Surfah Formation

Surfah Fm

Period:

Paleogene

Age Interval:

Thanetian

Province:
Murzuq Basin, Sirte Basin

Type Locality and Naming

Synonym: Often spelled as Shurfah Fm.

References:

Lithology and Thickness

“Composed predominantly of shallow-marine carbonates, dolomitic limestones, marls, and chalky limestones.

Key Members: Divided locally in outcrops (such as along the Jabal Waddan escarpment and Al Hamada al Hamra region) into distinct members representing shifting depositional environments:

Bú Rá's Member (lower): Low-energy subtidal shallow water with green algae.

Qaltah and Ammúr Members (middle to upper): Open-shelf, warm-water habitats transitioning to neritic limestones at the top.”

Lithology Pattern:

Dolomitic limestone

Relationships and Distribution

Lower contact

Rests on formations such as the Zmam Fm (Ziman Fm) (Upper Cretaceous to Paleocene).

Upper contact

Unconformably overlain by the Bishima Fm or the Al Jir Fm, which marks the onset of the Lower Eocene sedimentary cycle. The contact boundary between the top of the Surfah Formation and the Lower Eocene strata is widely erosional.

Regional extent

Along northwest escarpments (such as Jabal Waddan) and parts of the Sirte Basin, the Shurfah Formation represents an initial regressive-transgressive Paleocene cycle. [GeoJSON is only Murzuq Basin, because Sirte Basin has other detailed age units during this same time span.]

GeoJSON

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Fossils

Age

Shown in Fello (2001)’s Repsol regional column as Paleocene. Google Gemini narrows t just Thanetian (used here)

Age Span:

Beginning stage:

Thanetian

Fraction up in beginning stage:

0.00

Beginning date (Ma):

59.24

Ending stage:

Thanetian

Fraction up in the ending stage:

1.0

Ending date (Ma):

56.00

Depositional setting

Low-energy subtidal shallow water with green algae (lower unit) followed by open-shelf, warm-water habitats transitioning to neritic limestones at the top.”

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)