Schematic log of the Clarens-1 (CLS-1) borehole with the vitrinite reflectance data used in this study. Note the 500 m large zone which presents the fault zone and the different levels of sedimentary breccia (B1 to B4) observed on the drill core. VR, AFT, ZHe and IF refer to the position of the Vitrinite Reflectance data, Apatite Fission Track sample, (U-Th)/He on zircons samples and fluid inclusions samples, respectively.