ترکیب تورمالین در پگماتیت‌های چاه رویی، جنوب غربی نهبندان

The Chah ruii area in southwest of Nehbandan contains two types of tourmaline pegmatites. Type one (type CH) pegmatites are found in the granitoid body and type two (type D) pegmatites in metamorphic rocks around the granitoid. Based on petrography and electron microprobe analyses these tourmalines show schorl- dravite, and located in alkali groups and have high Al contents and deprotonation-substitution and alkali- substitution. The spider and REE diagrams in tourmaline indicate that both groups have similar patterns but the  rate of trace elements are different, and the reason for  more rate of trace elements in tourmaline CH type are setting in granitoid rocks. Then, based on analytical studies, it appears that tourmalines form by interaction of postmagmatic/ residual or hydrothermal fluids related to Chah ruii granitic magma with Deh Salm metamorphic rocks. Temprature variations in formation of mineral types in the pegmatites are very important.