براورد دما - فشار و گریزندگی اکسیژن در گابرو - پیروکسنیت‌های تازه کند کلیبر؛ با تمرکز بر شیمی بلورها و فعالیت کانی‌ها

In the mafic-ultramafic suite of Tazehkand, Kalaybar-NW Iran, of Early-Cenozoic age, pyroxenitic core is surrounded by gabbro and total complex is surrounded by Paleocene volcano clastic of Majid Abad Formation. The pyroxenite is composed chiefly of Cpx+Ol+Ore. The associated gabbro minerals consist of Pl + Cpx + Am + Phl. The pyroxene composition in the two rock types is diopside-rich and ranges between hedenbergite to Ca-tschermak. Plagioclase is anorthitic type and opaque mineral is mostly hematite. Some results of this investigation on the relationship between major phases activity and mineral chemical composition in these rocks are: Ca-tschermak activity in the pyroxenes is controlled with Al-content in T-site, Tschemakite activity in amphiboles has direct relation with (IV) Al, but reverse relations with (IV) Si, (VI) Al and (A) Na. Using several thermobarometric methods, temperature of 900 ºC for pyroxenites and pressure of 7-9 kbar on the same temperature for gabbro crystallization, are estimated. The temperature of observed ilmenite lamellae exsolution from hematite matrix during sub-solidus phenomena is detected about 470 ºC. Calculated Log fO2 for the source magma is -8 to -14. This quantity is higher for pyroxenites than gabbros.