Evolution of the dissolved oxygen content of water during the Coniacien-Santonian interval from the KM well of Côte d ’ Ivoire ) Par :

The study of foraminifera collected from 38 samples Spoil wells KM (Sedimentary basin of Côte d’Ivoire) has established paleoenvironmental had ruled deposition of sediments from the interval 2074 m and 1687 m. It was identified 258 individuals including 32 planktonic foraminifera (12,4%), 92 agglutinated benthic foraminifera (35,66%) and 134 calcareous benthic foraminifera (51,94%). Based on the first or last appearances of planktonic forms, the Coniacian-Santonian interval (lower Senonian) was determined. This period is marked by stratification. Indeed, the base of this interval is marked by a shallow marine environment and very little oxygen. However, at the top, stands a strong field with an increase in dissolved oxygen content that promotes proliferation microfaunas both in seabed and in the water column.