A hornblende diorite plug with gabbroic and possible lamprophyric affinities has been located on the farm Eausiro West 101 in the Erongo Region, central Namibia (Fig. 1). The intrusion is at least 400 metres in diameter, but, due to the poor exposure, the distribution of the dioritic, gabbroic and lamprophyric phases cannot be accurately determined. The discovery was made during reconnaissance mapping conducted as part of a mineral exploration program (Steven, 1987). Attention was focused on the area after the identification of considerable quantities of magnetite in the thin residual soil. A prominent aeromagnetic anomaly that covers much of the farm is probably related to this intrusion (see aeromagnetic map 2115BA, scale 1:50,000).