University of Isfahan Petrological Journal 2228-5210 4 13 2013 03 21 Petrography and mineral chemistry of Eocene dykes from Kuh-e-Kam Khashak (North of Khur, Isfahan province) Petrography and mineral chemistry of Eocene dykes from Kuh-e-Kam Khashak (North of Khur, Isfahan province) 19 32 16128 FA Hamideh Abbasi Ghodrat Torabi گروه زمین شناسی دانشگاه اصفهان Journal Article 2016 06 14 Ku-e-Kam Khashak is located in the NE of Isfahan (North of Khur). Basic dykes trending NE-SW and intermediate dykes with NW-SE trend cross cut the Upper Cretaceous sandstone, limestone and marl. The intermediate dykes are much more abundant and widespread in the area. Field studies show that the basic dykes cross-cutting the intermediate dykes, indicating that intermediate dykes are older. Primary minerals of the basic dykes are olivine (chrysolite), clinopyroxene (diopside, augite), plagioclase (labradorite, oligoclase), sanidine, magnetite, orthopyroxene (enstatite), spinel, phlogopite and secondary minerals are zeolite (natrolite and mesolite), chlorite, calcite and serpentine. The intermediate dykes are composed of clinopyroxene (diopside), plagioclase (labradorite), sanidine, mica (biotite and phlogopite), amphibole (magnesio-hastingsite) and magnetite as primary minerals and chlorite and calcite as secondary minerals. Basic dykes have xenocrysts of quartz and xenoliths with pyroxenite and hornfels in composition. Mineral chemistry of clinopyroxenes reveals pressure less than 5 kbars and variable PH2O for the formation of these phases. Thermometry of the micas in intermediate dykes show 732- 747 °C, whereas the biotites of basic dykes crystallized 699 to 808 °C. Petrography and mineral chemistry of the studied dykes indicate sub- alkaline and calc- alkaline characteristic of the primary magma and their magmatic arc setting. Ku-e-Kam Khashak is located in the NE of Isfahan (North of Khur). Basic dykes trending NE-SW and intermediate dykes with NW-SE trend cross cut the Upper Cretaceous sandstone, limestone and marl. The intermediate dykes are much more abundant and widespread in the area. Field studies show that the basic dykes cross-cutting the intermediate dykes, indicating that intermediate dykes are older. Primary minerals of the basic dykes are olivine (chrysolite), clinopyroxene (diopside, augite), plagioclase (labradorite, oligoclase), sanidine, magnetite, orthopyroxene (enstatite), spinel, phlogopite and secondary minerals are zeolite (natrolite and mesolite), chlorite, calcite and serpentine. The intermediate dykes are composed of clinopyroxene (diopside), plagioclase (labradorite), sanidine, mica (biotite and phlogopite), amphibole (magnesio-hastingsite) and magnetite as primary minerals and chlorite and calcite as secondary minerals. Basic dykes have xenocrysts of quartz and xenoliths with pyroxenite and hornfels in composition. Mineral chemistry of clinopyroxenes reveals pressure less than 5 kbars and variable PH2O for the formation of these phases. Thermometry of the micas in intermediate dykes show 732- 747 °C, whereas the biotites of basic dykes crystallized 699 to 808 °C. Petrography and mineral chemistry of the studied dykes indicate sub- alkaline and calc- alkaline characteristic of the primary magma and their magmatic arc setting. https://ijp.ui.ac.ir/article_16128_4863e51cde568286760c64650e05c65a.pdf