Document Type : Original Research Paper

Authors

Department of Geology, Tarbiat Modares University, Tehran, Iran

Abstract

Azna tungsten (copper) ore occurrence is located 2 km west of Azna, in Lorestan province. The region is placed in Sanandaj-Sirjan structural zone of Iran, at the complex deformation sub-zone. In this area, tungsten-copper mineralization occurs as stratiform-stratabound in mylonitic meta-rhyolite and semi-pelitic country rock within upper Triassic volcano sedimentary sequence. The sequence consists of meta-rhyodacite, amphibolite (basic meta-volcanic), black schist, meta-rhyolite and pelitic schist with a predominance of volcanics over sediments. Ore mineral textures cover a wide variety from laminated, disseminated, choloform, bounded to open space filling. Mineralization occurs in several stages concentrated through regional (medium to high grade facies) metamorphism, folding and mylonitization of shear zone (ductile) and fractures of brittle deformation events. In this ore occurrence, metamorphism and deformations process had confused detection of proximal or distal mineralization. But base of comparison of Azna tungsten mineralization with both typical proximal on Felbertal and Austroalpine and distal on Broken Hill and Kleinarltal tungsten mineralizations has shown that they are more similar to the proximal mineral deposits.  

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