Metamorphic Phases of Deh Salm Complex in East ofIran
The Deh-Salm metamorphic complex is in vicinity Lut desert 50 km west of Nehbandan southern part of Khorasan province. The complex is consisting of metamorphic rocks, granite, and pegmatite and quartz veins. The protolith of metamorphic rocks is sandstone, claystone, carbonate, basaltic laves and doleretic dikes. Granitic batholiths are Shahkooh, leucocrate batholiths in the east, and intrusive stocks in the metamorphic complex. Field and microscopic data obtained in this study shows that the metamorphism in the Deh-Salm complex occurred in three stages. First Metamorphic phase is related to regional metamorphism with medium pressure and temperature (Barrovian Type). The second phase formed at time of injection of granitic stocks cases, low to medium pressure and high temperature (Abucuma type) which upgrade to appear upper Silimanite zone. Appearance of pegmatite veins and stocks show that probability partial melting have been occurred in crust due to this phase of metamorphism. Third phase of metamorphism was occurred in the Deh-salm complex due to injection of leucocrate granitic stocks is the eastern part of the area. The aureole contains metasandstone, calcschist and skarn. Thermobarometry of skarn shows temperatures and pressure are in rang of 450 to 520 oC and 2.2 to 2.5 kbar respectively.