%0 Journal Article
%T Geochemistry, Paragenesis, and Wall-Rock Alteration of the Qatruyeh Iron Deposits, Southwest of Iran: Implications for a Hydrothermal-Metasomatic Genetic Model
%A Sina Asadi
%A Mohammad Ali Rajabzadeh
%J Journal of Geological Research
%D 2014
%I Hindawi Publishing Corporation
%R 10.1155/2014/590540
%X The Qatruyeh iron deposits, located on the eastern border of the NW-SE trending Sanandaj-Sirjan metamorphic zone, southwest of Iran, are hosted by a late Proterozoic to early Paleozoic sequence dominated by metamorphosed carbonate rocks. The magnetite ores occurred as layered to massive bodies, with lesser amounts of disseminated magnetite and hematite-bearing veins. Textural evidences, along with geochemical analyses of the high field strengths (HFSEs), large ion lithophiles (LILEs), and rare earth elements (REEs), indicate that the main mineralization stage occurred as low-grade layered magnetite ores due to high-temperature hydrothermal fluids accompanied by Na-Ca alteration. Most of the main ore-stage minerals precipitated from an aqueous-carbonic fluid (3.5¨C15£¿wt.% NaCl equiv.) at temperatures ranging between 300¡ã and 410¡ãC during fluid mixing process, CO2 effervescence, cooling, and increasing of pH. Low-temperature hydrothermal activity subsequently produced hematite ores associated with propylitic alteration. The metacarbonate host rocks are LILE-depleted and HFSE-enriched due to metasomatic alteration. 1. Introduction The last decade has seen major progress in our understanding of the origin of iron ore deposits worldwide. The majority of interpretations focused on the igneous iron oxide deposits either having formed by magmatic liquid immiscibility [1¨C7] or by hydrothermal alteration and replacement [8¨C14]. The hydrothermal iron deposits generally are found at many locations around the Pacific basin, Central America, Australia, and Japan [15]. They are commercially far less important as global source of iron than banded iron formations and igneous iron deposits, except for many countries without these types of iron deposits. Genetic models for hydrothermal Fe-oxide deposits associated with hybrid magmatic to nonmagmatic fluids, which locally mix at the trap site [16], suggest that metamorphic processes or a primary felsic to intermediate intrusion could be regarded as source of the majority of hydrothermal fluids and metals [17, 18]. Therefore, metasomatic iron-rich fluid regimes are associated with magmatism or metamorphism, or both. Depending on the physicochemical conditions the protore iron mineralization could consist of magnetite or hematite, or a mix of the two. They occur in different tectonic environments, such as intracontinental terranes associated with anorogenic magmatism, continental arc terranes, and metamorphic belts [18¨C20]. The most favorable area for hydrothermal ore deposits in Iran is the Sanandaj-Sirjan zone (SSZ), which
%U http://www.hindawi.com/journals/jgr/2014/590540/