Nubian Sandstone Formation

Nubian Sandstone Fm

Period:

Jurassic, Cretaceous

Age Interval:

Upper Jurassic – Lower Cretaceous (Oxfordian?-Aptian?).

Province:
Sirte Basin

Type Locality and Naming

“This formation is very important in the Sirt Basin, where it forms the principal petroleum reservoir in the giant oil fields of the Southeastern part of the Sirt Basin. This formation is a significant reservoir target with major fields such as the Sarir (5 billion barrels recoverable oil I hydrocarbons) and Messla Fields (3 billion barrels recoverable oil I hydrocarbons).

The term "Nubian Sandstone" is used in North Africa for a thick package of clastic dominated sediments spanning an interval from the Paleozoic in Egypt to Early Cretaceous in Libya. The Nubian Sandstone Fm is a well-defined and widespread stratigraphic unit, which can only be recognized from subsurface wells in the Sirt Basin.” (Abugares, 2007). [See Nubian Sandstone Gr for details on the nomenclature and challenges in correlating.]

Synonym: In Libya, some of the oil companies prefer to use the term 'Sarir Sandstone' (Sarir Sandstone Fm; Sarir Fm). Also known as the Nubian Sandstone, or Nubian Fm. (Abugares, 2007).

References: Abugares, 2007

Lithology and Thickness

The Nubian Sandstone is composed of a variety of interbedded non-marine lithofacies including sandstones, siltstones, shales and conglomerates. The sandstones are very fine to coarse grained quartzite, tan to grey in colour and poorly to moderately sorted, with a clay matrix and very porous. The Nubian Sandstone consists of three members; Upper sandstone, Middle shale and Lower sandstone. It reaches a maximum thickness of 1200 m in the Hameimat Trough; but potentially is in excess of 5 km in other troughs of the Sirte Basin (Abugares, 2007).

Lithology Pattern:

Sandstone

Relationships and Distribution

Lower contact

The Hercynian unconformity separates the Nubian Sandstone from the underlying granite, metamorphic and Camro-Ordovician basement (Abugares, 2007). It unconformably overlies the Hofra Fm.

Upper contact

It is unconformably overlain by the Bahi Fm.

Regional extent

GeoJSON

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Fossils

Age

Vague assignment as Upper Jurassic-Lower Cretaceous in the Sirte Basin

Age Span:

Beginning stage:

Oxfordian

Fraction up in beginning stage:

0.00

Beginning date (Ma):

161.53

Ending stage:

Aptian

Fraction up in the ending stage:

1.0

Ending date (Ma):

113.20

Depositional setting

Depositional pattern:

Additional Information

Compiler:

T. S. Ahlbrandt (2001): The Sirte Basin Province of Libya—Sirte-Zelten Total Petroleum System, U.S. Geological Survey Bulletin 2202–F

R.C. Selley (1997): The Sirte Basin of Libya. In: African Basins. Sedimentary Basins of the World, 3, edited by R.C. Selley (Series Editor: K.J. Hsu), Elsevier Science B.V., Amsterdam, pp. 27-37.

Abugares, Miloud M. (2007): Deposition, Diagenesis, and Reservoir Development of the Cretaceous Lidam Formation, SE Sirt Basin, Libya. Durham e-Theses. http://etheses.dur.ac.uk/2599/

Elkanouni, I. E. D. (2014). Sedimentology, Sequence stratigraphy and Spatial-temporal Patterns of the late Paleocene Succession, western Sirt Basin, Libya, Durham e Theses. http://etheses.dur.ac.uk/10538/