Facies analysis, cyclic sedimentation and paleoenvironment of the Middle Eocene Rus Formation in Qatar and adjoining areas

The Middle Eocene Rus Formation in Qatar and adjacent area consists of evaporite-carbonate sequences. The Rus Formation extends over a large area in the Middle East and can be correlated with confidence throughout the eastern Arabian Peninsula. In this study, the Rus Formation in Qatar is redescribed and subdivided into two new members from bottom to top: the gypsiferous dolomitic limestone Traina Member and the chalky limestone Al-Khor Member. These units were deposited in two different depositional settings ranging from supratidal to subtidal environments. Seven lithofacies are recognized from studied surface and subsurface sections throughout the Rus Formation. These are limestone, chalky limestone, dolomitic limestone, cherty limestone, marl, claystone and gypsum. These facies show a cyclic sedimentation in southern Qatar.