[en] The behavior and chemical characteristics of fluids during normal sedimentary basin evolution are reviewed, and the 'anomalous' mineralogy of the Witwatersrand is examined in this light. An assessment of the likely diagenetic processes in the Witwatersrand Basin can be made by reviewing the types of diagenetic processes occurring in modern sedimentary basins comprised dominantly of sandstones and shales, and looking for critical features of such processes in the ancient Witwatersrand strata. During burial and thermal diagenesis of sediments, major changes occur with respect to mineralogy and the transfer of chemical constituents between the coarse- and fine-grained units in the basin. Some of the diagenetic processes from younger basins are briefly reviewed. These processes are used as a basis to discuss the likely diagenetic history of the Witwatersrand Basin. Gold and uranium mineralization in the Witwatersrand Basin is also discussed. 68 refs., 7 figs., 2 tabs