The sedimentary successions in parts of the northern Anambra Basin have been analysed for palynomorphs. The Mamu and Ajali Formations are the exposed stratigraphic succession found in this part of the basin. Samples from these exposures were analysed for palynomorphs and lithofacies interpretations using bivariate plots for the data from granulometric analysis. The Mamu Formation of this part of the basin shows evidence of Cleistosphaeridium cf., Leptolepidite major, Triporites sp. Lycopodiacidites asperarus, Rettricolporites cf., Milforda sp., these are palynofacies mostly associated with continental environment, lots of plant cuticles and megaspores are also found in this part of the basin all pointing to continental environment of deposition. The main trends in the sequence of terrestrially derived palynofloras compare well with those known from other areas of the Cretaceous Africa. Results from the binary plots of the sandstone facies of the Ajali Formation of this part of the basin interpolating the skewness versus the standard deviation and the plots of mean versus the standard deviation and the skewness against the mean all shows evidences of fluvial system of deposition. Granulometric analysis shows very coarse to medium grained, poorly to moderately sorted, finely skewed to negatively skewed and platykurtic to leptokurtic results.
Key words: Palynomorphs, lithofacies, granulometric, Ajali Formation, Mamu Formation northern Anambra Basin
|
