Mineral chemistry of tourmaline and comparison of its types in pegmatites of Zamanabad Area, Hamadan province

Zamanabad area is located in southern of Hamedan Province and belong to Sanandaj-Sirjan magmatic-metamorphic Zone. Lithologic units of this area comprising slate, phyllite, andalusite-garnet bearing schists, metamorphic complex including sillimanite bearing schists, hornfels, pegmatitic unit and recently alluviums. The most important of geological unit is Alvand granitoid pluton at age middle Jurassic. Presence of tourmalines with brown-green pleochroism and blue automorphic tourmalines such as indicolite is the specific features of tourmalines of Zamanabad area. Based on the microprobe analysis and multiple diagrams on tourmalines, the combination of tourmaline in granitic pegmatite is schorl and a few close to foitite. By the way, tourmalines in hornfels pegmatites are schorl and close to dravite. It was studied that tourmaline in granite pegmatites is alkaline and empty site whiles tourmaline in hornfels pegmatite is alkaline. Features such as automorphism, absence of chemical zoning, Al, Fe/Fe+Mg increase and decrease in X-site and host granite lack of Li and pegmatite and aplite related its show that these tourmalines have magmatic origin.Also, alkaline, without of X-site and further amount of Mg and a lesser amount of Al and Fe/Fe+Mg in tourmalines of hornfels pegmatites compatible to metapelites poor of Ca, metapesamites and tourmaline–quartz rocks show this complex have hydrothermal origin.