Economic Geology
Mehdi Moradi; Ebrahim Tale Fazel
Abstract
Mouchesh gold deposit (0.7 Mt @ 1.3 g/t gold) is located in the Takab-Delijan gold belt. Mineralization with several 28 gold-bearing quartz-sulfide veins (N40E-trending, 1 to 10 m wide, and 5 to 200 m long) has been formed in the host of Lower Cretaceous andesite and andesitic lithic tuff units. Open ...
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Mouchesh gold deposit (0.7 Mt @ 1.3 g/t gold) is located in the Takab-Delijan gold belt. Mineralization with several 28 gold-bearing quartz-sulfide veins (N40E-trending, 1 to 10 m wide, and 5 to 200 m long) has been formed in the host of Lower Cretaceous andesite and andesitic lithic tuff units. Open space-filling, comb, and disseminated textures are important mineralization textures that were formed in quartz-sulfide±gold veins (vein I) and quartz-barite-galena (vein II), which and cut later by carbonate veins (vein III). The homogenization temperature (Th) and salinity of the fluid inclusions, respectively, with an average temperature of 180 °C and salinity of 0.2 wt% NaCl eq. (vein I), 155 °C and 1.6 wt% NaCl eq. (vein II), and 135 °C and 1.5 wt% NaCl eq. (vein III). The values of δ34S in sulfide minerals of veins I and II are between +0.1 to ‒3‰ (δ34SH2S between ‒0.3 to +0.4‰), which indicates a single magmatic source for sulfur. The results of this research reveal that the existence of hydrostatic conditions (e.g., boiling) in the Mouchesh deposit has caused H2S releasing from the hydrothermal fluid, the decrease in the solubility of the bisulfide complex Au(HS)‒2, and ultimately the gold instability.
Economic Geology
Ebrahim Tale Fazel
Abstract
Study of carbon-oxygen isotopic variations in the gangue carbonate minerals and related host rocks has an important role in identifying carbonate hosted lead and zinc deposits and its mechanism of sulfide ore formation. The yellow color dolostone unit attributed to the Shotori Formation with the Middle ...
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Study of carbon-oxygen isotopic variations in the gangue carbonate minerals and related host rocks has an important role in identifying carbonate hosted lead and zinc deposits and its mechanism of sulfide ore formation. The yellow color dolostone unit attributed to the Shotori Formation with the Middle Triassic age is the main host of sulfide mineralization which deposited on the shale horizon attributed to the Sorkh-Kuh Formation. Galena, sphalerite, pyrite and silver-bearing sulfosalts are the most important sulfide ore minerals in the area, which were formed accompanied with the first (Cal-1) and second (Cal-2) generation calcites. Based on the results of carbon-oxygen isotope data, δ13C and δ18O values in Cal-1 varies from -3.2 to -0.7 ‰ and 12.9 to 14.6 ‰, respectively; and δ13C and δ18O values in Cal-2 varies from -7.3 to -4.4 ‰ and 13.7 to 16.4 ‰, respectively. The carbon-oxygen isotopic composition in the dolostone host rock with compared to calcites has a higher δ13C content (varies between -3.2 to 2.9 ‰) and a wider δ18O range (varies between 22.6 to 28.8 ‰).
Economic Geology
Zafari Zafar Abad; Ebrahim Tale Fazel; Mehrdad Barati; Abbas Oroji
Abstract
The Yenganli gold deposit is one of the important indices of the Takab orefeild is located in the southern Zarshuran deposit and 42 km north of Takab Province. Based on structural subdivision of Iran, this deposit is situated between the Sanandaj-Sirjan zone and Uremia-Dokhtar magmatic arc and is related ...
