Tectonic setting and Petrogenesis of the mafic and dioritic dykes, S-Qorveh (Kurdistan)

The study area is located in the south of Qorveh (Kurdistan Province), strcuctually in the Sanandaj-Sirjan zone. Based on field observations, the study dykes are type of sin-plotonic dykes and based on petrographical studies mafic and dioritic dykes are included gabbro, gabbro-diorite, diorite, monzodiorite and quartz-monzodiorite rocks. Their main minerals are clinopyroxene, orthopyroxene, hornblende, plagioclase, K-feldspar and quartz. Apatite, esphene, zircon and opaque minerals are their accessory minerals. The discrimination diagrams reveal all of the dykes belong to volcanic arc related to an active continental margin setting. It is implied by enrichment of LILE (such as Cs, Rb, U&Pb), depletion of HFSE (Nb, Ba) and high LILE/HFSE in the spider diagrams. The enrichment of LILE and Pb show the crustal contamination. Concentration La/Nb and La/Ta rations as well as the enrichment of LREE and LILE reveal that dykes were derived from enriched lithospheric mantle. I addition, enrichment of LREE elements relative to HREE represent that there are garnet phase or amphibole in source.