Economic Geology
Seyed Mehran Heidari; Sara Safavy; Afshin Akbarpour; Azra Hassanlou; Bahram Mohaghegh
Abstract
Saveh-Razan copper (± gold) area, with WNW direction in the northwest of Urmia-Dokhtar magmatic belt, with the highest reaction to right-sided shear zones and structural trend change during the Oligomyocene, leads to the placement of semi-deep Oligomyocene diorite massifs in shallow rock depths. ...
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Saveh-Razan copper (± gold) area, with WNW direction in the northwest of Urmia-Dokhtar magmatic belt, with the highest reaction to right-sided shear zones and structural trend change during the Oligomyocene, leads to the placement of semi-deep Oligomyocene diorite massifs in shallow rock depths. It is an Eocene volcano. By creating different types of mass-related hydrothermal alteration (propylitic, intermediate-advanced argillaceous, and phyllite) along the fractures, the system concentrates the mineralizations in quartz-sulfide veins, hydrothermal incisions, and concentrated sulfide-bearing filaments. Common features of metallurgy in this area are fluid homogenization temperature between 250 to 350 ° C and salinity range of 6-28% by weight of salt, containing CO2 gas and liquid phase of liquid and the presence of sulfides such as pyrite, chalcopyrite, burnite, chalcocite and sulfosalts in related reserves. There is also more gold than silver. Therefore, these features are most similar to the mass-related intermediate-type epitermal deposits that form in calcoalkalkene magmatic arcs.
Economic Geology
maryam sadat lajouei kalaki; Afshin Akbarpour; Alexandre Tarantola; Shohreh Hassanpour; Behzad Mohammadi; Monireh Poshtkoohi
Abstract
The Gheshlaghe mil deposit is located in the Urumieh-Dokhtar magmatic belt. Vein- type mineralization is concordance within the rhyodacitic and rhyolite meta-tuff with Eocene age. Alteration zones of sericite, silica, argillic and iron oxides are observed in the investigated area. Primary sulfide minerals ...
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The Gheshlaghe mil deposit is located in the Urumieh-Dokhtar magmatic belt. Vein- type mineralization is concordance within the rhyodacitic and rhyolite meta-tuff with Eocene age. Alteration zones of sericite, silica, argillic and iron oxides are observed in the investigated area. Primary sulfide minerals of pyrite, fine-grained chalcopyrite and Oxidized specularite and Secondary minerals goethite, limonite, malachite and quartz in Microscopic and field studies have been identified. Based on X-ray diffraction analysis studies minerals such as chlorite, illite, kaolinite, hematite, quartz, mica group and calcite have been observed in the bearing gold veins. According litho-geochemical studies, the gold element has a positive correlation with iron, molybdenum, nickel and lead. A number of 157 fluid inclusion studies in the Gheshlaghe Mil ore mineralization area has been showed mineralization temperature of 99 to 299 °C, rate of salinity ore deposit 1.81 and 12.30 equivalent to the Nacl weight percent. Using Raman laser studies (13 points), the presence of gaseous phases (CO2, N2, H2O) in the fluid inclusions have been demonstrated. Regarding to studies have been done in this area, the Gheshlaghe Mil ore mineralization can to know to a vein type- hydrothermal bearing gold-copper ore deposit.
Economic Geology
afshin akbarpour; Masoud Moslehi
Abstract
Yapal iron ore body is located in northwest of Sanandaj-Sirjan zone. A complex of Paleozoic metamorphed rocks including green schist, mica schist, chlorite schist with green schist facies degree, plus skarn and marble outcrop in this area.. Iron mineralization generally occurs as magnetite with the shapes ...
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Yapal iron ore body is located in northwest of Sanandaj-Sirjan zone. A complex of Paleozoic metamorphed rocks including green schist, mica schist, chlorite schist with green schist facies degree, plus skarn and marble outcrop in this area.. Iron mineralization generally occurs as magnetite with the shapes of lentoid, veins, veinlets and dots in garnet schist and greenschist and near marble outcrop in area. Ore textures are observed as dispersed, stock, replacement and network like. The iron oxide grade varies between 30 to 60 percent. Iron element negatively correlates with sulfur and positively correlates with titanium, magnesium, manganese and the other main oxides. Based on the relation between cobalt and nickel, this ore body is located within hydrothermal-originated category. Some samples are located in the hydrothermal-volcanogenic boundary. Based on distribution patterns of rare earth elements, Yapal iron ore has more similarities with skarn type mineralizations. Geochemical evidences of magnetite and the variations of cobalt, nickel, silica and aluminum suggest the skarn origin for Yapal iron ore. That means the iron has been mobilized by the hot fluids originated by intrusive stocks and precipitated in contact of metamorphic and marble units.
