ABSTRACT: Clay mineralogy of the Upper Paleocene-Lower Eocene outcrops of the Dababiya Quarries has been studied by Dupuis et al. (2003). The Dababiya Quarry Corehole offers the opportunity to extend the mineralogical description to the middle and lower Paleocene as well as the upper Maastrichtian. Clay minerals are major detrital components of sedimentary rocks. They are generally produced in surficial continental processes such as weathering, paleosol development, lacustrine and lagoonal deposition, and erosion along hydrographic networks. They also interact strongly with littoral and marine environments which they may bypass or where they may accumulate. Here they are tentatively interpreted as markers of erosional history of adjacent continental areas and as an indication of sedimentary rate.