Abundance and distribution of CuFeNi sulfides, sulfur, copper and platinum-group elements in orogenic-type spinel lherzolite massifs of Ariege (Northeastern Pyrenees, France)

摘要: Modal sulfide variations, together with sulfur, copper and platinum-group element (PGE) geochemistry have been investigated in 58 spinel peridotite samples from orogenic-type massifs of Ariège (northeastern Pyrenees, France). These rocks are considered to record a sub-continental evolution marked by low to moderate degrees of partial melting in the garnet stability field. The peridotites contain spinel and/or garnet pyroxenitic layers and are locally cross-cut by amphibole-pyroxenite and hornblendite dykes. The peridotites sampled at distances > 50 cm from pyroxenites contain high-Ni, low-Cu sulfides which are considered to have survived mantle partial melting. The less depleted lherzolites have S, Cu, Pb and Pt contents closely similar to those of the Ivrea Verbano mantle peridotites, but in excess of upper mantle estimates based on spinel lherzolite xenoliths from alkali basalts. These rocks display nearly …