Abstract

The Jessu Formation is one of the marine Cretaceous sediments in the Yola Sub-basin of the Northern Benue Trough, NE Nigeria. Lithofacies studies was carried out on the Jessu Formation exposed at Dukul and Cham streams outcrops, in order to identify facies, establish facies association and re-construct the paleodepositional environment. Ten (10) facies were identified on the bases of lithology, grain size, sedimentary structures and degree of bioturbation. These facies form four (4) facies associations, namely: the FA-1 (offshore marine), FA-2 (lower shoreface), FA-3 (middle shoreface) and FA-4 (upper shoreface). These facies associations form coarsening upward units from offshore marine to shoreface which suggests a shoreface deposit for the Jessu Formation. The coarsening upward facies succession indicated storm and wave influenced coastal system.

Key words: Lithofacies, Coastal System, Cretaceous, Jessu Formation, Yola Sub-basin