Petrology of rocks in the Karik area, east of Meiduk mine of volcanic

Around The Karik village, east of Meiduk mine, Eocene volcanic rocks (andesitic basalt, andesite, dacite and rhyolite) and pyroclastic rocks (agglomerate and tuff) are exposed. These rocks are cut by several andesitic dikes. The major textures in the volcanic rocks are porphyritic and flow textures. The minerals such as plagioclase, alkali feldspar, quartz, pyroxene, amphibole, biotite and opaque are present as phenocrysts and fine grains. Sometimes, feldspar crystals (mainly plagioclase) are found as oriented microlites. In some cases, within the plagioclase phynocrysts disequilibrium textures such as sieve texture, corrosion and zoning are observed. Quartz crystals are corroded. Amphibole and biotite crystals are changed into Fe-Ti oxides on their rims. These textures are probably attributed to magma mixing, water vapor changes and decompression due to rapid ascent of magma. The Karik volcanic rocks are calc-alkaline and mainly metaluminous in nature. Primary mantle and chondrite normalized multielement diagrams for the study rocks are spiked and they have several peaks and troughs. In the diagrams, the depletion of the high field strength elements such as Nb, Ta, Ti and P is obvious which is characteristic of the subduction magmatism. The sharp positive anomaly of Pb might be attributed to crustal contamination. The chondrite normalized RRE pattern of the study rocks is relatively smooth with enrichment of LREEs relative to HREEs that is due to the high abundance of LREEs in the source or crustal contamination. According to the petrological and geochemical evidence, the Karik volcanic rocks are formed in an active continental margin setting due to the subduction of Neothetys oceanic lithosphere beneath the Central Iran micro–continent.