Mangara Gr

Cenozoic

Mesozoic

Information provided by geoscience team at Ahmadu Bello University, Zaria, Nigeria --see About

Mangara Gr

Period:

Cretaceous

Age Interval:

Barremian

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 Mangara Fm is made up of sandstone and shales intercalation of almost equal thinness (Fig. 9 of Lenhardt et al., 2025). The 1–3 km-thick Mangara Group (Barremian?) contains lacustrine mudstone and fluvial-deltaic sandstones and was formed during a complete transgressive-regressive cycle in the early stage of rifting (Dou et al., 2022b; Gao et al., 2023; Zhang et al., 2024a). Drilling data was used to conclude that the mudstones in the upper part of the Mangara Gr is relatively thin and only acts as local caprock (Dou et al., 2022). The upper sand-to-formation ratio is about 45%–60%, whereas the lower part has not been drilled yet (Dou et al., 2022).

Lithology Pattern:

Clayey sandstone

Relationships and Distribution

Lower contact

Basement Complex, unconformably

Upper contact

Lower Kedeni Fm, unconformably

Regional extent

Doba Basin and Doseo Basin, Southern Chad

GeoJSON

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Fossils

Pollen, Dinoflagellates and Cypridea

Age

Age Span:

Beginning stage:

Barremian

Fraction up in beginning stage:

0.00

Beginning date (Ma):

126.50

Ending stage:

Barremian

Fraction up in the ending stage:

1.0

Ending date (Ma):

121.40

Depositional setting

Lacustrine delta (Dou et al., 2022).

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.