Carb-A-B-C Formation

Carb-A-B-C Fm

Period:

Carboniferous

Age Interval:

Tournaisian – Visean.

Province:
Illizi Basin

Type Locality and Naming

“Carboniferous formations are divided into members, each having a code from A to F, with A being the oldest and F the youngest” (USGS-Klett, 2000, summary). [NOTE: For clarity and to separate from the “F2” etc. set of Devonian, then the prefix “Carb-“ is added to this Lexicon.]

Synonym: A, B, and C members (see Benvegnù, 2020).

References: Benvegnù, 2020.

Lithology and Thickness

It is characterized by a sequence of silty shales and sandstone with interbedded siltstone and limestone, and comprises a basal conglomerate (Benvegnù, 2020).

Lithology Pattern:

Sandy limestone

Relationships and Distribution

Lower contact

It conformably overlies the Carb-F2 Fm.

Upper contact

It is conformably overlain by the Carb-D-E Fm.

Regional extent

Illize Basin of SE Algeria

GeoJSON

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Fossils

Age

Lower Carboniferous

Age Span:

Beginning stage:

Tournaisian

Fraction up in beginning stage:

0.00

Beginning date (Ma):

359.30

Ending stage:

Visean

Fraction up in the ending stage:

1.0

Ending date (Ma):

330.34

Depositional setting

Fluvial-dominated deltaic in the basal parts, which becomes more wave-dominated in the uppermost part (Benvegnù, 2020).

Depositional pattern:

Additional Information

: In the Illizi area, B and C can be considered as good reservoirs members (Benvegnù, 2020).

Compiler:

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

Benvegnù I. (2020): Thermal Evolution of Paleozoic and Triassic Reservoir Rocks in the Ghadames-Illizi Basin (Algeria). An unpublished MSc thesis at Universita’ degli Studi di Padova.

T.R. Klett (2000): Province, Algeria, Tunisia, and Libya - The Tanezzuft-Oued Mya, Tanezzuft-Melrhir, and Tanezzuft-Ghadames. U.S. Geological Survey Bulletin, 2202-C.