Scientific Quarterly Journal of Geosciences

Scientific Quarterly Journal of Geosciences

Petrological, petrographical and geochemical Study of the plutonic rocks from East of Heris, East Azarbaijan, NW Iran

Document Type : Original Research Paper

Authors
Department of Geology, Faculty of Natural Sciences, University of Tabriz, Tabriz, Iran
Abstract
The study area, a part of Alborz-Azarbaijan zone, is located in about 20 km east of Heris district, NW Iran. The plutonic rocks are diorite, granodiorite, quartzdiorite and quartz-monzodiorite of the Middle-Upper Eocene, intruded into the Eocene volcanic rocks. Magmatic and hydrothermal fluids derived from the magma altered both plutonic and volcanic rocks. The texture of granitoid rocks is granular, porphyritic nicto granular and the rock - forming minerals are plagioclase, alkali feldspar, quartz, augite, hornblende, zircon and apatite. Petrographical studies show that nonequilibrium textures such as acicular apatites, skeletal hornblendes and abnormal zoning in plagioclases can be regarded as evidence of mixing of an acid and basic magma. Field, petrological and geochemical investigations show that the granitoids are I-type, high K, calc alkaline, meta-aluminous and belong to continental arc or post collision arc.
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