geochemistry and tectonic setting of maien bolagh (takab) alkali gabbros-nw iran

some small gabbro patches emplaced along the thrust fault with w-e trend in the vicinity of maien bolagh village at the ht/mp metapelites, a part of the central iran zone (near to sanandaj-sirjan zone). the coarse-grained dark gabbro samples consist of amphibole, clinopyroxene, plagioclase, minor quartz, titanite, and biotite. gabbros have high potassic calc-alkaline to shoshonitic affinity. the highly incompatible elements concentrations (e.g. nb and la) and zr/y and zr/nb ratios are similar to within plate gabbros. at the assorted discrimination diagrams the gabbros exhibit mostly non-orogenic resemblance. the geochemical characteristics show that the gabrros can be interpreted as melts formed from an enriched mantle in a passive rift position, during an extensional or transtensional tectonic