Hydrocarbon potential, palynology and palynofacies of four sedimentary basins in the Benue Trough, northern Cameroon. (March 2018)

• Record Type: Journal Article
• Authors: Bessong, Moïse; Hell, Joseph Victor; Samankassou, Elias; Feist-Burkhardt, Susanne; Eyong, John Takem; Ngos, Simon III; Nolla, Junior Désiré; Mbesse, Cecile Olive; Adatte, Thierry; Mfoumbeng, Marie Paule; Dissombo, Edimo André Noel; Ntsama, Atangana Jacqueline; Mouloud, Bennami; Ndjeng, Emmanuel
• Is Part Of: Journal of African earth sciences. Volume 139(2018)
• Page Start: 73
• Page End: 95
• Publication Date: 2018-03
• Subjects: Yola-garoua branch -- Benue trough -- Hydrocarbon reservoirs -- Tertiary -- Cretaceous; Earth sciences -- Africa -- Periodicals; Earth sciences -- Middle East -- Periodicals; Geology -- Africa -- Periodicals; Geology -- Middle East -- Periodicals; Sciences de la terre -- Afrique -- Périodiques; Sciences de la terre -- Moyen-Orient -- Périodiques; Géologie -- Afrique -- Périodiques; Géologie -- Moyen-Orient -- Périodiques; Earth sciences; Geology; Africa; Middle East; Periodicals; Electronic journals; 556.05
• DOI: 10.1016/j.jafrearsci.2017.11.012
• Languages: English
• ISSNs: 1464-343X

Abstract

Abstract: Organic geochemical, palynological and palynofacies analyses were carried out on 79 selected samples from four sedimentary basins (Mayo-Rey, Mayo-Oulo-Lere, Hamakoussou and Benue) in northern Cameroon. Rock-Eval pyrolysis and Total Organic Carbon results indicate that most of the samples of the studied basins are thermally immature to mature. The organic matter consists of terrestrial components (peat, lignite, bituminous coal, and anthracite) associated with organic matter of marine origin. Based on the appraisal of multiple parameters: Total Organic Carbon (TOC), maximum Temperature (T-max), Hydrogen Index (HI), Oxygen Index (OI) and Production Index (PI), some samples are organically rich both in oil and/or gas-prone kerogen Type-II, II/III and III. The source rock quality ranges from poor to very good. The source material is composed of both algae and higher plants. Samples from these basins yielded palynological residue composed of translucent and opaque phytoclasts, Amorphous Organic Matter (AOM), fungal remains, algal cysts pollen and pteridophyte spores. Abundance and diversity of the palynomorphs overall low and include Monoporopollenites annulatus (= Monoporites annulatus ), indeterminate periporate pollen, indeterminate tetracolporate pollen, indeterminate tricolporate pollen, indeterminate triporate pollen, indeterminate trilete spores, Polypodiaceoisporites spp., Biporipsilonites sp., Rhizophagites sp., Striadiporites sp., Botryococcus sp. (colonial, freshwater green algae), and Chomotriletes minor (cyst of zygnematalean freshwater green algae). Age assigned confidently for all these basins the palynological data except for one sample of Hamakoussou that can be dated as Early to Mid-Cretaceous in age. Callialasporites dampieri, Classopollis spp., Eucommiidites spp. and Araucariacites australis indicate, an Aptian to Cenomanian age. The other pollen and spores recovered may indicate a Tertiary or younger age (especially Monoporopollenites annulatus ), or have arisen from modern contamination. Geochemical data show that sediments are wackes, arkose, iron-sandstone and iron-shale. The Chemical Index of Alteration (CIA-K) is low moderate to high, suggesting a shorter exposure time and fast erosion and transport. The studied sequences cover various depositional settings ranging from wetlands to dry environment inside island arc, passive margin or active continental margin. This study reveals new data and the economic potential of this part of Cameroon. Highlights: The BT is a fluvial depositional system, whereas the HB, MOLB and MRB are fluvio-lacustrine. Some samples contain almost sufficient amounts of organic matter to generate petroleum. Primary source of terrestrial material is of continental origin. HB, MOLB, MRB and BT samples can be dated Cretaceous to Tertiary in age.