First 2D and 3D interpretative models of sedimentation in the Cretaceous Hama-koussou sedimentary basin: Litho-bio-stratigraphy and palaeoenvironment records

The Hama-Koussou Basin is one of the offset structures eastern end Benue Trough in Northern Cameroon. This sedimentary basin an asymmetrical syncline whose axis strongly shifted towards East, filled predominantly with Cretaceous deposits, has experienced at least three (3) phases sedimentation during its geological history: two (2) fluvial top and second bottom consisting conglomerate, micro-conglomerate, sandstone, sandwiching fluvio-lacustrine phase fossiliferous claystones marlstones intercalations siltstones carbonate cemented fine sandstone. Numerous including planar, oblique, cross stratifications, convolute bedding, desiccation cracks, ripple marks loadcast have been recorded. mineral assemblage dominated by quartz, plagioclase, mica microcline, accompagnied diagenetic (iron oxide, silica carbonate). Clay minerals consist kaolinite, illite chlorite/smectite. Palynofloral analysis reveals various taxa indicative a environment: These include Classopollis sp., Eucommiidites Concavisporites Cicatricosisporites sp, Araucariacites australis , Callialasporites dampieri microvelatus. occurrence microvelatus confirms age whereas determination for all other samples was uncertain due to scarcity palynomorphs. Low numbers bisaccate, grass, angiosperm pollen grains may be Cenozoic or younger age, although contamination modern pollens cannot excluded.The region volcanism represented explosive effusive phases, recorded as sills dykes. Plutonism characterized establishment intrusive granite. East-West elongation observed HSB same Mayo-Oulo-Lere Babouri Figuil basins can interpreted result tectonic event linked opening Atlantic Ocean resulting formation adjoins basins. • Hama-koussou Sedimentary deposit environment. magmatic phenomena. quartz; mica, clay fluids rich iron carbonates. Diagenetic are made interbedded Various presence age.