Naeim Emami - Soil Conservation and Watershed Management Research Department, Chaharmahal and Bakhtiari Agricultural and Natural Resources Research and Education Center, AREEO,Shahrekord, Iran

The Jurassic volcano - sedimentary complex in the Zagros Mountains within the central part of the Sanandaj- Sirjan structural zone (southwest of Iran) is composed of volcanics (basalts, andesitic basalts and andesites), subvolcanics (dolerites and microdiorites), volcaniclastics (tuffs, lapilli tuffs, agglomerates, volcanic breccia and tuffites). These igneous rocks have outcropped in Middle Kimmerian Orogenic phases. These rocks with calc-alkaline to tholeiitic affinity representing an island arc system and have originated from upper mantle lherzolites by ۳۰% partial melting in a depth of about ۴۵km. Base on geothermobarometry of the pyroxenes, The basalts have crystallized in temperature of ۱۲۱۵ to ۱۳۸۳ ◦C and pressure of approximately ۱۱.۲۵ to ۱۲.۸ kbar representing a depth of about ۴۱ to ۴۵ km.

Volcanic rocks, Jurassic, Sanandaj-sirjan zone, Tectonomagmatism, Geothermobarometry.