Fields of study

The origin of an unusual Jurassic-Cretaceous has not entirely been determined. The deposits in the Kirkwood Formation of the Uitenhage Group are as a result of the breakup of Southwestern Gondwana. Reshaping the breakup of Southwestern Gondwana has proven to be complex as majority of the basins have been buried deep underneath passive marine margins. In addition, there are no marine constituents, only continental tectonic activity, which means there are no marine microfossils indicating age or chronological sequence (McMillan et al., 1997). The deposition of the sediments of the Kirkwood Formation occurred during the Jurassic-Cretaceous period (~180- 135 Ma). It is situated in the distal parts of the Uitenhage Group where the energy conditions are generally low, it is characterised by fine-grained sedimentary rocks such as sand and mud. The sediments of this Formation are interbedded with volcaniclastic ash from a distal volcanic source. The deposit with an unusual thickness was observed, it does not follow the trend of the Kirkwood Formation. Furthermore, the deposition of the rock is synchronous with the Morokweng meteorite impact that occurred ~700km away However, the well exposed erosional remnants of the Uitenhage group in the southern cape of South Africa gave more opportunity for further assessment of the conditions surrounding the rifting in this region. Furthermore, this region consisted of volcaniclastic deposits that have been recognized (Muir et al., 2017a, Muir et al., 2017b). An unusual ash deposit is exposed in a quarry in the southern Cape of South Africa. The purpose of this project is to investigate the origin of this deposit. The origin could either be volcanic or impact-related origin of the unusual rock and, if shown to be volcaniclastic, helps reconcile the lack of any known nearby volcanic source with its texture and thickness. The methods to be employed here are: Petrographic thin-section analysis, Scanning Electron Microscopy (SEM), X-Ray Diffraction (XRD) and X-Ray Fluorescence (XRF).