The role of magma mixing and crustal components in generation of the Eocene volcanic rocks in north Barzabil area, southeast Tarom range

The investigated area comprise of the Eocene volcanic rocks with basaltic andesite, andesite, trachy andesite, trachyte-trachydacite to dacite and rhyolite-ignimbrite in compositions. These rocks exhibit evidences of magma mingling-mixing including basic-intermediate inclusions enclosed by acidic matrix and plagioclase phenocrysts which display sieve texture, honeycomb structure, oscillatory zoning and dissolution margin. They show calc alkaline, shoshonitic and subduction signatures. The normalized REE patterns and spider diagrams of basic-intermediate lavas follow continental arc and those patterns of acidic rocks overlap with the patterns of peraluminous rhyolite and upper crust. It seems that the basic-parental magma produced from partial melting of asthenosphere which consequence sub continental lithospheric mantle delamination. The parental magma accumulated in the upper crust and produced partial melting of crust and acidic magma. Contamination of parental magma with crustal components and mingling and mixing with acidic magma, have important roles in diversity of the compositions of the investigated volcanic rocks.