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The Yenganli gold deposit is one of the important indices of the Takab orefeild is located in the southern Zarshuran deposit and 42 km north of Takab Province. Based on structural subdivision of Iran, this deposit is situated between the Sanandaj-Sirjan zone and Uremia-Dokhtar magmatic arc and is related to sedimentary-hydrothermal activities of the Takab orefield. The Yeganli deposit in the western part of the NW-SE-trending Iman Khan anticline and is similar to the Zarshuran deposit is composed of three Neoproterozoic lithostratigraphic unites, including, schist and serpentinite (Iman-Khan unit), limestone and dolomite (Chaldagh unit) and black shale and siltstone (Zarshuran unit). Mineralization occurs as vein-type, disseminated and breccia with a NNE-trending and 5 km2 thickness in the Zarshuran shale and siltestone and Chaldagh limestone host rocks.
Razieh Rezaei Hamid; Ebrahim Tale Fazel; Shojaedin Niroomand
Abstract
The Baharieh copper deposit with 1 Mt Cu ore, is located in 30 km of NE Kashmar city and it’s belong to Sabzevar zone and Taknar metallogenic area. The copper mineralization as stratabound and 200m length with east-west trending which occurs in porphyric andesitic tuff (middle Eocene). Volcanic ...
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The Baharieh copper deposit with 1 Mt Cu ore, is located in 30 km of NE Kashmar city and it’s belong to Sabzevar zone and Taknar metallogenic area. The copper mineralization as stratabound and 200m length with east-west trending which occurs in porphyric andesitic tuff (middle Eocene). Volcanic to subvolcanic rocks are composed of andesite, dacite and rhyolite and shows calc-alkaline to shoshonitic affinities. According to geochemistry of immobile trace elements (e.g., La, Yb and Zr), the igneous rocks straddle within active continent margin arcs. The vein minerals consist of main sulfide minerals such as chalcopyrite and pyrite, which accompanied with bornite, covelline, and chalcocite. Silicic, calcitic, chloritic and argillic are the main alteration assemblage with mineralization. Two types of fluid inclusions including of liquid-rich (LV-type) and vapor-rich (VL-type) are distinguished in quartz-ore stage of the Baharieh deposit. Homogenization temperature and salinity are recorded varies from 187 to 356°C and 0.99 to 18.7 wt% NaCl eq. Some characteristic as vein, breccia and vuggy textures, volcanic host rocks, low temperature alteration, simple ore minerals and high chalcopyrite content, temperature and salinity of fluids and the other evidences shows Baharieh copper deposit is similar to in Cu (Ag) manto-type (volcanic red bed) deposit at Chile.
E. Tale Fazel
Abstract
The polymetallic Fe (±Base metal, Ag and Au) of northern Kabudan (eastern of Sarborj village), occurs within breccia-porphyry rhyolite and pelitic-schist of the Taknar Formation. Based on field evidence, three rock units including: fine-grain rhyolite (footwall), porphyritic rhyolite (ore horizon) ...
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The polymetallic Fe (±Base metal, Ag and Au) of northern Kabudan (eastern of Sarborj village), occurs within breccia-porphyry rhyolite and pelitic-schist of the Taknar Formation. Based on field evidence, three rock units including: fine-grain rhyolite (footwall), porphyritic rhyolite (ore horizon) and late granitoid-andesitic rocks (hangingwall), are recognized in this area. Lithogeochemical signatures reveal that the fine-grain rhyolite of lower horizon with sub-alkaline geochemical signatures of (Nb/Y<0.7), low Zr/TiO2 (608-930) and Zr/Sc (13.3-36.3) is successive replaced by ore-bearing porphyritic rhyolite with alkaline (Nb/Y>0.7), slightly higher values of Zr/TiO2 (380-1116) and Zr/Sc (22.5-116). Are thought to be the magma thermal control and partial melting of rhyolite in high temperature can be increasing HFSE/compatible element ratio (e.g., Zr/TiO2 and Zr/Sc) and eventually metal occurrence in porphyritic rhyolite are interpreted to have been concentration of ore minerals. Finally, the polymetallic mineralization in northern Kabudan, adjacent to lower rhyolitic unit and ore horizon is probably occurs as a result of lithogeochemical evolution of porphyritic rhyolite felsic rocks.
