Benghazi Formation

Benghazi Fm

Period:

Neogene

Age Interval:

Langhian (including pair of Serravallian-Tortonian subunits)

Province:
Cyrenaica Basin

Type Locality and Naming

Used here for the middle Miocene set of Benghazi Fm (Langhian-lowermost Serravallian), Al Sceleidima Fm (upper Serravallian), and Msus Fm (middle Tortonian),

Synonym:

References: Shaltami, O.R., et al. (2020), and Google Gemina (Aug’26)

Lithology and Thickness

It consists of open-marine skeletal packstones, coral-reef boundstones, and fossiliferous rhodolith (red algae) beds.

Lithology Pattern:

Reef limestone

Relationships and Distribution

Lower contact

Unconformable onto the Jardinah Fm, which is the basal transgressive unit of the Ar Rajmah Gr according to Shaltami et al. (2020).

Upper contact

Unconformable below the Wadi Al Qattarah Fm set (Messinian age cluster) of the Ar Rajmah Gr.

Regional extent

GeoJSON

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Fossils

Shallow-marine and platform types.

Age

Langhian (including pair of Serravallian-Tortonian subunits). [For graphic and paleogeographic purposes, the unconformities between the units and the upper-Tortonian one are not included, but the basal and uppermost are shown on the stratigraphic column.]

Age Span:

Beginning stage:

Langhian

Fraction up in beginning stage:

0.0

Beginning date (Ma):

15.99

Ending stage:

Tortonian

Fraction up in the ending stage:

1.0

Ending date (Ma):

7.25

Depositional setting

Carbonate ramp platform.

Depositional pattern:

Additional Information

Extensive outcrops of the group (especially south and east of Benghazi) serve as key field analogs for complex ooid-grainstone and microbial carbonate hydrocarbon reservoirs across the North African subsurface

Compiler:

Shaltami, O.R., et al. (2020). Petroleum system of the Cyrenaica Basin – A review. In: 1^st International Symposium on Geosciences (ISG2020), 21th March 2020, Proceeding Book: published by BR Petrobras. P. 64-71.

Tawadros, E.E. (2011). Geology of North Africa. CRC Press (Taylor & Francis Group), 931 pp.

Google Gemini (Aug 2026) – assembled synthesis of Cyrenaica Basin units from various web-accessible publications.

El Oshebi, F.M., Fares, F.F. (2026). Stratigraphy, facies, and depositional environments of the Eocene sequence in the Ras Al Hilal area, Cyrenaica, Libya. Arabian Jour. Geosciences, 19:79. https://doi.org/10.1007/s12517-026-12488-2.

El-Hawat, A.S., Abdulsamad, E.O. (2004) Geology and Archeology of Cyrenaica, Northeastern Libya. Field trip guide B01, 32^nd International Geological Congress. 36 pp.