Adaeze I. Ulasi
The sedimentary process of Umunya isa replica of what took place in the ancient time and gave rise to prolific reservoirs of the Niger Delta Fields like the Agbami and BongaGiant Fields. Little work has been done in this section to ascertain its geology. The need for such knowledge is pressing. As a step towards understanding this geohistory, this study examines the stratigraphy and sedimentary structures of the Umunya section of the Eocene Nanka Formation, a component of the Ameki Group of the Niger Delta Basin. From a panoramicview across the Onitsha/Enugu express way, the lenticular Umunya section is observed to comprise three subunits. This interpretation is supported by abundant sedimentary structures indicative of tidal influence (clay drapes, reactivation surfaces, cross-bedding, and heterolith). The exposure is considered as one of the most instructing and educating field trip destinations in the area. The field demonstration of Walther’s Law, clastic sedimentary structures, reservoir properties, SequenceStratigraphy, variability in depositional environments and techniques in environmental diagnosis is evident.