Cenozoic

Mesozoic

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Doba Formation

Doba Fm

Period:

Cretaceous

Age Interval:

Early Albian

Province:
Chad S

Type Locality and Naming

Doba Basin and Doseo Basin. The Southern Chad Basin (consists of the Bongor, Doseo, Doba, and Salamat basins)

References: Lenhardt et al., 2025; Dou et al., 2022

[Fig. 1: Simplified map of the West and Central African Rift System showing the major basins (from Lenhardt et al., 2025).]

[Fig. 2: Stratigraphy of the basins of the Central African Rift System (from Lenhardt et al., 2025)]

[Fig. 3: Composite stratigraphic column of the Doseo Basin. R_t– resistivity; GR – natural gamma (Fig 4. of Dou et al., 2022)]

[Fig. 4: Comprehensive column of sedimentary strata in the Doseo Basin of the Southern Chad Basin (from Hong et al., 2024)]

Lithology and Thickness

The Doba Fm is made up predominantly of shales, with a few thin beds of sandstone (Fig. 9 of Lenhardt et al., 2025). The thickness of the Doba Fm is 400–700 m, and the sand-to-formation ratio is about 20%–35% (Dou et al., 2022). With continuing lake transgression and limited sediment supply, thick-bedded shale predominated in the early phases of Doba Formation deposition, which occurred on top of an unconformity (Lenhaedt et al., 2025).

Lithology Pattern:

Sandy claystone

Relationships and Distribution

Lower contact

Rests conformably on the Kedeni Fm,

Upper contact

Koumra Fm, unconformably

Regional extent

Doba Basin and Doseo Basin, Southern Chad

GeoJSON

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Fossils

Age

Early Albian

Age Span:

Beginning stage:

Albian

Fraction up in beginning stage:

0.00

Beginning date (Ma):

113.20

Ending stage:

Albian

Fraction up in the ending stage:

0.5

Ending date (Ma):

106.85

Depositional setting

Lacustrine-fluvial-delta sandstone and mudstone in a highstand systems tract (Dou et al., 2022). Lacustrine to fluvial-delta sandstones and mudstones (Gao et al., 2023).

Depositional pattern:

Additional Information

Compiler:

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

Lenhardt, N., Omietimi, E. J., Edegbai, A. J., Schwark, L., Catuneanu, O., Fairhead, J. D., Gotz, A. E. (2025): Traversing the rift: A review of the evolution of the West and Central African Rift System and its economic potential. Earth-Science Reviews, 261: pp. 1-39

Dou L.. Xiao K., Du Y., Wang L., Zhang X., Cheng D., Hu Y. (2022): Exploration discovery and hydrocarbon accumulation characteristics of the Doseo strike-slip and inverted basin, Chad. Petroleum Exploration and Development, 49 (2): pp.247-256.