TITLE:
Late Cretaceous/Early Paleocene Biostratigraphy of the Northern Portion of the Bornu Basin, Nigeria
AUTHORS:
Peter S. Ola, John A. Adekoya, Solomon O. Olabode
KEYWORDS:
Microflora, Microfauna, Cretaceous, Unconformity, Formation
JOURNAL NAME:
Open Journal of Geology,
Vol.6 No.7,
July
15,
2016
ABSTRACT: 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.