Thermophysical properties of rocks from the Bushveld Complex

This paper presents a compilation of physical properties of rocks from the Bushveld Complex. The database consists of more than 900 measurements each of thermal conductivity and density. The data are well distributed from localities around the Complex and most rock types are well represented. Thermal conductivity and density are shown to vary widely in the ranges 1.8-4.2 W m(-1) K-1 and 2600-4200 kg m(-3) respectively. Although only 190 heat capacity measurements are available, this parameter is quite uniform for most rock types present, 800-900 J kg(-1) K-1, except for chromitite, which has a lower average, 750 J kg(-1) K-1. Rocks encountered in deep platinum mines are particularly well characterized and this has important implications for prediction of mine refrigeration requirements. The heat flux into a semi-infinite region with properties typical of the Bushveld Complex as a function of time is substantially lower than an equivalent model for the Witwatersrand Basin.