Trace element distribution in chromitites from the pindos ophiolite complex, greece: implications for chromite exploration

摘要

Compilation of new and published data on bulk rock analysis for PGE, Ni, Cu, Co, V, Zn and Ti in chromitites from the Pindos ophiolite complex indicate a PGE-enrichment (up to 7 ppm) mostly in Pt and/or Pd, altherough the PGE content is generally low (a few hundred ppb). The Ti, V, Zn, Co and Cu content is higher in high-Al chromite ores than in high-Cr ores. These ores are considered to have formed from separated parent magmas of tholeiitic and boninitic composition, respectively, probably related to a fore-arc geo-tectonic environment, along a transform fault. A fractionation trend in PGE-enriched chromitite occurrences hosted in supra-Moho dunites and dunites from the uppermost stratigraphic levels of the mantle sequence, may be denoted either by an increase in iron, PGE, Cu, V, Ti and Zn content, or by these trace element content only. The well pronounced fractionation trend in the Pindos chromitites may reflect the absence of uniform conditions over large areas (large volumes of magma) and we suggest that these ophiolites are not good exploration targets for chromite.