QE458 : Geology, mineralogy, geochemistry and genesis of the Gollehchili copper deposit, South of Damghan
Thesis > Central Library of Shahrood University > Geosciences > MSc > 2018
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Abstarct: Qollehchili copper deposit is located in175km south of shahrood at Semnan province, in the northeast part of the Central Iran structural zone. Lithological units in the study area, including; Submarine lava with composition of andesite, andesite-basaltic and dacite, pyroclastic units including; andesitic to basaltic andesite tuff and lithtic tuff and monzodiorite. According to the geochemical studies, igneous rocks are of the calc-alkaline nature and mextaluminous, and formed in the subduction basins related to the volcanic arc. Argillic, sericitic, epidotic and silicic are most alterations in the region. baxsed on field evidence, mineralogy and geochemistry, there are two different types of mineralization in the Qollehchili area: 1) mineralized silicic veins that are hosted with monzodiorite masses and andesitic lava. In thise mineralization type are observed Chalcopyrite, Pyrite, Gallon, and Sphalerite Hyposion, Chalcocyte, Covilite, Malachite, Hematite, Goethite and Limonite Supersion ore, gangue materials are quartz, Calcite and Clay materials.The main structure dominant are vein-veinlets and open space-filling, and the texture dominant include vein-veinlets, open space-filling, disseminated, colloform and replacement of this mineralization. Cu, Pb, and zinc amounts are 2.7, 0.27, 0.66, respectively and Au 18 ppb, that copper and lead grades are significant. In the pattern of rare earth elements, the mineralogical veins where the composition of the primary mantle and the chondrite is normalized the LREE / HREE enrichment and the strong negative Eu anomalies. Fluid inclusions micro-thermometry studies upon coexist quartz with vein Mineralization display that the temperature homogenization amounts is 140° to 266 °C (average 143°C). The salinity of ore-forming fluids vary from 0.7 to 10.61 Wt % NaCl (4.9%). baxsed on temperature homogenization and salinity, Copper mineralization occurred on 4 pressure less than 50 bars and depth about Less than 400 m. 2) Copper mineralization with andesitic rock to andesite-basaltic rocks: The host rocks of this type of mineralization have a red to purple brown color with an andesite to andesite-basaltic composition. Calcocyte and pyrite from Hyposion minerals and colocytic, covellite, malachite, azurite, chrysocolla, hematite, goethite and limonite are Supersion minerals and gangue materials are plagioclase, amphibole, clay minerals, quartz and calcite. The main structure dominant are vein-veinlets and open space-filling and the texture dominant include vein-veinlets, open space-filling, disseminated of this mineralization. Copper is the only mineral element and its content is 2.7 %. In the rare earth element pattern, that
normalized to the composition of the primary mantle and the chondrite, there is enriched LREE / HREE and the strong positive Eu anomalies. baxsed on evidence of geology, mineralogy, geochemistry and fluid inclusions of mineralized silica veins in the Qollehchili region with are similar type of hydrothermal vein and copper mineralization with are similar andesite to andesite-basaltic rock with Volcanic Red Bed.
Keywords:
#Mineralogy #Geochemistary #Fluid inclusion #Vein copper #Volcanic Red Bed #Qollehchili Link
Keeping place: Central Library of Shahrood University
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Keeping place: Central Library of Shahrood University
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