Synchrotron X-ray radiation and the African earth sciences: A critical review

Abstract Synchrotron-based X-ray analytical techniques are gaining in prominence as a crucial yet highly specialized tool for advancing knowledge within the broad field of the Earth Sciences. In terms of global scientific competitiveness, African scientists are somewhat disadvantaged by not having access to their own synchrotron on the African continent. However, there currently exists a strong drive towards obtaining a synchrotron X-ray facility on the African continent and the purpose of this critical and timeous review is thus to highlight the importance of such equipment for the local earth science community (e.g., geologists, geochemists and palaeontologists). Our review shows that various high-level synchrotron X-ray spectroscopies have been successfully applied to African earth samples and that the outputs of these studies have measurable societal benefit in terms of improved understanding of fundamental earth processes (including the molecular level controls on earth climate cycles), improved characterization of important and economic ore commodities (including drill core samples), and improved understanding of the fate and mobility of deleterious elements in the surface environment (e.g. soils and waterways). Similarly, the high phase contrast and rapid acquisition capabilities of synchrotron X-ray computed tomography (sXCT) have added important insights into a wealth of samples derived from Africa's fossil inventory (>350 specimens). Not only these studies advance our understanding of all ancient life forms, shedding light on our origins, they contributed to the training of the next generation of palaeontologists and the dissemination of science in Africa. It is foreseen that this review will stimulate further use of synchrotron technologies by the local earth science community whilst concomitantly developing a strong scientific case for considering and incorporating the needs of the earth sciences when the time comes to develop an African synchrotron facility (i.e., the African Lightsource).