FIG. 1. (a) Map showing the laurite sample locality (open star), towns and villages (open squares) and selected features relevant to the placer PGM occurrences in southeastern Kalimantan. They include diamond-Au-PGM placers (dotted areas), PGM-Au placers (solid colour), podiform chromitite deposits (solid circles), ultramafic rocks (hatched pattern), and the Manunggul Formation (inclined stripe). The detailed geology of the dotted rectangular area close to the laurite location is shown in Fig. 1b. The Late Cretaceous sedimentary and mafic volcanic rocks of the Manunggul Formation appear to be the source of the diamond-bearing placers. Modified from Zientek et al. (1992). (b) Geological map of the Riam Pinang area, South Kalimantan. The location of the laurite samples is shown relative to the native gold-platinum-iron alloy-bearing placers downstream from Riam Pinang (area with PGM observed in pan concentrate samples). Modified from Zientek et al. (1992).