High Resolution Palynological Studies Of Upper Cretaceous Succession Of Mushe-1 Well Central Chad Basin Nigeria

Abstract These The Late Cretaceous succession penetrated by Mushe-1well in the Central Chad Basin North East Nigeria was investigated for its palynological content. This investigation produced biostratigraphically significant Pollen Spore and dinoflagellate cyst. The studied interval penetrated a sequence of clay sandstone shale shally sandstone sandy shale and sandstone occuriing at different intervals in all the wells. Based on the stratigraphic distribution of the palynomorphs from the Mbeji-1 well. Twelve informal assemblage palynozones and six dinoflagellate assemblage biozones spanning the Upper Cretaceous were identified in the Chad Basin Nigeria. The zones are Assemblage Zones I-IV Cenomanian Assemblage Zone V Turonian Assemblage Zone VIVIIVIII and IX Coniacian-Santonian and Assemblage Zones XXI XII and XIII Campanian-Maastrichtian for the PollenSpore biozones.. The age determinations are based on the known stratigraphic ranges of pollen spores and dinoflagellate and their relative stratigraphic positions. Data from the studied well revealed that generally in the basin there is relatively higher frequency of the land derived pollen and spores compared to marine palynomorph abundance which suggests a paralic condition of continental to shallow marine environment. The shallow marginal marine environment is further supported by the presence high diversity of dinoflagellate species and foram test linings at some depths which are indicative of marine paleoenvironment i.e. neritic environment.