Petrogenesis and tectonic setting of gabbroic rock at Shakha Rash Mountain within Zagros belt, northeastern Iraq

Mafic rocks are dominant rocks in Shakha Rash Mountain, Shakha Rash occurs in the middle of Bulfat complex, which represents a part of in Zagros suture zone (ZSZ), northeastern Iraq. Gabbro, olivine gabbro, pyroxene hornblende gabbro and alkali gabbro are the main rock types of mafic rocks cropping out in the area. These rocks even its different variety rock types, its showing different granularity from fine to coarse texture. These mafic rocks are calc-alkaline affinity high aluminum basalt. Compared with the primordial mantle, they are enriched in Large Ion Lithophile Elements (LILE) and Light Rare Earth Elements (LREE) over High Field Strength Elements (HFSE) and Heavy Rare Earth Elements (HREE) close to oceanic arc basalt (OAB). Their enrichment in the LREE relative to HREE is relatively low fractionation (La_N/Yb_N) (1.64-3.31, ave. ~2.39) chondrite), with Eu anomalies changed from weakness negative to positive. This feature together with relative depletion of Nb, Pr, Nd, Zr, Hf and Ti but Cs, Ba, K, U and LREE enrichment. From trace element indicate that these rocks associated with volcanic arc basalt (VAB), this volcanic arc formed as a result of enclosed of Neo-Tethys. Trace and rare earth elements show that these rocks crystallized from magma melted from spinel lherzolite, by patch partial melting.