Uncertainties on Basal Khuff Clastics in Outcrop in Saudi Arabia

Various types of clastic and mixed clastic-carbonate deposits represent the transition from the pre-Hercynian and Hercynian Palaeozoic formations and the marine Khuff carbonate in Saudi Arabia. Due to sedimentary and erosional hiatuses, the complexity of this sedimentation is particularly reinforced near the outcrop and on top of the Central Arabian Arch or of the Rayn Plate. Therefore, age and lithostratigraphic assignments of the litho-units resting underneath the Khuff carbonate are often uncertain or questionable. In order to avoid unconsidered assignments to a particular formation of these sediments prior to any critical analysis of the retained criteria, this study proposes a review of typical uncertainties and proposals of clarification.