The Campano-Maastrichtian successions in the northern Anambra Basin comprises theNkporoFormation, Mamu Formation and Ajali Sandstone.An extensive geological field work was carried out, where lithostratigraphic sections were studied and described. Features such as textures, physical and biogenic sedimentary structures (facies variations and associations) were documented. Some selected representative samples of the sedimentary depositional facies were also subjected to grain size analysis.The NkporoShale is made up ofsandy shale, silty clay, grey mud, bioturbatedsiltstone which graded into Mamu Formation which is made up ofcross-massive bedded sandstone with bioturbation structures, siltstone, dark grey to light grey fissile shale, mudstone and milky white claystone which often displays a fining upward trend. It passes upward into Ajali Sandstone which is made up of fine to coarse-grained, cross-bedded sandstone and fissile shale with bioturbation structures.The sandstone facies of the Mamu Formation is coarse to fine-grained, poorly to moderately sorted, leptokurtic and negatively skewed possibly deposited from fluvial source. The bioturbated lower sandstone beds contain burrows of Ophiomorphawhich belong to skolithosichnofacies that typifies littoral environment while the Ajali Sandstone is pebbly coarse to medium-grained, poorly to moderately sorted, predominantsmesokurtic toplatykurtic orvery platykurtic and negative to near symmetrical.The linear discriminate function scatter plots results reveal shallow marine deposits forthe sandstone facies of Mamu Formation and AjaliSandstone. The fissility of shale suggests that it was deposited in a low energy environment. However, the textural studies of the Nkporo Formation and the siltstone facies of the Mamu Formation suggests the sediments to be deposited in a low energy environment which favoured deposition of fine to medium size sediments, that is, deltaplain to prodelta environment. Field and textural studies of the sandstone facies of the Mamu Formation suggest the sediments to be deposited in a relatively high energy environment with tidal influence of transport and deposition with two main facies association, that is, subtidal and intertidal.The cross-beddings, unimodal paleocurrent of Ajali Sandstones also indicates fluvial or fluvial-dominated deltaic environment while the bimodal oblique paleocurrent pattern obtained for Mamu Formation shows that the formation was deposited in environment such as shoreline (beach) or fluvio-deltaic where tidal effect is significant.Paleocurrent studies and textural characteristics indicate that the paleocurrent direction is northeast while the provenance is southwest suggesting that the sediments were mainly sourced from the Santonian Okigwe-AbakalikiAnticlinorium and partly from the nearby Oban Massif for the Ajali Sandstone in the study area while the sediments of the sandstone facies of Mamu Formation were sourced from more than one source.The results obtained from the textural, structure and statistical analyses revealed that the sediments in the study area were deposited in fluvial, deltafront through deltaplain to prodeltain shallow marine environment.