Eocene Calc-Alkaline Volcanic Rocks from Central Iran (southeast of Khur, Isfahan Province); an Evidence of Neotethys Syn-Subduction Magmatism

Eocene volcanic rocks with basaltic-trachyandesite and trachybasalt composition which cross-cut the Cretaceous sedimentary rocks, are exposed in the northwestern part of the Central-East Iranian Microcontient (CEIM) (SE of Khur, Isfahan Province, Iran). The rock-forming minerals of these volcanic rocks are olivine (chrysolite and hyalosiderite, Mg# = 0.69–0.71), clinopyroxene (augite with Mg# = 0.74–0.84), orthopyroxene (enstatite with Mg# = 0.61–0.62) and plagioclase (andesine and labradorite with An48.3-65.1). Phenocrysts set in a fine-grained matrix of the same minerals plus sanidine (Or59.1Ab36.6An4.3) with minor amounts of opaque minerals (magnetite and ilmenite). Secondary minerals are chlorite and calcite. The main textures of these volcanic rocks are porphyritic, microlitic porphyritic, poikilitic, and glomeroporphyritic. The Eocene volcanic rocks of the Khur area are characterized by SiO2 content of 51.8 to 54.9 wt