Binem Formation

Binem Fm

Period:

Devonian

Age Interval:

Eifelian – Famennian

Province:
Al Kufrah Basin

Type Locality and Naming

“Vittimberga & Cardello (1963) described the Binem Formation as a sequence of Devonian feldspathic sandstones and siltstones in the Jabal Dohone in the Tibesti area in southeastern Libya. … Bellini & Massa (1980) selected the type section at the Wadi Binem-Oudi Ounga in the Tibesti area” (Tawadros, 2011, Geology of North Africa). Reference sections at Jabal ‘Asba and Jabal az Zalmah (Gindre et al., 2012).

Southeast Libya (also in the Northwestern Chad and Northeastern Sudan where this part of the Al Kufrah Basin is known as Erdis and Mourdi basins, respectively).

Synonym:

References: Sherif and Shagroni, 2008; Le Heron and Heron, 2011; Gindre et al., 2012

Lithology and Thickness

The Binem Formation is about 300m thick (Le Heron and Howard, 2011), and mostly consists of massive planar to trough cross bedded, poorly sorted, fine to coarse grained sandstones with locally some basal conglomerate lenses (Gindre et al., 2012). Sherif and Shagroni (2008) separate the Devonian sandstones into two different formations based on the presence of either Skolithos (Qardabah formation) or Zoophycos (Blitah formation).

Lithology Pattern:

Clayey sandstone

Relationships and Distribution

Lower contact

It unconformably overlies the Tadrart Fm (the contact is sometimes marked by sparse ferruginous nodules forming a cemented horizon – Gindre et al., 2012)

Upper contact

It is conformably overlain by the Dalma Fm. (Le Heron et al., 2009).

Regional extent

Only the Al Kufrah Basin.

GeoJSON

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Fossils

Skolithos sp., Zoophycos sp., pelecypods, brachiopods and gastropods. Contains palynology assemblages of Couvinian age (zone 4), early Givetian (zone 5) late Couvinian (zone 6), Frasnian (zones 7 and 8) and Early Famennian (zone 9) [See details in Tawandros, 2011, Geology of North Africa, pages 313-314].

Age

Craig (2006, used in SEPM summary) indicates Eifelian to late Famennian, followed by a gap extending from late Famennian through mid-Tournaisian.

Age Span:

Beginning stage:

Eifelian

Fraction up in beginning stage:

0.00

Beginning date (Ma):

394.30

Ending stage:

Famennian

Fraction up in the ending stage:

0.75

Ending date (Ma):

362.25

Depositional setting

Shallow marine depositional environment (Le Heron et al., 2009).

Depositional pattern:

Additional Information

Compiler:

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

Tawadros, 2011, Geology of North Africa (book).

Gindre L., Heron D. L., Bjørnseth H. M. (2012). High resolution facies analysis and sequence stratigraphy of the Siluro-Devonian succession of Al Kufrah basin (SE Libya), Journal of African Earth Sciences, 76, pp.8–26.

Schmeider, M., Buchner, E., Le Heron, D. P. (2009): The Jebel Hadid Structure (Al Kufrah Basin, SE Libya) – A Possible Impact Structure and Potential Hydrocarbon Trap? Marine and Petroleum Geology, 26, pp.310-318.