Economic Geology
Raziyeh Mahabady; Farajollah Fardoost
Abstract
Abgareh copper deposit located in 140 km southwest of shahrood and part of a volcanic-sedimentary Torud-Chah shirin belt that has facies in the northern edge Structural-sedimentary zones of Central Iran. Field and petrographical studies, deposit area, consist of andesite, basaltic andesite and basalt ...
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Abgareh copper deposit located in 140 km southwest of shahrood and part of a volcanic-sedimentary Torud-Chah shirin belt that has facies in the northern edge Structural-sedimentary zones of Central Iran. Field and petrographical studies, deposit area, consist of andesite, basaltic andesite and basalt and contains less includes tuffit crystal that indicate middle–upper Eocene with with argillitic, sericitic, silicic, carbonatic, chloritic and iron oxides alterations. According to the field observations and mineralogical studies, the mineralization in the region was carried out in two stages: hypogene and supergene and weathering. Hypogen zone minerals are generally pyrite, chalcopyrite and bornite. Because of existence in oxidizing-supergene environment , nearly almost Cu-bearing minerals of the main stage of mineralization have been replaced by secondary Cu minerals such as chalcocite, covellite, malachite and chrysocolla. Fluid inclusion data shows in the temperature range from 145 to 217 °C and salinity between 3.73 and 9.84 Wt%NaCl and depths less than 390 m. The host rocks, ore mineralogy, ore structures and textures, and fluid inclusions characteristics and comparison with similar epithelial deposits indicate that the Abgareh vein system is formed in a low-sulfidation epitermal environment.
Economic Geology
faraj fardoost; Akbar Abdollahi Hydarbaghi; Solmaz Baluchi
Abstract
The Robaei Iron deposit is located in 96km south of Damghan. Host rocks of deposit are Late Cretaceous limestones (part I) and Eocene volcano- sedimentary rocks including sandy tuff (part II.( The alterations include chloritization, epidotization, argillation, silicification, carbonatization and hematitization. ...
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The Robaei Iron deposit is located in 96km south of Damghan. Host rocks of deposit are Late Cretaceous limestones (part I) and Eocene volcano- sedimentary rocks including sandy tuff (part II.( The alterations include chloritization, epidotization, argillation, silicification, carbonatization and hematitization. Minerals forming can be divided into three groups; iron minerals (hematite, magnetite, pyrite, pyrrotite goethite and limonite), copper- minerals (chalcopyrite, chalcocite, covellite and malachite) and gangue minerals (calcite, dolomite, quartz, garnet, epidote and chlorite). The structure and textures of ore minerals are massive, vein- veinlet, open space filling and disseminated. In part I, the metals grade of Fet is about 60%, Cu 0.7 % and Au 2.7 ppm and in the part II, the Fet are variables between 5.88 to 82.91% (average 31.2%), Cu between 275 to 20761 ppm and Au 0.89 ppm. Fluid inclusion studies were carried out on quartz mineral from the part II that homogenization temperature is frequency variables between 200 to 249°C with salinity of 2-4% wt. %NaCl. Based on the results of this investigation, part I has similarities with calcic skarn of low temperature and part II showed more similarities with iron oxide- copper- gold (IOCG) deposits.
Economic Geology
yegane khoramtash; farajolah fardoost
Abstract
The Saghari copper deposit is located 120 Km at Southwest of shahrood, within in the eastern part of Toroud-Chahshirin magmatic arc. Mineralization in the Saghari area occured within volcanic and pyroclastic units of Eocene. Based on the field, laboratory investigations and geochemical analysis, the ...
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The Saghari copper deposit is located 120 Km at Southwest of shahrood, within in the eastern part of Toroud-Chahshirin magmatic arc. Mineralization in the Saghari area occured within volcanic and pyroclastic units of Eocene. Based on the field, laboratory investigations and geochemical analysis, the outcropped rocks in the Saghari deposit are andesite, andesite-basalt, basalt, dacite and several exposures of pyroclastic rocks such as tuff and agglomerate. The rocks are high-k, calc-alkaline to a small amount of shoshonitic in nature, and are formed at a magmatic arc setting in a subduction zone. Basic to intermediate dyke bodies intruded Eocene volcanic-pyroclastic sequences. The host rocks have been affected by argillitic, sericitization, chloritzation, carbonatization and oxide-Fe (limonite, hematite and goethite). The textures and structures of mineralization are vein-veinlet, replacement, open space filling and disminated. According to the mineralography studies, main minerals of copper are malachite, chalcocite, covellite, chalcopyrite, chrysocolla and rare native copper. Malachite and chalcosite are the most abundant minerals. Geochemical studies indicate that copper has a relative correlation with silver.also based on studies of fluid inclusion, the depth of the ore, formation temperature and salinity are 100-200 meter, 100-140 °c and 5-15 WtNaCl%. Copper mineralization in the Saghari deposite has similarities in mineralogy, host rock, texture, structure and geometry with manto-type and volcanic red bed copper deposits.
