Tectonomagmatic evolution of Jurassic calc-alkaline volcano-sedimentary complex by Mineralogical constraints of pyroxenes in Sanandaj-Sirjan Zone, southwest of 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.

کلیدواژه ها:

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