Cenozoic

Mesozoic

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T2 Formation

T2 Fm

Period:

Paleogene, Neogene

Age Interval:

Chattian – Recent

Province:
Chad S

Type Locality and Naming

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

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

[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

According to fig. 4 of Dou et al. (2022), the T2 Fm is about 100 – 200 m thick and is predominantly made up of sandstones with minor mudstones.

Lithology Pattern:

Sandstone

Relationships and Distribution

Lower contact

Rests unconformably on the T1 Fm

Upper contact

Regional extent

South Chad, Doseo Basin

GeoJSON

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Fossils

Age

Chattian – Recent

Age Span:

Beginning stage:

Chattian

Fraction up in beginning stage:

0.00

Beginning date (Ma):

27.29

Ending stage:

Holocene

Fraction up in the ending stage:

1.0

Ending date (Ma):

0.00

Depositional setting

Shore-shallow lake as well as alluvial plain (Dou et al., 2022)

Depositional pattern:

Additional Information

Compiler:

Enam O. Obiosio, Solomon Joshua Avong and Henry Nasir Suleiman (2025) - Stratigraphic Lexicon compiled from the following articles:

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.