Writers : Zarinkoob,Mohammad hoseyn;Khatib,Mohammad mehdi
Refference : 11th Symposium Of Geological Society Of Iran - Mashhad, Ferdowsi University
Publishing Year : 1386

Abstract :

There are a seri of volcanic and subvolcanic rocks as andesite, microdiorite,and dacite in southern border of Birjand ophiolite melange which cut the oceanic lithospher rocks. They have massive, neck and dome shape and dyke structures. The main texture is porphyric with fine grain groundmass. Plagioclase and hornbelend are the main phenocrysts. Plagioclases are andesin type and have albitic and carlsbad twinning with zoning. Volcanic rocks are located in tentional spaces in compressional-shear zone that occurred as a leftlateral-shear zone. Pressure release in these places has ceated suitable situation for partial melting and decend of magma to the surface. This phenomena indicates a tectonic inversion process in south of Birjand ophiolite melange.