Awaynat Wanin Formation

Awaynat Wanin Fm

Period:

Devonian

Age Interval:

Givetian - Famennian

Province:
Murzuq Basin, Ghadames Basin

Type Locality and Naming

Borghi (1939) recognized rocks of the middle Devonian age in the Awaynat Wanin area, but the name Awaynat Wanin Formation was first introduced by Lelube (1946). Bellini and Massa (1980) described a type section of 225m in the western AI Qarqaf area, appointing four units of chronostratigraphic significance (Pierobon, 1991).The Awaynat Wanin Fm. is also known as the Aouinet Uennin Fm. in the Ghadames Basin.

Synonym:

References: Borghi, 1939; Lelube, 1946; Bellini and Massa, 1980; Castro et al., 1985; Pierobon, 1991; Shalbak, 2015

Lithology and Thickness

Bellini and Massa (1980) described a type section of 225m in the western AI Qarqaf area, appointing four units of chronostratigraphic significance (Pierobon, 1991). Castro et al. (1985) reported two types of deltaic facies at outcrop: fine-grained suspension deposits (delta front) and coarse-grained traction sediments (fluvial-distributary channels), all of them intensely reworked by tide and storm waves (Pierobon, 1991). In the subsurface the formation has been cored in four wells in NC 115. These show a mud-dominant development; sandstones were present but had a generally very poor reservoir quality.

Lithology Pattern:

Clayey sandstone

Relationships and Distribution

Lower contact

It conformably overlies the Ouan Kasa Fm.

Upper contact

It is conformably overlain by the Tahara Fm, and unconformably overlain by the Marar Fm in some places (see Fig. 18 of Shalbak, 2015; Craig, 2006 as used by SEPM summary).

Regional extent

It is present in the Murzuq and Ghadames-Berkine Basins.

GeoJSON

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Fossils

Age

Onset might be in Eifelian (Craig, 2006, as used in SEPM summary), but Givetian used here. A mid-Famennian termination used here, following Craig (2006, as used in SEPM summay)

Age Span:

Beginning stage:

Givetian

Fraction up in beginning stage:

0.00

Beginning date (Ma):

385.30

Ending stage:

Famennian

Fraction up in the ending stage:

0.5

Ending date (Ma):

365.20

Depositional setting

Pierobon (1991) suggested the geological setting of the Qwaynat Wanin Formatoin was predominantly marine with fluvial deltaic deposits occuring in its middle and upper parts.

Depositional pattern:

Additional Information

Compiler:

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