Exploration and Mining
Saeid Ghasemzadeh; Abbas Maghsoudi; Mahyar Yousefi
Abstract
The Baft district in Kerman province is located in the southeastern segment of the Urumieh-Dokhtar magmatic arc. This arc is characterized by thick accumulations of Cenozoic plutonic and volcanic rocks and provide favorable conditions to the development of hydrothermal systems and mineral deposition, ...
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The Baft district in Kerman province is located in the southeastern segment of the Urumieh-Dokhtar magmatic arc. This arc is characterized by thick accumulations of Cenozoic plutonic and volcanic rocks and provide favorable conditions to the development of hydrothermal systems and mineral deposition, in particular porphyry copper mineralization. For mineral prospectivity mapping (MPM) to delineate prospective areas some individual maps of evidence including distance to intrusive contacts, fault density, distance to hydrothermal alterations and multi-element geochemical signature were generated. Spatial evidence values in each map were transformed using a logistic function of unbounded values into the [0,1] range. Thus continuous maps of fuzzy evidence layers were integrated using geometric average function. To evaluate results of final potential map a data-driven prediction-area was used. The results showed that for the geometric average prospectivity model, 87% of the known mineral occurrences are predicted in 13% of the study area. Hence, this method can be utilized for mineral prospectivity mapping to delineate target areas for further exploration of a certain deposit-type.
Economic Geology
Reza Ghezelbash; A. Maghsoudi
Abstract
Varzaghan district is located in NW of Arasbaran magmatic belt (AMB) which is one of the most highly mineralized region in Iran and host to a significant number of porphyry Cu deposits such as Sungun Cu-Mo porphyry deposit. The main goal of this study is synthesizing diverse raster-based evidence layers ...
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Varzaghan district is located in NW of Arasbaran magmatic belt (AMB) which is one of the most highly mineralized region in Iran and host to a significant number of porphyry Cu deposits such as Sungun Cu-Mo porphyry deposit. The main goal of this study is synthesizing diverse raster-based evidence layers including geochemical, alteration and geological geo-data sets for mineral prospectivity modeling (MPM). For this purpose, firstly, continuous values of six favorable evidential maps as main criteria (geochemical signature of PC1 scores, values of proximity to argillic, phyllic and iron-oxide alterations, values of proximity to Oligo-Miocene intrusions and fault density) were divided into reasonable classes by applying concentration-area fractal model and then discretized layers were integrated using analytical hierarchy process (AHP) and technique for order preference by similarity to ideal solution (TOPSIS) to generate a final map of porphyry Cu potential within the central part of Varzaghan district. Finally, the success-rate curve of the AHP-TOPSIS model as a quantitative evaluation method according to the locations of known Cu occurrences was drawn. Results revealed the successful performance of AHP-TOPSIS model in portraying the prospective areas related to porphyry Cu mineralization.
S Younesi; M.R Hosseinzadeh; M Moayyed; A Maghsoudi
Abstract
The study area is located at the center of the Lut area and the southern part of the Eocene- Oligocene Lut volcano-plutonic belt. The main exposed igneous rocks include widespread and thick units of Middle Eocene volcanic (basaltic andesite, andesiteand trachy-andesite) and Eocene-Oligocene volcanic-subvolcanic ...
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The study area is located at the center of the Lut area and the southern part of the Eocene- Oligocene Lut volcano-plutonic belt. The main exposed igneous rocks include widespread and thick units of Middle Eocene volcanic (basaltic andesite, andesiteand trachy-andesite) and Eocene-Oligocene volcanic-subvolcanic (dacite and rhyodacite) with related tuffs, intruded by microdioritic stock and dykes of Oligocene with gabbrodiorite to quartzdiorite compositions. Texture is dominantly porphyritic and the main minerals are plagioclase, clinopyroxene, hornblende, K-feldspar, quartz and minor amounts of biotite with apatite, zircon, rutile and opaque minerals as accessory phases. These rocks with predominant K-high calc-alkaline to shoshonitic affinities, are I type and metaluminous and are characterized by LILE, LREE and Th enrichment relative to HFSE, depletion in Nb,Ti,Ta and weak depletion in HREE and Y. These features are characteristic of the post-collisional calc-alkaline rocks along with a continental active margin tectonic setting. In spite of the low ratios of Nb/U, Nb/La and Ce/Pb, the Sm/Yb (1.6-2.1) ratio reveals low contamination of magmas with relatively thin crust which is in accordance with low crustal thickness in this area (36-38Km). According to geochemistry of trace elements and REEs, the main cause of magmatism in Mahour was melting of a metasomatized lithospheric mantle (E-MORB like) with spinel lherzolite composition accompanied by very small amount of garnet in the presence of phlogopite. On the basis of the phenocrysts assemblage, REE pattern with negative Eu anomaly (Eu/Eu*= 0.63- 0.9) and also La/Yb calibration to crustal thickness, magmas have undergone relatively dry crystallization in the magma chamber at shallow depths (
A Maghsoudi; M Vanaei; M Vanaei
Abstract
The NekaRiver is located at 21km in east of Sari, center city of the Mazanderan province, north of Iran. 51 stream sediment samples were collected from 4 sample sites. The samples were digested by HF+HClO4+HNO3 and analyzed by AAS in laboratory of Geological Survey of Iran. The results of analysis show ...
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The NekaRiver is located at 21km in east of Sari, center city of the Mazanderan province, north of Iran. 51 stream sediment samples were collected from 4 sample sites. The samples were digested by HF+HClO4+HNO3 and analyzed by AAS in laboratory of Geological Survey of Iran. The results of analysis show that the enrichment ratio and Geo-accumulation index are too high for Ag, Cd and Sn in the whole sediments of the NekaRiver. Zn shows very high enrichment in the sites of Boz Mil and Lajan Lateh Sofla sample sites and Pb shows very high enrichment in the site of Boz Mil. Degrees of Geo-accumulation Index are very high for Ag-Cd in the 4 sites but for Zn are high to medium and for other elements are medium. In the Neka Choob and Mola Khil sample sites, the Co and Ag are too high because of anthropogenic contamination and Fe and Ni are low relatively. In the Boz Mil and Lajan Lateh Sofla sample sites, the Pb and Ag are too high because of anthropogenic contamination and V, Ni, Cu and Zn are low relatively. Coal mining and coal deposition in the upper part of the NekaRiver, urban and wood industry sewage are the main sources of the pollution.
A. Maghsoudi; M. Yazdi; M. Mehrpartou; M. Vosooghi Abedini
Abstract
The Mirkuh Ali Mirza gold mineralization is located in north Sarab in the Western Alborz–Azerbaijan structural zone. Mineralization was formed in the form of a vein occurring in Neogene dacitic and rhyodacitic tuff along a series of NW–SE trending fault; Mineralization associated with quartz-sericite-adularia-calcite ...
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The Mirkuh Ali Mirza gold mineralization is located in north Sarab in the Western Alborz–Azerbaijan structural zone. Mineralization was formed in the form of a vein occurring in Neogene dacitic and rhyodacitic tuff along a series of NW–SE trending fault; Mineralization associated with quartz-sericite-adularia-calcite and pyrite(<1%) assemblages is a typical of low-sulfidation epithermal gold mineralization. The fluid inclusion data from quartz minerals indicate homogenization temperature of 161-260°C and salinities of 0.5 to 6.5 wt% NaCl equiv. The variation in gold grade in quartz vein is 270-3240 ppb. The highest gold content is in lattice and breccias quartz that can indicate direct relationship between boiling to gold deposition. The idea is supported by coexistence of vapor-dominant and liquid-dominant fluid inclusions.
