Journal de géologie et géophysique
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Petrology of the Metabasites of Dezg Ophiolite Melange Complex, South-East of Qayen

Zohreh Esmaeili, Gholamreza Fotoohi Rad, Mohammad Hossein Yousefzadeh

The study area is located in southwest of Qayen and in Northern part of Sistan suture zone in east of Iran and it is in real a ophiolitic complex with approximate complete sequence and with a special metamorphic zone including metabasite rocks such as greenschist, epidote amphibolite, amphibolite and granulite in its eastern part. The metabasite rocks are associated to ophiolite, have been affected by low to high grade dynamothermal regional metamorphism that has out cropped as a special metamorphic zone in eastern part of ophiolite. On the base of geochemical diagrams most of these metamorphic rocks are result of dynamothrmal regional metamorphism of primary pillow basaltic lavas and magmatic series of metabasite protoliths, is tholeiitic to high Fe tholeiitic. This composition is showing their relationship with MORB origin magma. The thermobarometric investigations has done on these rocks with varieties of methods, are showing that these metamorphic rocks have been affected by metamorphism in maximum pressure of 3.9 – 5.3 Kbar and maximum temperature of 725 ± 25 degrees of centigrade and in most extensive metamorphic position, changing of metamorphic pressure has had an important effect in parageneses changes.