Ditch cutting samples from Kasade-1 well were processed for microfauna, nannofossil and palynomorphs to throw more light on biostratigraphic events in the northern portion of the Bornu Basin, Nigeria. The lower sectio...Ditch cutting samples from Kasade-1 well were processed for microfauna, nannofossil and palynomorphs to throw more light on biostratigraphic events in the northern portion of the Bornu Basin, Nigeria. The lower section of the well within interval 990 - 1565 m yielded fairly abundant foraminifera species, while the upper section was barren. Palynomorph distribution follows the same pattern as observed for foraminifera except that few fresh-water algal species, Botryococcus braunii, were recovered from the upper section. The samples are devoid of nannofossil but contain few ostracod species, echinoid remains and fish tooth. Recognition of two planktonic foraminifera zones, Globotruncanella havanensis and Globotruncana aegyptiaca, enabled the delineation of the Campano-Maastrichtian and Maastrichtian boundary. The Cretaceous Tertiary boundary was inferred based on the top occurrence of palynomorph Dinogymnium euclaense. An abrupt truncation in the distribution of foraminifera species at a depth of about 990 m suggests unconformity, a widely reported event that followed the Santonian squeeze in the entire mega-Chad Basin.展开更多
Palynological study of an offshore well in the Niger delta was carried out to document the palynomorphs assemblage and subsequently date and establish paleoclimatic conditions in a portion of the Niger delta. One hund...Palynological study of an offshore well in the Niger delta was carried out to document the palynomorphs assemblage and subsequently date and establish paleoclimatic conditions in a portion of the Niger delta. One hundred and thirty seven cutting samples provided by Chevron Nigeria Plc were composited at 27 m interval for the study. The samples yielded forty six palynomorphs, which include Racemonocolpites hians, Zonocostites ramonae, Monoporites annulatus, Botryococcusbraunii, dinocyst Lycopodiumsporites spp., Pachydermitesdiederixi and Psilatricolporitescrassus. A Middle-Late Miocene age belonging to P800 and P700 zones of Germeraad was established for the interval studied. There were clear crests and troughs in the microfloral abundance indicative of alternations of dry and wet climatic conditions during the deposition of the Agbada Formation.展开更多
文摘Ditch cutting samples from Kasade-1 well were processed for microfauna, nannofossil and palynomorphs to throw more light on biostratigraphic events in the northern portion of the Bornu Basin, Nigeria. The lower section of the well within interval 990 - 1565 m yielded fairly abundant foraminifera species, while the upper section was barren. Palynomorph distribution follows the same pattern as observed for foraminifera except that few fresh-water algal species, Botryococcus braunii, were recovered from the upper section. The samples are devoid of nannofossil but contain few ostracod species, echinoid remains and fish tooth. Recognition of two planktonic foraminifera zones, Globotruncanella havanensis and Globotruncana aegyptiaca, enabled the delineation of the Campano-Maastrichtian and Maastrichtian boundary. The Cretaceous Tertiary boundary was inferred based on the top occurrence of palynomorph Dinogymnium euclaense. An abrupt truncation in the distribution of foraminifera species at a depth of about 990 m suggests unconformity, a widely reported event that followed the Santonian squeeze in the entire mega-Chad Basin.
文摘Palynological study of an offshore well in the Niger delta was carried out to document the palynomorphs assemblage and subsequently date and establish paleoclimatic conditions in a portion of the Niger delta. One hundred and thirty seven cutting samples provided by Chevron Nigeria Plc were composited at 27 m interval for the study. The samples yielded forty six palynomorphs, which include Racemonocolpites hians, Zonocostites ramonae, Monoporites annulatus, Botryococcusbraunii, dinocyst Lycopodiumsporites spp., Pachydermitesdiederixi and Psilatricolporitescrassus. A Middle-Late Miocene age belonging to P800 and P700 zones of Germeraad was established for the interval studied. There were clear crests and troughs in the microfloral abundance indicative of alternations of dry and wet climatic conditions during the deposition of the Agbada Formation.
