Marar Fm
Period:
Carboniferous
Age Interval:
Visean – Serpukhovian
Province:
Murzuq Basin, Ghadames Basin
Type Locality and Naming
The Marar Formation was first defined by Lelubre in 1948 by reference to a type section at Qararat Marar northwest of the AI Qarqaf Arc.
Synonym: Mrar Fm (used in some Ghadames Basin strat columns); M’rat (Craig, 2006; used in SEPM summary)
References: Aziz, 2000; Hallett, 2002; Shalbak, 2015
Lithology and Thickness
At the type location the Marar Formation comprises about fifty stacked cycles of silty claystones, micaceous siltstones and feldspathic quartz-sandstones. The claystones are greenishgrey, silty and gypsiferous, and the sandstones and siltstones ferruginous, flaggy and often ripple-marked. The sandstones are sometimes conglomeratic at the base, frequently cross-bedded and contain brachiopods and pelecypods (Hallett, 2002). The shales are frequently silty, micaceous and pyritic, compact, dark gray to blackish in colour, while the sandstone is light gray, fine to very fine-grained and poorly consolidated by siliceous, clay or sometimes carbonate cement. Occasionally, thin shaly limestone beds also occur. The formation becomes increasingly sandy upwards (Aziz, 2000).
Lithology Pattern:
Clayey sandstone
Relationships and Distribution
Lower contact
It unconformably overlies the Tahara Fm, and sometimes underlain by the Awaynat Wanin Fm (see Fig. 18 of Shalbak, 2015).
Upper contact
It is conformably overlain by the Assedjefar Fm.
Regional extent
It is present in the Murzuq and Ghadames Basins.
GeoJSON
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Fossils
Brachiopods and pelecypods.
Age
Age Span:
Beginning stage:
Visean
Fraction up in beginning stage:
0.00
Beginning date (Ma):
346.73
Ending stage:
Serpukhovian
Fraction up in the ending stage:
0.00
Ending date (Ma):
330.34
Depositional setting
Depositional pattern:
Additional Information
Compiler:
Enam O. Obiosio, Solomon Joshua Avong and Henry Nasir Suleiman (2024) - Stratigraphic Lexicon compiled from the following books: