Number 40 Volume 10

Open Access Article

1 - Geology, Altration, Mineralization and Geochemical Study in Copper Mine, Gholcheshmeh Area, South of Neyshabor

The Golcheshmeh copper deposit is located in the north-easth of Iran (south of Neyshabour) at the margin of Sabzevar Structural Zone. Based on geological and labratory studies, the outcroped rocks consist of Eocene volcanic rocks such as andesite, basaltic- andesite and More

The Golcheshmeh copper deposit is located in the north-easth of Iran (south of Neyshabour) at the margin of Sabzevar Structural Zone. Based on geological and labratory studies, the outcroped rocks consist of Eocene volcanic rocks such as andesite, basaltic- andesite and basalt, that associated with the sedimentary and volcanosedimentry rocks including limestone, tuff and breccia. The alteration is hosted andesitic layers that includes carbonatization, propylitic and less argilic and sericitic. The carbonatization zone is the most important alteration zone in this area. Mineralization mainly occurs in Eocene or younger volcanic rocks as vein- veinlets, amygdaloidal fillings and some replacement and disseminated styles. According to the minerallographic studies, the main ores containing copper are divided into oxide and sulfide types. Mineralization mainly consists of oxide phases and can be seen as contamination of surface fractures and pores or voids filling in host rocks. The main oxide minerals are malachite, azurite and chrysocolla and sulfide minerals are chalcocite, covellite, with minor chalcopyrite, bornite, digenit and also native copper. Chalcocite is the most abundant sulfide ore in this area. There are probably two generations: The first generation is a primary ore that was formed directly in joints, cracks, and fractures from the ore-containing solution and currently is replaced covellites, and the second generation is chalcocite that was probably formed from the conversion of bornite and chalcopyrite through substitution and under supergene conditions. In most cases, the observed intergrowth between copper ores suggests the multi-stage mineralization in this region. Geochemical studies based on minor and trace elements obtained from this research indicate that the igneous rocks in this region were characterized by the calc-alkaline basalt characteristics and in terms of tectonic setting, could be attributed to subduction zone-related continental arc magmatism. In addition, based on the results of the analyses of trace and rare earth elements, the high amount of Nb (more than 16 ppm), Rb-rich, (Zr / Nb)N (less than 2 and between 0.7 to 0.46), could be an indication of contamination of magma with continental crust. The absence of Eu anomaly suggests a broadly defined melting conditions at oxidation state. On the basis of this study and with respect to some evidences such as tectonic setting, host rock types, structure and texture of ore body, mineral paragenesis, shape of the ore body and associated elements, this area is comparabale to a Manto type deposit located in Chile regardless of some differences. Thus, it is suggested that the Golcheshmeh copper mine classified a Cu- Manto type deposit. Manuscript profile

Open Access Article

2 - Structural Analysis of Fault System of Faroor B Gas Field, Using Modeling and 2D Seismic Reconstruction

In terms of natural fractures, Iranian carbonate reservoirs have a global reputation. These fractures are known as dramatically important factor in the exploration and production of hydrocarbons. Many important oil and gas fields are classified based on the production f More

In terms of natural fractures, Iranian carbonate reservoirs have a global reputation. These fractures are known as dramatically important factor in the exploration and production of hydrocarbons. Many important oil and gas fields are classified based on the production from fractured reservoirs. At the first step, the aim of this study is the investigating the structural evolution of Farour B gas field and then determining how the detected fault influences this gas field. For this study, 2D seismic data, Persian Carpet-2000 (PC-2000), and all related information on the wells of the studied field were collected. Then these data were loaded on Petrel software,. Shifting and interpretation of all the chosen seismic lines were selected according to the excavation information from three wells and finally the deep balanced maps of formations and 3D patterns were provided. The flatting process was done for some seismic sections. According to seismic sections and tectonic analyzing the Farour B structure has two normal faulting trends in which the faults slope are approximately vertical and the eastern and western faults displacement are about 70 meter and 20 meter respectively. Manuscript profile

Open Access Article

3 - Study of retrograde metamorphism in the calc-silicate rocks from the Alvand aureole

The Alvand batholith is intruded into the Jurassic argillaceous and carbonate rocks and has caused contact metamorphism. The calc-silicate hornfelses and varieties of pelitic and mafic hornfelses are produced in this regard. Based on the modal percentage, the calc-silic More

The Alvand batholith is intruded into the Jurassic argillaceous and carbonate rocks and has caused contact metamorphism. The calc-silicate hornfelses and varieties of pelitic and mafic hornfelses are produced in this regard. Based on the modal percentage, the calc-silicate rocks of the area can be divided into different groups. The present study shows that the calc-silicate hornfelses of the Hamadan area are metamorphosed during two metamorphic phases, the prograde and the retrograde events. The prograde metamorphism formed anhydrous minerals such as pyroxene, garnet and vesuvianite. Following this phase, by reduction of temperature the retrograde metamorphism occurred and tremolite-actinolite, zoisite, epidote and to some extent hematite were formed. The rocks resulted from this metamorphism are epidote calc-silicate, epidote-tremolite-actinolite calcsilicate, zoisite calc-silicate and . . . . Retrograde metamorphism caused alteration along the grain boundaries and along the cleavage plane of the minerals (especially garnet). Furthermore, some textures, such as symplectite texture, were developed in the rocks, which is in accordance with decreasing temperature. Manuscript profile

Open Access Article

4 - Morphometric age of Khatoon-Bagh cinder cone, NE of Mahabad, West Azerbaijan province
Morteza Khalatbari Nafiseh Salehi Marzieh Faridi Masouleh

Scoria cone near Khatoon-Bagh, NE of Mahabad in West Azerbaijan province consists of 3 Parts: Lower part containlayer of scoria, ash and tephra, middle part consist of volcanic bomb-bearing scoria and finally (Cupper part) a layer full of bomb. Their composition is main More

Scoria cone near Khatoon-Bagh, NE of Mahabad in West Azerbaijan province consists of 3 Parts: Lower part containlayer of scoria, ash and tephra, middle part consist of volcanic bomb-bearing scoria and finally (Cupper part) a layer full of bomb. Their composition is mainly olivine basalt. The morphometric data used for morphologic age were either derived by manual measurement on topographic maps and by Digital Elevation Model-based (DEM) calculations. The main parameters of cone such as height, basal and crater diameter have been measured for calculation of Hco/Wco ratio and average slope angle. The main parameters show that the basal shape of this cinder cone is elliptical and at the crater is super elliptical, therefore can categorize it as horseshoe-shaped cone. The comparison of main parameters from a number of previous studied cinder cones from around the world suggest that dimensions of Khatoon-Bagh cone is similar to global average. Since with the increase in age and degradation of cone, the height, height to diameter and slope angle of cone will decrease, so Hco/Wco could be used for morphometric ages. According to Wood (1980b) and Sucipta et al. (2006) aging data and Porker (1972)’s relations, the relative age of Khatoon-Bagh cinder cone estimate 0.7-2 Ma which is in agreement with stratigraphic age in geological maps Manuscript profile

Open Access Article

5 - Gold and trace elements distribution in pyrite from the Senjedeh gold deposit Muteh mining district, according to EPMA results
Zahra Nourian Mohammad yazdi Fariborz Masoudi

Muteh district is located in the central part of Sanandaj- Sirjan Zone. It consists of two active mines, including the Chah Khatoon and Senjedeh open pits. Exposed rock units in the area underwent greenschist to lower amphibolite metamorphism. They consist of deformed a More

Muteh district is located in the central part of Sanandaj- Sirjan Zone. It consists of two active mines, including the Chah Khatoon and Senjedeh open pits. Exposed rock units in the area underwent greenschist to lower amphibolite metamorphism. They consist of deformed and metamorphosed volcano-sedimentary and acidic volcanic rocks. Gold mineralization is hosted in metamorphic rocks and pyrite is the most important Au-hosting mineral in the Muteh minig district; therefore, pyrite from the Senjedeh gold deposit was investigated using a combination of ore microscopy, including back-scattered imaging (BSE), and electron probe microanalysis (EPMA) with the aim to investigate gold and trace elements (Se, As, Pb, Bi, Sb, Co, Ag, Te, Zn, Cu, Ni) distribution. Based on our studies, there are two generations of pyrite: medium-grained, anhedral and deformed of first generation of pyrite that is characterized by abundance of microfractures, contains high level of gold ( up to 810 ppm) and coarse grained, euhedral of second generation of pyrite, contains low- medium level of gold (bdl- 110 ppm). Results of this study show that there are no systematic differences between the trace element compositions of two generations of pyrite. According to BSE, visible gold is widespread and present as irregular grains of native gold mostly along grain boundaries or filling microfractures of first generation of pyrite. Element mapping indicates that Co is incorporated in pyrite crystal lattice and shows compositional zoning in pyrite grains. Ultramafic, and to a lesser extent, mafic rocks are typically strongly enriched in Co; in contrast, felsic rocks usually contain low Co concentrations. Therefore, high Co concentrations should be a good indicator of a high proportion of mafic to ultramafic over felsic rocks in the fluid source area. Co concentrations in pyrite ,possibly linked to mafic/ultramafic metamorphic rocks, provide further evidence for the orogenic gold deposit affinity. Manuscript profile

Open Access Article

6 - Mineral chemistry and Petrology of shoshonit gabbroic bodies from the Hashtsar-Leghlan (Hourand-East Azarbaijan)
Alireza Ravankhah Mohsen Moayyed Mehadi Moradi Amir Morteza Azimzadeh Jamshid Hasanzadeh Nasir Amel

The gabbroic bodies are outcropped in the East and south-west of Hourand (East of Kaleybar) and in the East Azarbaijan province. The gabbroic body of Leghlan forms frequent sills injected in the Upper Cretaceous-Paleocene flysch deposits. The gabbroic body of Hashtsar More

The gabbroic bodies are outcropped in the East and south-west of Hourand (East of Kaleybar) and in the East Azarbaijan province. The gabbroic body of Leghlan forms frequent sills injected in the Upper Cretaceous-Paleocene flysch deposits. The gabbroic body of Hashtsar along with associated pyroxenite were injected into these deposits. The mineral composition of the gabbroic body of Leghlan is plagioclase, clinopyroxene, potassium feldspar and biotite, and the major minerals of the gabbroic body of Hashtsar includes plagioclase, clinopyroxene and amphibole. Plagioclases in gabbroic body of Hashtsar (anorthite) is more calcic than those in the gabbroic body of Leghlan and show no chemical zoning. The composition of clinopyroxene in both bodies is in the range of diopside and amphiboles in gabbroic body of Hashtsar are pargasite to tschermakite. The parental magmas of these bodies, based on mineral chemistry and composition of clinopyroxene, was shoshonit and the melting occurred at a rate of about 5% of the enriched spinel-garnet lherzolite mantle and with garnet in the residue. The rocks were developed in a volcanic arc setting. Manuscript profile

Open Access Article

7 - Occurrence of native copper mineralization within the volcanic host rocks of the Garmabe Paein Cu-Ag volcanogenic massive sulfide deposit, southeast of Shahrood
Majid Tashi

The Garmabe Paein copper-silver volcanogenic massive sulfide (VMS) deposit is located 290 km southeast of Shahrood and occurred within the Upper Cretaceous volcano-sedimentary sequence in the Sabzevar subzone, north-east of Iran. Native copper mineralization occurred wi More

The Garmabe Paein copper-silver volcanogenic massive sulfide (VMS) deposit is located 290 km southeast of Shahrood and occurred within the Upper Cretaceous volcano-sedimentary sequence in the Sabzevar subzone, north-east of Iran. Native copper mineralization occurred within the Cretaceous volcanic host rocks of the Garmabe Paein deposit including andesite-basalt with amygdaloidal texture, trachyandesite and volcanic breccia, and Paleocene conglomerate, as vein-veinlets and disseminated forms. Geochemical studies indicate that the volcanic rocks have basaltic compositions and calc-alkaline nature, deposited within a back-arc basin. Major wall rock alterations are dominated by chloritic and minor zeolitic mineralization. This study shows that diagenesis and burial process in the host volcano-sedimentary sequence produced relatively hot and brine fluids which leached copper from the volcanic rocks and deposited as native copper under reduced conditions within the Late Cretaceous andesit-basalt and trachyandesite and Paleocene conglomerate. Considering host rock types, mineralogy and alteration, the native copper mineralization in the Garmabe Paein deposit show most similarity with the native copper mineralization in the basaltic rocks (Michigan-type), which occurred slightly after formation of the Garmabe Paein VMS deposit during diagenesis, burial metamorphism and uplift. Manuscript profile

Open Access Article

8 - Occurrence of native copper mineralization within the volcanic host rocks of the Garmabe Paein Cu-Ag volcanogenic massive sulfide deposit, southeast of Shahrood

The Garmabe Paein copper-silver volcanogenic massive sulfide (VMS) deposit is located 290 km southeast of Shahrood and occurred within the Upper Cretaceous volcano-sedimentary sequence in the Sabzevar subzone, north-east of Iran. Native copper mineralization occurred wi More

The Garmabe Paein copper-silver volcanogenic massive sulfide (VMS) deposit is located 290 km southeast of Shahrood and occurred within the Upper Cretaceous volcano-sedimentary sequence in the Sabzevar subzone, north-east of Iran. Native copper mineralization occurred within the Cretaceous volcanic host rocks of the Garmabe Paein deposit including andesite-basalt with amygdaloidal texture, trachyandesite and volcanic breccia, and Paleocene conglomerate, as vein-veinlets and disseminated forms. Geochemical studies indicate that the volcanic rocks have basaltic compositions and calc-alkaline nature, deposited within a back-arc basin. Major wall rock alterations are dominated by chloritic and minor zeolitic mineralization. This study shows that diagenesis and burial process in the host volcano-sedimentary sequence produced relatively hot and brine fluids which leached copper from the volcanic rocks and deposited as native copper under reduced conditions within the Late Cretaceous andesit-basalt and trachyandesite and Paleocene conglomerate. Considering host rock types, mineralogy and alteration, the native copper mineralization in the Garmabe Paein deposit show most similarity with the native copper mineralization in the basaltic rocks (Michigan-type), which occurred slightly after formation of the Garmabe Paein VMS deposit during diagenesis, burial metamorphism and uplift. Manuscript profile

Open Access Article

9 - Geochemistry of Salafchegan quartz diorite pluton
Mahbobeh Nazari Shahryar Keshtgar Ali Kananian Mohammad Boomeri

The Salafchegan quartz diorite pluton which is located at 45 km southwest of Qom, has intruded sandstone and sandy limestone of the Upper Red Formation as small subvolcanic intrusion. A zigzag pattern of major and trace elements variations in these intrusive rocks, from More

The Salafchegan quartz diorite pluton which is located at 45 km southwest of Qom, has intruded sandstone and sandy limestone of the Upper Red Formation as small subvolcanic intrusion. A zigzag pattern of major and trace elements variations in these intrusive rocks, from margin to the center of the pluton, may indicate periodical magma chamber refreshments. These subvolcanic rocks show geochemical calc-alkaline affinity and in the case of aluminum saturation index, they could be classified as meta-aluminous rocks, similar to I type granitoids. These rocks are enriched in LILE, and LREE but depleted in HREE. In addition, they show negative anomalies of Nb and Ti, low Ce/Pb, high Ba/La and Ba/Th ratios associated with high Al content. They illustrate porphyritic texture accompanied by inequilibrium phenocrysts such as zoned plagioclase or reaction rims surrounding hornblende crystals. Based on petrographical studies and geochemical analysis, it could be suggested that the parent magma of these subvolcanic rocks was related to a subduction zone and has emplaced in a magmatic arc. Manuscript profile

List of Articles