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Tin.' Plalrecf is a pl.ttinum group (•Ifnii'tiis atitl ha.sc mcVdl ctiiiehc<.l inariLV itlttitiiuilK lave-r situated along [lie ha.se ol il limb uf the Bu.shvL'ld Ccmiplt^x. The present siutly fotiiaiti.i ;t LlL-Liiled petrographic an<.l geotlitniical inve.stigatioii of a Ixircliole fore intersection tliroiij;h tlic Platreef on the farm lowtilands. At this loLitlity, the I'latreef re.si.s on tnet>i,sediTiientaty rocks of the .Silveiion l-'oniuttion of ihe Transvaal SupiTgnatp, atnl is toinjirLsL-d of (Inw tnediuni-grained units of gabhronoriti.Vfeldspathic pyroxenile ihat are .sepanued hy hornfels interlayers. We refer lo (iie (hn-e plaiiniferous layers a.s the Lower. Middle atid I'pper Flatreef. The Middle Philreef is the tnain ininerali.setl layer, with total FGH contents ttp to 4 ppm. The Lower and L'pper Plaireels are less well iiiitiftitlised (tip to I.T ]ipm).Trace eletnetit antI .s-isotopi.-data sliow compositional breaks ht'tw-een the different platiniferous layers .suggesting that tliey represent tlistinct silMike intru.sions of pyroxene atid sulphide enriched cr>'stal tnu.shes. The study also reveals a reversed diffetentiation tivnd of more pritnitive rocks towards the top of ihe succession. For exatnple. orthopyroxene .shows an increase in C;r/_), from 0.07 to 0.37 weight "AI wiih height and the whole rotk concentration of incotnpatibk' trace elements .such as ^' and Zr decrea.ses. This pattern is inierpreted to rellect enhanced cntstal conianiinatioti ot the lower Platreef layers.

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