Lithostratigraphy of the Clarens Formation (Stormberg Group, Karoo Supergroup), South Africa

The Lower Jurassic Clarens Formation is a sandstone-dominated unit that extends from its type area in the main Karoo Basin into a large part of southern Africa with a gross lithological uniformity that is one of its key diagnostic features. The impressive cream sandstone cliffs of the unit are often undercut and form shallow caves. Stratigraphically, the unit is sandwiched between the underlying red beds of the Elliot Formation and overlying flood basalts of the Pliensbachian-Toarcian Drakensberg/Lebombo Groups. The fine to very fine-grained, massive to large-scale cross-bedded sandstone beds formed in a laterally extensive erg system that stretched across most of southern Gondwana from the Sinemurian to Pliensbachian. Regional variations in its sedimentary facies, thickness and fossil content exists, and are likely linked to climatic changes and to the early manifestations of Gondwana break-up. Insights gained from the Clarens Formation, via an imminent high-resolution study that integrates results from modern facies analysis, geochronology and biostratigraphy, can provide an improved understanding of the global climate in the Early Jurassic.