Sedimentology and Geochemical Evaluation of Lignite-Argillite Sequences in a Named Basin in Bali Nyonga, Northwest, Cameroon

摘要: The sedimentology and geochemistry (major and trace element compositions) of lignite argillite (carbonaceous shale claystone) sequences in a Basin Bali Nyonga, west of the Bamenda Mountain have been investigated to determine their and the prevailing environmental conditions which control formation. Ten representative samples were obtained fromtrenches, pits, river stream valleys the study area. These samples ashes subsequently examined using X-ray fluorescence spectrometry (XRF), inductively coupled plasma spectrometry (ICP), X-ray diffraction analysis (XRD). geochemical results revealed that thelithophile, chalcophile siderophile elements dominantly epigenetic origin, mainly from detrital sources supported by high silica alumina concentrations all samples. The mineral phases identified quartz, kaolinite, illite, pyrite, hematite, and minor feldspars,pseudorutile. relatively (54.10 wt%) and contents (27.77 wt%) these samples can be explained input during peat low contents of MgO CaO analysed agree very much with continental setting formating basin. A clayey microband derived from alkaline volcanic was dominant composition of these microbands mixed-layer clay minerals illite kaolinte, which interlayered organic bands. modes occurrence ash bands indicated volcanic activities characterized multiple eruptions, short time interval and small scale for each eruption accumulation. ratios of redox-sensitive traceelement (V/Cr versus Ni/Co V/V + Ni Ni/Co), Sr/Ba, major oxides ratio (CaO Fe2O3)/(SiO2 + Al2O3) from the Nyonga indicate terrestrial, reductive (oxic), littoral brackish water environmental conditions which are characteristics of paludal-lacustrine basin is filled Tertiary materials.