basin

Type Locality and Naming

Named after the coastal town of Laâyoune.

Synonym: Laâyoune Fm

References: Wenke, 2014

[Fig. 1. Regional crustal framework of the Moroccan Atlantic rifted-passive margin showing its three, major rifted-passive margin segments that are conjugate with eastern Canada: 1) Northern Central Atlantic; 2) Georges Bank- Tarfaya Central Atlantic, and; 3) Southern Central Atlantic (three zones modified from Nemcok et al., 2005). (Galhom, 2020).]

[Fig. 2. Schematic chrono-lithology chart from the basin to inner shelf settings of the Tarfaya Basin. (Table 6, page 110, in Wenke, 2014)

[Fig. 3. Summary chart for the Tarfaya Dakhla basin showing geologic time scale, lithostratigraphy, controlling tectonic events, and interpreted horizons (Galhom, 2020).]

[Fig. 4. Lithostratigraphy and log characteristics of the Triassic to Miocene succession at well W10, offshore Tarfaya Basin (El Jorfi et al., 2015).]


Lithology and Thickness

The Laayoune Fm is a transgressive sand following the mid-Oligocene "PAU" (Peak Atlasian Unconformity) exposure and erosion form the uplift of the Atlas range. Lowstand sand-rich at beginning of the Late Oligocene through Miocene general transgression on diagram of Wenke (2014)


Lithology Pattern: 
Clayey sandstone


Relationships and Distribution

Lower contact

It is conformably overlain by the Tah Fm

Upper contact

It unconformably overlies the Samlat Fm. The contact is the "PAU" (Peak Atlasian Unconformity) exposure and erosion form the uplift of the Atlas range with variable amount of exposure and erosion.

Regional extent

The Dhakla, Laayoune and Tarfaya Basins (TB) extend along the southern Moroccan continental shelf approximately to the town of Sidi Ifni, where a gradual transition to the Souss-Basin (SB) in the north takes place (Wenke et al., 2010).


GeoJSON

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Fossils


Age 

ca. mid-Late Oligoene through Early Miocene; with the extent of the Early/Late Oligocene unconformity depending on location from minor at seaward to major at landward (Wenke, 2014; table 6, p. 110)

Age Span: 

    Beginning stage: 
Chattian

    Fraction up in beginning stage: 
0.5

    Beginning date (Ma): 
25.16

    Ending stage: 
Burdigalian

    Fraction up in the ending stage: 
1.0

    Ending date (Ma):  
15.99

Depositional setting


Depositional pattern:  


Additional Information


Compiler:  

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

El Jorfi L., Süss M.P., Aigner T., and Mhammdi N. (2015): Triassic – Quaternary Sequence Stratigraphy of the Tarfaya Basin (Moroccan Atlantic): Structural Evolution, Eustasy and Sedimentation. Journal of Petroleum Geology, 38(1), pp. 77-98.

Ghassal B.I., Littke R., Sachse V., Sindern S., Schwarzbauer J. (2016): Depositional environment and source rock potential of Cenomanian and Turonian sedimentary rocks of the Tarfaya Basin, Southwest Morocco. Geologica Acta, 14(4), pp. 419-441.

Wenke A. A. O. (2014): Sequence stratigraphy and basin analysis of the Meso- to Cenozoic Tarfaya- Laâyoune Basins, on- and offshore Morocco. PhD Thesis at Naturwissenschaftlich-Mathematischen Gesamtfakultät der Ruprecht-Karls-Universität Heidelberg.