Introduction of the Mood area volcanism as an indicative example of the reproductive diversity of volcanic lavas (northwest of Sarbisheh - east of Iran).

Authors

Department of geology, Payamenoor University, Tehran, Iran.

Abstract

Within an area with the extent of 12km2 in the east and northeast region of Mood City, two distinct lithological outcrops are observed and studied. Trachy basalts with porphyritic texture, hyalopilitic, semi-crystalline to microcrystalline mesostasis, and contain olivines with eroded and gulf margins as prominent mafic phenocrysts, and dacitic lavas, have been studied in their vicinity, which have the dominant porphyritic texture and microcrystallin to glassy mesostasis. They obviously show hypersthene phenocrysts in their microscopic sections. East Mood potassic calc-alkaline continental arc dacitic lavas that have originated from subduction movement and erupted in an active continental margin. Their parental magma is the result of the 20% partial melting of a peridotite-enriched mantle source at 50 Km depth above the subduction zone. There are clear pieces of evidence to confirm crustal contamination as a process that affected their parental melt. Northeast Mood enriched mantle-originated Trachybasalts do not show any signs of crustal contamination and contain a considerable Na2O which can be an expression for sodium metasomatism during the eruption in an extensional geo-structural regime as a shallow intra-continental basin. These lavas belong to the post-collision potassic calc-alkaline rocks that erupted along deep right lateral Strick sleep fault zones related to the Nehbandan fault system in the east of Iran. , Their parental melt affected by a 10% partial melting in the lower part of the lithospheric crust and at the depth of 60 to 80 Km.

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