TITLE:
Miocene Foraminifera Biostratigraphy and Interpretation North Deep Sea Block of the Congolese Atlantic Basin
AUTHORS:
Nehl Dorland Kobawila, Hilaire Elenga, Louis Richard Ngatse
KEYWORDS:
Biostratigraphy, Foraminifera, Palaeoenvironments, Miocene, Congolese Atlantic Basin
JOURNAL NAME:
Open Journal of Geology,
Vol.11 No.7,
July
26,
2021
ABSTRACT: This work is the subject
of the biostratigraphic and palaeoenvironmental study of the North Deep Sea
area of the Congolese Miocene Atlantic Basin. This study is made from samples
of lateral cores, drill cuttings and electrical logs. Lithology generally
exhibits an irregular alternation of weakly indurated grey clay, light grey siltstones, and whitish,
quartzitic sand, medium to coarse-grained, sub-angular to rounded. The
presence of glaucony indicates that sediments have been deposited in a calm and
reducing environment. The entire formation is fossiliferous. Micropaleontological
analysis revealed 120 species of foraminifera including 98 planktonic (81.67%)
and 22 benthic (18.33%) species used for biozonation, dating and interpretation
of palaeoenvironments. Similarly, the bio-events of plankton foraminiferal,
characterized by the level of the first
appearance of certain species, have made it possible to identify fifteen
biozones (Globorotalia plesiotumida, Globorotalia merotumida, Globorotalia acostaensis, Globorotalia menardii, Globigerina nepenthes, Globorotalia siakensis, Globorotalia fohsi, Globorotalia praefohsi, Globorotalia peripheroacuta, Globorotalia peripheroronda, Praeorbulina sicana, Catapsydrax dissimilis, Globigerinatella insueta, Paragloborotalia
kugleri and Globorotalia kugleri)
corresponding to age between Aquitanian and Lower Pliocene. Biofacies analysis
of foraminifera has identified palaeoenvironments that vary from open marine
environments, bathyal to abyssal.