Savanna Journal of Basic and Applied Sciences 2(1):66-73
Biostratigraphy and Paleoenvironment of Amansiodo-1 well, Anambra Basin, Nigeria
Kovona M. T., Obiosio E.O., Najime T., Hamidu I., Nwaejije E.C.

Lithostratigraphic and biostratigraphic analyses were carried out on ditch cuttings samples from Amansiodo-1 well, Anambra Basin Nigeria. The lithostratigraphic description revealed the lithologies to be mainly shales, sandstones, clays, mudstones coal and siltstone. Biostratigraphic analysis shows a total of thirty benthonic foraminifera species recovered (twenty-six arenaceous and four calcareous) as a result three benthonic foraminiferal zones Ammobaculites amabensis/Miliammina pindigensis concurrent range zone, Haplophragmoides saheliense interval zone and Haplophragmoides talokaense interval zone was proposed for the well. The study also revealed shallow marine depositional environment based on the triangular plot of foraminifera suborders, paleobathymetric and paleo-oxygenation studies suggested the studied portion of the well belong to the Mamu Formation in the Anambra Basin. The well sediments are dated Maastrichtian based on the presence of Haplophragmoides saheliense an index fossil for Campanian Maastrichtian.