Source-Rock Potential and Paleoenvironment of the Coniacian Numanha Formation, Northeastern Nigeria: An Integrated Palynofacies and Geochemical Approach


A study of source-rock characterization and paleoenvironmental interpretation has been carried out on a relatively thick Coniacian sedimentary succession from the Numanha Formation in the Guyuk area of the Yola arm in the Northern Benue Trough, northeastern Nigeria. The aim is to provide organic facies data for the assessment of its hydrocarbon generating potential owing to the high prospects of its lateral equivalent Fika Shale in the Gongola arm of the Northern Benue Trough. The investigation of 98 samples from three outcrop sections [09° 50′ N, 11° 51′ E; 09° 54′ N, 11° 50′ E; 09° 54′ N, 11° 49′ E] which includes palynofacies analysis, spore/pollen coloration, and geochemical analyses enabled an evaluation of organic matter richness and quality. Measured TOC ranges between 0.01 and 7.4% which reflects poor to good organic richness, while visual kerogen characterization shows thermally mature Type II-III kerogen indicative of oil and gas prone materials. Recovered palynomorphs comprised both marine (dinoflagellate cysts, microforaminiferal test linings) and terrestrial (spores, pollen, freshwater alga Pediastrum) taxa. These palynomorphs vary in proportion at different horizons of the sections indicating shoreline fluctuations. Except for the Kurnyi section, amorphous organic matter occurs in minor percentages, indicating low preservation potential during deposition. All data indicate that the Numanha Formation was deposited in a highly proximal to mud-dominated oxic shelf environment.


Geosciences and Geological and Petroleum Engineering


Missouri University of Science and Technology, Grant None

Keywords and Phrases

Cretaceous; Numanha Formation; Paleoenvironment; Palynofacies; Yola Arm

International Standard Serial Number (ISSN)

1879-1956; 1464-343X

Document Type

Article - Journal

Document Version


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© 2023 Elsevier, All rights reserved.

Publication Date

01 Feb 2023