Cyclostratigraphy of the formations of the Ivorian terminal continental: Case of the "RO" drilling of Aboisso, South-East of Côte d'Ivoire.

The RO drilling is located in the Ivorian Onshore Basin in the Aboisso area. To find a suitable area to meet the potable water needs of Abidjan city, litho-granulometric and log analyzes were carried out on forty-three (43) samples, to understand the sedimentary cyclicities in the establishment of hydraulic reservoirs (aquifers) along the borehole. The lithological results reveal six (6) lithologies which are among others sandy gravels, gravelly sands, kaolins, quartz sands, sandy-muddy gravel, and silty-clayey sand, which alternate all along drilling. These different alternations allowed the establishment of 42 lithological cycles, of which 35 were binary cycles, 6 ternary cycles, and a single quaternary cycle. The grain size results show that the sand fractions of these lithologies are coarse to very coarse, moderately graded to poorly graded, Platikurtic, with negative to positive asymmetries. Through these granulometric parameter arrangements, 23 cycles of grain size, 30 cycles of classification, 27 cycles of asymmetry, and 9 cycles of kurtosity were counted. The log signatures show 12 cylindrical shapes, 4 bell shapes, 3 jagged shapes, 3 egg shapes, and one funnel shape giving a total of 23 cycles. They indicate the existence of anastomosing and meandering fluvial systems. [ABSTRACT FROM AUTHOR]