Cenozoic

Cretaceous

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Gundumi Formation

Gundumi Fm

Period:

Cretaceous

Age Interval:

Upper Cretaceous pre-Maastrichtian

Province:
Sokoto Basin (S. Iullemmeden Basin)

Type Locality and Naming

Continental Intercalaire Gr of continental sediments consists the Illo Fm and Gundumi Fm in the Sokoto sub-basin. The type locality is exposed at Duts in Dambo. The Illo Formation is a lateral equivalent of the Gundumi Fm.

Reference section:Reyment,1965; Adeleye,1975; Kogbe,1976; Dessauvagie, 1975; Petters, 1978; Offodile, 1980; Whiteman, 1982; Benkhelil,1989; Okosun, 1992; Guiraud, 1993; Akandeet al., 1998; Zaborski et al., 1998; Jauroet al., 2007; Obaje,2009; Nwajide, 2013

[Fig. 1. Stratigraphic successions in the Nigerian sector of the lullummeden Basin (Sokoto Basin)]

Lithology and Thickness

Gundumi Fm is the lateral equivalent of the Illo Fm north northeast of its outcrop and it consists of a basal conglomerate that grades upwards into coarse and pebbly sandstone, mudstone, clayey sandstone, claystone and sandstone, the top of which is intensely lateritized. The Gundumi Fm lies unconformably on the basement and consists of basal conglomerates, and gravels with sand and variegated clays increasing upwards; the maximum thickness is about 350 m. The contact of the Gundumi Fm with the basement is conglomeratic. At Kona Rolga, on the Sokoto-Gusau road, a good exposure of the basal conglomerates occurs at about 11 km north of Talata Mafara where the basement outcrops. These conglomerates outcrop for hundreds of square kilometres, with large, well-rounded pebbles in a massive clayey feldspathic and ferruginous matrix. The pebble conglomerates occur also abundantly around Tureta.

Lithology Pattern:

Sandstone

Relationships and Distribution

Lower contact

Non-conformably overlies the Basement Complex. The Gundumi Fm lies unconformably on the basement with a basal conglomerate.

Upper contact

Unconformably underlies the Rima Gr (Taloka Fm). Deposition was terminated by the Maastrichtian transgression.

Regional extent

Iullemmeden Basin

GeoJSON

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Fossils

Group contains Plant fossils, freshwater invertebrates, such as mollusks

Age

Late Cretaceous (only indicated as “Pre-Maastrichtian”; with Turonian-Campanian span implied by the Geology and Mineral Resources of Nigeria, for graphic purposes, Gundumi Fm arbitrarily placed here as spanning the Turonian-Santonian with the coeval Illu Fm as Campanian)

Age Span:

Beginning stage:

Turonian

Fraction up in beginning stage:

0.0

Beginning date (Ma):

93.90

Ending stage:

Santonian

Fraction up in the ending stage:

1.0

Ending date (Ma):

83.65

Depositional setting

Continental – Alluvial to lacustrine (Nwajide, 2013). The “Continental Intercalaire” is important in Africa, it can facilitate the unity of facies, flora and fauna, which showed a uniform climate over large parts of Africa, and the change from the Jurassic to Cretaceous. The Karoo Series (Karoo Gr) of South Africa can be correlated with the upper beds of the lower portion of the “Continental Intercalaire” (Furon, 1960). The “Continental Intercalaire” corresponds to the upper part of the Nubian Sandstone, which, in the Arabo-Nubian shield, is a generalized term that begins at the base of the Paleozoic.

Depositional pattern:

Additional Information

Compiler:

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

Nigeria: Its Petroleum Geology, Resources and Potential, by Arthur Whiteman, 1982; (Volume 1) Published by Graham and Trotman Ltd.

A review of the Cretaceous System in Nigeria by P. M. Zaborski (1998) In Africa Geoscience Review, Vol.5, No.4, pp385-483

Geology and Mineral Resources of Nigeria by Nuhu George Obaje, Published by Springer-Verlag Berlin Heidelberg 2009; http://www.springer.com/series/772

Geology of Nigeria Sedimentary Basins, Nwajide C. S., 2013; Published by CSS Bookshops Limited, Lagos Nigeria.