Al Mahruqah Formation

Al Mahruqah Fm

Period:

Quaternary, Neogene

Age Interval:

early Pliocene- Pleistocene

Province:
Murzuq Basin

Type Locality and Naming

Murzuq Basin of SW Libya.

Synonym: Al Mahrūqah Fm

References:

Lithology and Thickness

Consisting of four distinct lacustrine limestone members formed during major humid Sahara episodes.

Antalkhatá Member: The oldest and often highest-magnitude widespread limestone bed.

Brak Member: Brecciated limestone units found in Wadi ash Shati.

Bi'r az Zallaf Member: Mid-sequence lacustrine carbonate deposition.

Aqar Member: The youngest and spatially most restricted limestone member.

Lithology Pattern:

Limestone

Relationships and Distribution

Lower contact

It unconformably overlies the Maul Ninah Fm, but an episode of Miocene basalts (unnamed formation?) are indicated within that interval (perhaps associated with the “Alpine unconformity” of Marzo and Ramos, 2003?).

Upper contact

Murzuq Quaternary Fm.

Regional extent

Found in the endorheic Murzuq Basin and Wadi ash Shati region of the Fezzan in southwest Libya.

GeoJSON

{"type":"Feature","geometry":{"type":"Polygon","coordinates":[[[10.976,25.209],[12.169,25.606],[13.321,26.008],[14.39,26.376],[15.419,26.748],[16.2,27.199],[16.735,26.044],[17.105,24.852],[16.982,23.663],[16.53,22.58],[15.871,21.533],[16.036,20.708],[17.023,20.089],[18.175,19.575],[19.45,19.247],[18.628,18.748],[16.776,18.604],[14.761,18.661],[12.992,18.923],[11.84,19.515],[11.223,20.335],[10.812,21.372],[10.524,22.613],[10.359,23.904],[10.976,25.209]]]}}

Fossils

Age

Shown in Fello (2001)’s Repsol regional column as Pliocene-Miocene. Google Gemini: “The classic Al Mahrūqah Formation represents Middle Pleistocene lake deposits. Broader regional studies place the broader Al Mahruqah Group's lower transitions into the late Miocene and early Pliocene.”

Age Span:

Beginning stage:

Zanclean

Fraction up in beginning stage:

0.00

Beginning date (Ma):

5.34

Ending stage:

Holocene

Fraction up in the ending stage:

0.0

Ending date (Ma):

0.01

Depositional setting

Al Mahrūqah Formation represents Middle Pleistocene lake deposits. Characterized by carbonate and lacustrine beds tied to historic paleolakes (ancestral Megafezzan systems).

Depositional pattern:

Additional Information

Compiler:

Enam O. Obiosio, Solomon Joshua Avong and Henry Nasir Suleiman (2026). The Cretaceous and Cenozoic entries were mainly taken from AI-assistant summaries of Google’s Gemini (accessed in Aug’2026)