Thermometry and determine the characterization of magma of Cretaceous acidic rocks using the zircon mineral morphology and compare it with whole-rock chemistry in SE Saqqez, NW Iran

Zircon is an stable mineral during post crystallization processes and preserves characters of magmatic events. Zircon morphology can give some information about temperature, nature, and source of the magma. Study of the zircon morphology of Cretaceous granitoids and acidic volcanics from the southeast Saqqez area reveals that most of the crystals are P5 and S25 types with high alkalinity (I.A.) and temperature indexes (I.T.) in the range of 672.9 and 637.9 respectively.The minimum temperature of zircon crystallization is estimated to be in the range of 600 to 750 °C based on the morphology, saturation of Zr, and whole-rock chemistry. The presence of apatite inclusions and the mineralogical composition indicate that the source of the magma was relatively hydrous. Typological evolutionary trend (T.E.T.) shows the granites as I-type with calc-alkaline nature, which are in line with geochemical data. The zircon mineral morphology indicates that the granites in the SE Saqqez formed from hybrid magma with crustal and mantle origin.