Petrography, whole rock chemistry and study of formation condition of amphibolites in east of Salmas, northwest of Iran

The amphibolites of east Salmas, as one of the widest units of the metamorphic complex, are located in the northwest of Sanandaj-Sirjan zone, which according to field studies are mainly oriented and foliated amphibolites. Based on microscopic studies, amphibolites include amphibolites, biotite-amphibolites, epidote-amphibolite, biotite-epidote-amphibolite, tremolite-actinolite-amphibolite, and biotite-clinopyroxene-amphibolite. Amphibolite specimens of the region have maximum parallel pattern based on the variation diagrams of rare earth elements normalized to chondrite, EMORB and primary mantle and are similar to intra-plate basalts in terms of geochemical properties. According to the results of whole rock chemistry, the study amphibolites are mainly ortho-amphibolites with a basaltic protolith and calc-alkaline magmatic series, which are located in the intra-plate tectonic position.