An emplacement model for Esfandagheh and Faryab ultramafic-mafic complexes, Kerman province, south east Iran

摘要

The Paleozoic ultramafic-mafic Esfandagheh and Faryab complexes with an annual pro-duction of 50,000 MT chromitite ore are located in the Kerman province, south east Iran. They are composed of rhythmic layers of dunite, chromite, harzburgite and some pyroxenite, wherlite and gabbro. Most of the chromite deposits (70%) occur as discontinuous layers, the rest of it is found as lenticular chromite ore. There is a positive correlation between the Cr and IPGE concentrations in these areas. On the other hand, at Esfandagheh and Faryab, a concentration of IPGE of more than one hundred ppb indicates that this increase of (Ir) concentration could be the sign of boninitic magma and Alpine type IPGE deposits in the chromitite zone in these areas. The geochemical characteristics of the ultramafic and mafic rocks and of the chromite ore in these areas suggest that chromite de-posits and ultramafic host rocks are of the Alpine type and derived from boninitic magma and some depleted pridotite probably in the supra subduction zone. The complex had a post-Cretaceous vertical mechanical emplacement.