Deep Water Planktic Foraminifera Biostratigraphy of the Western Niger Delta, Nigeria

Abstract

A high resolution and quantitative planktic foraminiferal biostratigraphic analysis was carried out on ditch cutting samples from KK-1 well from the offshore Niger Delta. The study was undertaken within the depth intervals of 15280 to 17670 feet with aim of subdividing the sequence penetrated by the well into planktic foraminifera biozones and also determine the biochronology. The standard technique for foraminiferal recovery was followed. Ninety planktic foraminifera species were identified in the well. The recovered planktics were rich and moderately preserved. Using the age diagnostic species and assemblages, the planktic foraminifera zones established in the study are the interval range zones of Catapsydrax dissimilis - Globigerina baroemoenesis Zone (N9-N15), Globigerina ciperoensis ciperoensis – Globigernoides primodus Zone (N4-N8), Globigerina ouchitaensis ouchitaensis – Globorotalia opima opima Zone (P20-P22), Hastigerina bolivariana – Globigerina ampliapertura Zone (P18-P20) and a lineage zone of Turborotalia cerroazulensis pomeroli - Turborotalia cerroazulensis Zone (P12-P17) respectively. The age of the studied interval ranged from middle – late Eocene to middle Miocene. The Eocene – Oligocene and Oligocene – Miocene boundaries were also established at the depth of 17410 ft and15720 ft respectively. Three biozones out of the five biozones established in this study correlate well with parts of the Niger delta, the Mediterranean and some other low latitude areas.