بررسی همیافتی کانی‌های زوئیزیت و کلینوزوئیزیت در سنگ‌های دگرگون؛ مثالی از اپیدوت-آمفیبولیت‌های جنوب سلماس- شمال غرب ایران

Zoisite and clinozoisite are coexistent in the Salmas epidote- amphibolites, NW Iran. The frequency of zoisite is higher than clinozoisite in the studied epidote- amphibolites. The pistacite content of zoisite is lower than clinozoisite. XPs in zoisite is about 6.46-10.65% while for clinozoisite it is about 16.72-18.73%. Al-Fe3+ substitution was effective to create the mineral compositional changes in the Salmas epidote group minerals. Composition of coexisting zoisite and clinozoisite is a function of pressure, temperature and whole rock composition. According to zoisite and clinozoisite phase relations and compositions, epidote- amphibolite metamorphism in the Salmas area occurred at temperature of 500±20 ◦C and pressure of 6.5-7 Kbar conditions.