Lokoja Fm
Period:
Cretaceous
Age Interval:
Early – Mid Campanian
Province:
Bida Basin- South
Type Locality and Naming
the type section is located in a stream channel south of the Agbaja Plateau (Whiteman, 1982)
Synonym: Lokoja Series (Falconer, 1911); Lokoja Sandstone Fm
Reference section: Reyment,1965; Adeleye,1975; Dessauvagie, 1975; Kogbe, 1976; Petters, 1978; Offodile, 1980; Whiteman, 1982; Benkhelil,1989; Okosun, 1992; Guiraud, 1993; Akande et al., 1998; Zaborski et al., 1998; Jauro et al., 2007; Obaje, 2009; Nwajide, 2013
[Fig. 1 Stratigraphic successions in the Mid-Niger Basin (also known as Bida or Nupe Basin)]
Lithology and Thickness
the formation is composed of coarse, pebbly and clayey cross-bedded sandstones and a few thin oolitic ironstones and a poorly basal conglomerate. The thickness ranges from 100-300m depending on the depth to the basement (Nwajide, 2013). Bairde (1992b) recognized three distinct facies as components of the Lokoja Fm – alluvial fans facies, flood basin and lacustrine facies, and deltaic facies.
Lithology Pattern:
Coarse-grained sandstone
Relationships and Distribution
Lower contact
Unconformably resting on the Basement Complex (Nwajide, 2013)
Upper contact
Lies beneath the Patti Fm
Regional extent
Southern Bida Basin
GeoJSON
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Fossils
Leaf impressions, Foraminifera (Ammobaculitesplummerae, Spirosplectaminahausarum, Ammomarginulina emir, Ammobaculitescoprolithiforme, Milliaminapetila, M. telemaquensis, Pseudobolivinavariana, Textulariasp., Reophaxminuta, R. guineana, Ammodiscussp.)
Age
Late Cretaceous (late Campanian; begins with mid-Campanian transgression)
Age Span:
Beginning stage:
Campanian
Fraction up in beginning stage:
0.3
Beginning date (Ma):
80.21
Ending stage:
Campanian
Fraction up in the ending stage:
1.0
Ending date (Ma):
72.17
Depositional setting
Fluvial-palludal setting with increasing marine conditions northwards (Idowu and Enu, 1992). Alluvial – floodplain and lacustrine – deltaic facies (Nwajide, 2013)
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.