The Karoo Supergroup: Modern insights from the ancient archive of Gondwana

Abstract The Karoo Supergroup of southern Africa offers a valuable record of Gondwana’s late Palaeozoic to early Mesozoic evolution over ~120 million years of geological history. This review synthesizes advances in sedimentology, stratigraphy, palaeontology, and basin analysis in the main Karoo Basin since 2000, highlighting key lessons and ongoing challenges. Significant developments include: (1) a refined flexural foreland basin model and the recognition of extensional overprinting in the Early Jurassic; (2) palaeoclimate reconstructions revealing non-linear shifts, particularly in the upper Karoo, challenging previous ideas on gradual aridification; (3) revised biozonation and expanding fossil records demonstrating ecosystem resilience during mass extinctions (end-Permian, end-Triassic); and (4) an improved chronostratigraphic framework through volcanic ash and detrital zircon geochronology and magnetostratigraphy, facilitating pan-Gondwanan correlations. However, critical unresolved questions remain regarding the precise nature and timing of formation boundaries; the relative roles of tectonics versus climate in facies changes; within-basin heterogeneity, sediment source links, and detailed correlation with global events. Future progress requires high-resolution stratigraphy integrating new geochronological data through denser sampling across critical boundaries; AI-assisted facies analysis and remote sensing applications to address correlation challenges and basin heterogeneity; expanded palaeontological and ichnological surveys; and synthesis of tectonic models with lessons from the sedimentary record. Coupled basin evolution models linking sedimentology, geochemistry, and geochronology are essential to resolve drivers of stratigraphic architecture. Assessments of resource potential (groundwater, CO2 storage, mineralisation) must consider the impacts of dolerite intrusion on basin-fill compartmentalisation. Revitalised institutional oversight by the South African Committee for Stratigraphy (SACS) is needed to formalise units and standardise frameworks. The Karoo’s significance extends beyond Gondwana, offering insights into responses to supercontinental dynamics and fragmentation, climatic extremes, and biological crises. The Karoo remains a global deep-time laboratory for understanding tectonic-climatic-biotic interactions, but ongoing stratigraphic refinement is essential for unlocking additional Earth system insights and resource potential in southern Africa.