अनुप्रयुक्त विज्ञान अनुसंधान में प्रगति खुला एक्सेस

अमूर्त

Sequence Stratigraphy and Palynological Analysis of late Campanian to Maastrichtian Sediments in the Upper-Cretaceous, Anambra Basin. A Case Study of Okigwe and its Environs, South-Eastern, Nigeria

Chiaghanam O.I., Ikegwuonu, O.N., Chiadikobi K.C., Nwozor K.K., Ofoma A.E. and Omoboriowo, A.O

Sediments recovered from Leru, Uturu and Ihube area in Anambra Basin, South-eastern Nigeria was analysed for their palynological and sequence stratigraphic potentials. Using palynological evidence, Late Campanian age was assigned to Nkporo Shale (Leru), and Early-Middle Maastrichtian to Mamu Formation (Uturu) on the basis of some age diagnostic taxa e.g Longapertites marginatus, Cingulatisporites ornatus, Buttinia andreevi and Retidiporites magdalenensis, Rugulatisporites caperatus and Gleicheniidites senonicus. The lower unit of Nsukka Formation at Ihube was dated late Maastrichtian age based on stratigraphic age makers such as Dinogymnium sp. and Spinizonocolpites baculatus. A marine to brackish water environment was suggested for Nkporo Shale and brackish to fresh water environment for Mamu Formation while near shore water environment was assigned to Nsukka Formation, based on the important environmentally significant species encountered. The logged outcrops show presence of key stratigraphic surfaces and also system tracts with highstand systems tracts dominating.