ENRICHMENT OF PLATINUM AND ASSOCIATED ELEMENTS IN ORGANIC SEEPAGE SOILS OF THE TULAMEEN ULTRAMAFIC COMPLEX, SOUTHERN BRITISH-COLUMBIA

Concentrations of Pt have been determined in seepage waters, organic s oil horizons and trees in and upslope from a seepage site on the dunit e core of the platiniferous Tulameen ultramafic complex. The concentra tions of Pt (together with Sb, Cr, Ni, Pr, Co, As and Cu) are enhanced twenty-fold in the organic seepage soils compared to Pt concentration in both the LFH horizons of the upslope soils and Pt concentrations f ound in the ash of twigs and bark of trees growing on the seep. The se epage waters contain 0.4 to 0.8 ng/L Pt. The study provides evidence t hat weathering under temperate conditions can release Pt from platinum group minerals and that the released Pt can then be transported, eith er in solution or a colloidal form, to seepage sites where it is accum ulated by organic matter. Organic-rich soils from seepage sites might therefore provide suitable sampling media for geochemical surveys for Pt.