[01] Aja A. U., Department of Geology, Ebonyi State University, Abakaliki, Nigeria. [02] Igwe E. O., Department of Geology, Ebonyi State University, Abakaliki, Nigeria.

Amangwu-Edda, lies within the Afikpo Sub-Basin, a sedimentary basin set up during the late Cretaceous period following the Santonian uplift in the southern Benue Trough. Local stratigraphy and field relationship show that the lithologic succession consists of black to dark grey, fossiliferous and gypsiferous shales with subordinate limestone lenses and siltstone. Palynological analysis of the shale samples collected from the surface outcrops in the area yielded a total of 117 palynomorphs, made of 24 pollen species, 9 spore species and 19 dinoflagellate species, while foraminifera biostratigraphic analysis yielded 68 forams. The abundance of the pollen species of Longapertites sp., Monosulcites sp., and Monocolpites marginatus, the spore species of Cyathidites minor, Laevigatosporites sp., along with the dinoflagellate cysts species of Leoisphaeridia sp, Andallusiella sp., and Senegalinium sp, and especially a high abundance of the foraminifera species Bolivina anambra, suggest a nearly late Campanian to Maastrichtian age for the sediments. Based on the distribution of the palynomorph species recovered from the shale samples, the study area has been interpreted as an open marine to estuarine environment at the time of sediment deposition occurring during a period of marine incursion.

Nkporo Shale, Biostratigraphy, Palynology, Foraminifera

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