Economic Geology
Alireza Zarasvandi; Mohsen Rezaei; Mansour Adelpour; Hadis Parvaneh
Abstract
Parkam (Sara) and Abdar porphyry Cu deposits containing mainly dioritic and quartz dioritic stocks are located in the southern part of Urumieh-Dokhtar Magmatic Belt (UDMB). In the Parkam deposit, alterations such as potassic, potassic-phyllic, biotitic, phyllic, argillic and propylitic have been identified, ...
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Parkam (Sara) and Abdar porphyry Cu deposits containing mainly dioritic and quartz dioritic stocks are located in the southern part of Urumieh-Dokhtar Magmatic Belt (UDMB). In the Parkam deposit, alterations such as potassic, potassic-phyllic, biotitic, phyllic, argillic and propylitic have been identified, while Abdar deposit is characterized by the limited extent of potassic alteration with widespread occurrence of phyllic alteration. The aim of this study is to characterize the phyllic alteration using sericite and sulfide (i.e., pyrite and chalcopyrite) chemistry. In this way representative phyllic alteration samples were analyzed using Electron Microprobe Analysis (EMPA). Results imply for higher concentrations of Zn, Ag, Au, and as in the chalcopyrite samples (averages in wt. %; 0.07, 0.007, 0.012, and 0.043; respectively). Comparably, pyrite samples exhibit higher concentrations of Re, Te, Co, and Mo (averages in wt. %; 0.01, 0.003, 0.09, 0.07; respectively. Among this, gold concentration in the pyrite samples of studied deposits is analogous to those reported previously for Meiduk porphyry Cu-Mo systems wherein gold occurs as inclusions, and/or nanoparticles (probably as Au0 or Au-telluride). In the both deposits, fine-grained micas are K-rich. Additionally, sericite samples exhibit an increasing trend of Si with Fe2+, Mg2+, and Al3+ substitution in the octahedral sites confirming the changes to celedontie - endmember. In accordance with other mineralized porphyry systems (i.e., Copper Cliff and Copper Flat deposits), most of the data follow the trend of ideal tschermak substitution occurring by the increasing of positive charges in the tetrahedral site of white mica owing to the increasing of Si substitution.
Economic Geology
Ali reza zarasvandi; Mohammad Ali Ali Abadi; Mohsen Rezaei; Houshang Pourkaseb
Abstract
The Mohammadabad deposit is located in vicinity of Delijan in central province and in terms of structural zones of Iran,in the Uremia dokhtar zone. Stratabound Fe-Ce mineralization in brecciated, vein, massive, layered and laminar forms, consists ore minerals such as hematite, pyrite, chalcopyrite and ...
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The Mohammadabad deposit is located in vicinity of Delijan in central province and in terms of structural zones of Iran,in the Uremia dokhtar zone. Stratabound Fe-Ce mineralization in brecciated, vein, massive, layered and laminar forms, consists ore minerals such as hematite, pyrite, chalcopyrite and magnetite ,is seen in lower Eocene volcano sedimentary unites. Amounts , ratios and diagrams of trace elements and rare earth elements show hydrothermal mineralization with the predominance of magmatic fluids. The values of δ34SCDT of sulfide minerals (-2.76 to1.51 ‰) and suggest the magmatic source for sulfur or mineralizing fluid with magmatic sulfur. The values of δ13C (mean 3.61 ‰), δ18O(mean12.946‰) related diagrams show a magmatic source for carbon, hydrothermal genesis for calcite and a mineralizing fluid dominantly magmatic source. above evidences,وthe location of the region in tensile tectonic regime in western edge position of uremia dokhtar magmatic arc during the Eocene and presence of magmatic mass in the depths of the region with high potential for iron and copper mineralization , sulfur supply ,also has played role of a heat engine to circulating and transfer of mineralizing fluids to the sea bed. Offers exhalative-hydrothermal processes model for deposit genesis in Eocene volcano sedimentary units
Sedimentology
hajar ghafleh maramazi; Fardin mousivand; alireza zarasvandi
Abstract
The Gol-e-Zard zinc-lead deposit is located in the Malayer-Isfahan belt of Sanandaj-Sirjan zone in northeast of Aligudarz, Lorestan province. Mineralization occurred as two different ore horizon within metamorphosed Jurassic shale and sandstone. Generally, two ore facieses were distinguished in the deposit: ...
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The Gol-e-Zard zinc-lead deposit is located in the Malayer-Isfahan belt of Sanandaj-Sirjan zone in northeast of Aligudarz, Lorestan province. Mineralization occurred as two different ore horizon within metamorphosed Jurassic shale and sandstone. Generally, two ore facieses were distinguished in the deposit: 1) vein-veinlet/stringer facies, and 2) bedded facies. Primary minerals of the ores involve pyrite, sphalerite, galena and chalcopyrite, and the secondary minerals include cerussite, smithsonite, azurite, malachite and goethite. The gangue minerals are quarts, chlorite, calcite and clay-mineral. In the stringer facies, chalcopyrite replaced mainly pyrite and other minerals indicating influx of a copper-rich hot fluid influx into a pyrite-rich ore called as “zone-refining process”. In the Gol-e-Zard deposit metal and mineralogical zonation was observed. Alteration zones have distinct pattern, silicic-carbonatic at core to chloritic at margins. Based on textures and structures, mineralogical, ore facies, alterations and geochemical characters, the zinc-lead mineralization in the Gol-e-Zard region is of Selwyn-type sedimentary-exhalative (SEDEX) deposits, deformed and metamorphosed by the Late Cimmerian and Laramid Orogenies at green schist facies.
Economic Geology
A. R. Zarasvandi; Fatemeh Davoodian Ranjbar; Mohsen Rezaei; M. Tashi; Houshang Pourkaseb
Abstract
Sarkuh porphyry copper deposit is located 180 km west of Kerman province, 6 km southwest of Sarcheshmeh porphyry copper mine in the northeast of Pariz city. Considering geological divisions, it is a part of Urumieh-Dokhtar magmatic arc. The exposed rocks in this area are mainly composed of volcanic units, ...
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Sarkuh porphyry copper deposit is located 180 km west of Kerman province, 6 km southwest of Sarcheshmeh porphyry copper mine in the northeast of Pariz city. Considering geological divisions, it is a part of Urumieh-Dokhtar magmatic arc. The exposed rocks in this area are mainly composed of volcanic units, tuffs, andesite and basaltic andesite. Also intrusive units include granite to granodiorite, and to a lesser extend quartz diorite rocks. Major alterations of the deposit include potassic, phyllic, argillic and propylitic, as well as intermediate alterations such as potassic - argillic and potassic - phyllic. The purpose of this research is to study the chemical features of biotite and chlorite in order to investigate the physicochemical attributes of porphyry system during magmatic to hydrothermal transition in the patassic alteration. Based on the temperatures of reequilibrated biotite, at the time of magmatic to hydrothermal transition, the temperature ranged from 343 to 397°C. Also high magnesium nature of biotites, and their plotting in the boundary of magnetite-hematite (HM) and nickel-nickel oxide (NNO) buffering lines, as well as presence of magnetite with hematite rims indicate previlling of the high oxygen fugacity during potassic alteration.
