Yolde Fm
Type Locality and Naming
Typical localities of the Yolde Formation are found along the valley of Pantami River in Gombe town and in the village of Yolde, 50 km to Numan town (Obaje, 2009). [Note: Below the Bornu sub-basin of Chad Basin, this unit is included in an upward extension of the sandstones of the Bima Fm.
References: Carter et al., 1963; Reyment, 1965; Cratchley and Jones, 1965;
Adeleye,1975; Kogbe,1976; Dessauvagie, 1975; Petters, 1978; Offodile, 1980; Benkhelil,1989; Guiraud, 1993; Akandeet al., 1998; Jauroet al., 2007
[Fig 1. Stratigraphic successions in the Benue Trough and the Nigerian sector of the Chad Basin]
Lithology and Thickness
The Yolde Formation was deposited under a transitional/coastal marine environment and is made up of sandstones, limestones, shales, clays and claystones. This formation consists of a variable sequence of sandstones and shales. The sandstones are thin-bedded at the base and followed by alternations of sandy mudstones and shelly limestones. Thickness: Ranges from 200 to 300 meters
Relationships and Distribution
Lower contact
Upper contact
Gongila Fm and Pindiga Fm lie conformably on the Yolde Fm in Gongola Arm, and Dukul Fm limestones overlie conformably in the Yola Arm.
Regional extent
GeoJSON
Fossils
Age
Depositional setting
Additional Information
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.