Economic Geology
iman shojaian; A. Akbarpour; Khalil Baharfirouzi; Majid vanaei
Abstract
The Darreh Rahim Iron deposit occurred in 2km northwest of Ghohroud village, 25 km south of Kashan city, in Ghamsar county suburb, Isfahan province, on Urumyeh-Dokhtar magmatic belt. . Based on the petrography data, the main intrusive body of the district has medium to coarse granular texture and granodiorite ...
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The Darreh Rahim Iron deposit occurred in 2km northwest of Ghohroud village, 25 km south of Kashan city, in Ghamsar county suburb, Isfahan province, on Urumyeh-Dokhtar magmatic belt. . Based on the petrography data, the main intrusive body of the district has medium to coarse granular texture and granodiorite rock composition. Injection of this intrusive body in the Cretaceous age limestone caused the formation of skarn processes and related Iron mineralization. An assemblage of pyroxene, chlorite, garnet, calcite and quartz are the main components of skarn and also gang minerals of the ore. Also all evidences of mineralogy, structure and texture, geochemistry and tectonic setting and Ni/(Cr+Mn)toTi+V andCa+Al+Mn toTi+V diagrams showed a similarity of the DarrehRhim ore deposit to Iron-Copper mineralization.
H. Azizi; A. Akbarpour
Abstract
Volcanic rocks with mainly andesite composition and lenzoid form outcropped in the Eocene sedimentary host rocks in the east of Sanandaj. Field studies confirm that they are intercalation with the sedimentary host rocks. In thin section, those have porphyritic, glomoroporphyric microlithic and microlithic ...
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Volcanic rocks with mainly andesite composition and lenzoid form outcropped in the Eocene sedimentary host rocks in the east of Sanandaj. Field studies confirm that they are intercalation with the sedimentary host rocks. In thin section, those have porphyritic, glomoroporphyric microlithic and microlithic porphyric textures. Some texture evidences such as glassy inclusion in the center of plagioclase phenocrysts, displacement of plagioclase and mafic phenocrysts with mafic hydrate minerals imply amalgamation of volcanic activity with soft sediments in shallow water; also cracking of plagioclase phenocrysts confirms this subject. Geochemical study shows that these rocks are enriched in incompatible elements such as U, Th, Pb and depleted in Nb, and Ti elements compared with chondrites, primitive mantle and NMORB. If crustal contamination can be responsible for these changes, but as usual these anomalies imply the primary magma generated above the subduction zone. This volcanic rock may have a unique origin the same as Urumieh-Dokhtar volcanic belt.
A. Akbarpour; N. Gholami; A. Saiedi
Abstract
The masjeddaghi area with 8.5 km2 extent is located in 35 km for east of jolfa.The geological exploration started in this area in 2003 and soil sample method was chosen due to the geological situation topography and weathering ,The sampling network was 100m*100m and 100m*200m ...
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The masjeddaghi area with 8.5 km2 extent is located in 35 km for east of jolfa.The geological exploration started in this area in 2003 and soil sample method was chosen due to the geological situation topography and weathering ,The sampling network was 100m*100m and 100m*200m and all samples were analyzed for 13 elements .including Au,Cr,Co,Ba,Cu,Pb,Zn,Ag, Be, Mo,Sn,Mn.The geological studies shows that the oldest rock unit outcropped is Eocene flysh widely distributed in southern and north eastern part of the area .Another outcrops are mainly volcanic ,subvolcanic complex of andesite and trachyandesite, quartz monzonite and agglomerate(oligomiocene).
In this area brecciated veins of barite – silicious and Cu,Pb,Zn sulfids and various pyrite type of mineralization have been identified. data processing have been carried out for analytical results(comparing main and duplicated samples data),and indicate normal distribution for Ni,Be ,Mn log distribution for other elements.That these two analysis method s,factor analysis and correlation matrix analysis (using standardizing the datas (x-x/s))have been consictent.
Regarding The composite haloes,the result of studies indicate Au,Ag,Be anomalies in eastern part of the area and Cu,Mo anomalies in western part of ARPACHAI valley. considering the lithology and its relation to geochemical anomalies of the area, probable presence of porphyric Cu mineralization in eastern part and epithermal high sulfide Au mineralization in quartz-barite veins are identifid,