A compilation of new and recent magnetostratigraphic interpretations anchored by geochronologic data for the Permian to Triassic sediments of the Karoo Basin, southern Africa.

Magnetostratigraphic investigations of the Karoo Basin have multiplied in number over the past few years, with several studies focused on the Permian period. Sedimentary deposits from this time are particularly thick, reflecting the onset of Cape Fold Belt deformation and uplift. The magnificent rock exposures reveal an abundant vertebrate fossil record, which has been studied extensively since the early 20th century. A prominent faunal turnover is identified by the transition between the late Permian Dicynodont and early Triassic Lystrosaurus genera. This boundary is commonly interpreted as the continental equivalent of the Permian-Triassic boundary, the horizon that marks the largest mass extinction in Earth history. In this contribution, we will present an overview of new and recent magnetostratigraphic results as well as presenting new geochronological (U-Pb SHRIMP and ID-TIMS), thermochronological (40Ar-39Ar, detrital muscovite; U-Th-He, zircon and apatite) These results are compiled for inclusion into the Global Polarity Timescale for a ~30 Myr period starting at ca. 280 Ma (middle Ecca Group), through 265—260 Ma (basal to middle Beaufort Group), and terminating at the ca. 252 Ma Permian-Triass boundary (uppermost Beaufort Group). This contribution will explore some of the hurdles to be overcome for recovering accurate paleomagnetic and geochronologic results: burial metamorphism associated with the Cape Fold Belt deformation, the lateral heterogeneity of fluvial sedimentary facies, and the thermal overprint caused by the Jurassic intrusion of the Karoo Large Igneous Province.