Petrography and Petrology of early Paleozoic bimodal metavolcanic rocks in North of Maku, North West of Iran

there are Discontinuous outcrops of volcanic rocks in the northern regions of Maku. The volcanic rocks were metamorphosed in the green schist facies. These volcanic complex were bimodal and compose of acidic and basic lava and pyroclastic rocks. The lava of this unit covers the Cambrian and equivalent of Lashkarak rock units and is progressively covered by Devonian dolomitic units. The geochemical data of metabasic and metarhyolite rocks signify transitional to alkaline nature of the primary magma and they have a negative gradient of REE and LREE / HREE ratio of those rocks are high and enriched inHFS elements. Metarhyolite rocks are similar to the rift setting rhyolites (A1-Type). Geochemical data indicate that the studied rocks are due to fractional crystallization of basic magma with crustal contamination, and in particular, the studied rocks have a genetic relationship and originate from a commen magma. The magma of the studied rocks generated by 3-10 percent partial melting of an enriched garnet peridotitic mantle source in an intra-continental extensional rift setting. This tectonic setting is concordant with the known extensional rift setting governed on other parts of Iran during the early Paleozoic, primary stages of generation and development of the Paleotethys.