Mineralogy, alteration, and sulfur isotope geochemistry of the Zehabad intermediate-sulfidation epithermal deposit, NW Iran
The Zehabad Pb-Zn-Au-Ag (Cu) deposit lies in the Alborz magmatic arc of northwestern Iran. Ore-bearing breccia veins hosted by Eocene tuffs emplaced along the 80–130° trending fault and fracture zone. Mineralization occurs in the contact of the late Eocene igneous bodies and the Eocene volcanic and...
| Autores: | , , |
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| Tipo de recurso: | artículo |
| Fecha de publicación: | 2019 |
| País: | España |
| Institución: | Universitat Politècnica de Catalunya (UPC) |
| Repositorio: | UPCommons. Portal del coneixement obert de la UPC |
| Idioma: | inglés |
| OAI Identifier: | oai:upcommons.upc.edu:2117/172731 |
| Acceso en línea: | https://hdl.handle.net/2117/172731 https://dx.doi.org/10.3906/yer-1902-1 |
| Access Level: | acceso abierto |
| Palabra clave: | Sulfur -- Isotopes Mineralogy -- Iran Alborz Epithermal Intermediate-sulfidation Iran Sulfur isotopes Zehabad Sofre -- Isòtops Mineralogia -- Iran Àrees temàtiques de la UPC::Enginyeria civil::Geologia::Mineralogia |
| Sumario: | The Zehabad Pb-Zn-Au-Ag (Cu) deposit lies in the Alborz magmatic arc of northwestern Iran. Ore-bearing breccia veins hosted by Eocene tuffs emplaced along the 80–130° trending fault and fracture zone. Mineralization occurs in the contact of the late Eocene igneous bodies and the Eocene volcanic and volcanosedimentary Karaj Formation. Mineralization formed in five stages: 1) disseminated framboidal pyrite and minor chalcopyrite and sphalerite; 2) quartz veins containing chalcopyrite, bornite, pyrite, and sphalerite; 3) deposition of specularite and gold grains hosted in quartz veins that crosscut chalcopyrite; 4) the main stage of mineralization that contains galena, sphalerite, tennantite-tetrahedrite, pyrite, sulfosalts, and gold; 5) barren quartz-calcite veins with sulfide mineral fragments of earlier stages. The hydrothermal alteration from closest to the veins outwards includes: a) silicification; b) phyllic with quartz, pyrite, sericite, and calcite; c) argillic with illite, kaolinite, and montmorillonite; d) propylitic containing epidote, calcite, chlorite, and sericite and; e) carbonatization that crosscuts all previous alteration types. Quartz and calcite are the most important gangue minerals at the deposit and show a close relationship with mineralization. Sulfur isotope compositions (0.8‰ to –10.1‰) suggest that the ore-forming fluids derived from magmatic sources with a temperature range of 276–288 °C. According to the field (macroscopic), microscopic, alteration, and sulfur isotope studies, the Zehabad base and precious metal mineralization is considered an intermediate-sulfidation epithermal deposit. |
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