Hawaz Fm
Period:
Ordovician
Age Interval:
Darriwilian-Sandbian
Province:
Murzuq Basin, Ghadames Basin, Al Kufrah Basin
Type Locality and Naming
The Hawaz Fm was named by Massa and Collomb (1960) after Jabal Hawaz (West of Jabal Qarqaf). Type locality: Jabal Hawaz, West of Jabal al Qarqaf (Alkhalas, 2006). It is also called Haouaz Fm (Le Heron et al., 2009).
Synonym: Haouaz Fm (Craig, 2006; used in SEPM and a Al Kufrah Basin publication)
References: Fello, 2001; Aziz, 2000; Alkhalas, 2006; Le Heron et al., 2009.
Lithology and Thickness
It consists of fine to medium-grained, coarsening-upward, well-cemented, hard sandstone, with siltstone, mudstone and fine sandy interbeds. The Hawaz Formation is very similar to the upper parts of the Hasawnah Fm, and the contact between the two units can be difficult to establish (Aziz, 2000; Alkhalas, 2006). The formation ranges from 50m (Dur al qussah) to 280m (AI Qarqaf) in thickness at outcrop (Alkhalas, 2006).
Lithology Pattern:
Clayey sandstone
Relationships and Distribution
Lower contact
It conformably overlies the Ash Shabiyat Fm in the Murzuq Basin, but conformably overlies the Hasawnah Fm. in the Ghadames and Al Kufrah Basins.
Upper contact
It is unconformably overlain by the Melez Shuqran Fm (Ordovician glaciation) in the Murzuq Basin, and unconformably overlain by the Mamuniyat Fm. in the Al Kufrah Basin.
Regional extent
It is present in the Ghadames and Murzuq Basins.
GeoJSON
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Fossils
Age
“The Hawaz succession was deposited during Darriwilian to Sandbian Stages of the Middle Ordovician.” [Gil-Ortiz, M., McDougall, N.D., et al., 2021: Sedimentary architecture of the Middle Ordovician Hawaz Formation in the Murzuq Basin (Libya). At: 35th IAS Meeting of Sedimentology (Prague))
Age Span:
Beginning stage:
Darriwilian
Fraction up in beginning stage:
0.00
Beginning date (Ma):
469.42
Ending stage:
Sandbian
Fraction up in the ending stage:
1.0
Ending date (Ma):
452.75
Depositional setting
The Hawaz Fm represents the onset of-the first major Paleozoic marine transgression in the area (Echikh and Sola, 2000). A probable transitional to a shallow marine (foreshore to shoreface) depositional setting, comparable with the present "offshore tidal sands" (shoal massifs) of the continental shelves of northern Brazil, the North Sea and the Yellow Sea (Pierobon, 1991).
Depositional pattern:
Additional Information
Compiler:
Enam O. Obiosio, Solomon Joshua Avong and Henry Nasir Suleiman (2024) - Stratigraphic Lexicon compiled from the following books: