Petrology and geochemistry of Kuh-Siyah and Tahmoures areas young volcanic rocks, Kurdistan

At the structural of Sanandaj - Sirjan, Zone of Iran (Kurdistan providence) Kuh-Siyah and Tahmoures young volcanic rocks are exposed. The main phenocrystals of these rocks consist of olivine and clinopyroxene. These metaluminous rocks are combinations of trachy basalt, basalt to havaiite have shoshonitic to alkaline affinities. Based on geochemical studies, the partial melting of a garnet - spinel Lherzolitic source was responsible for the magma generation. The basic rocks, have LILE enrichment and low content of HFSE. Enrichment of LREE can influence magmatic evolution (High depth and low partial melting degree) and tectonic setting of the formation of rocks, attributed. Significant depletion of HREE could be as a result of residue of the mineral garnet phase in the liquid production process. The studied alkali-basalts have all the high Nb basalts signatures such as Nb>18 ppm, Sr/Y>25, La/Yb>14, low Rb/Sr and Yb. Hence these are high Nb basalts, but isotopic investigations are required to confirm it.