Geology and mineralization at the copper-rich volcanogenic massive sulfide deposit in Nohkouhi, Posht-e-Badam block, Central Iran

Autor: Omid Asghari, Seyed Ahmad Meshkani, Mirsaleh Mirmohammadi, Saeid Hajsadeghi
Rok vydání: 2018
Předmět:
Zdroj: Ore Geology Reviews. 92:379-396
ISSN: 0169-1368
DOI: 10.1016/j.oregeorev.2017.11.030
Popis: The Nohkouhi copper deposit (1.5 Mt @ 1% Cu) is the first reported VMS deposit among several SEDEX deposits in Posht-e-Badam block, Central Iran. The deposit is primarily hosted by black shale and rhyodacite associated with Rizu Series. The Rizu Series is a volcano-sedimentary succession which was deposited in the Posht-e-Badam block during rifting of the continental margin of central Iran in the Late Precambrian to Early Cambrian. Pyrite and chalcopyrite are the dominant sulfide minerals, with subordinate galena and sphalerite. Sericite, calcite, barite, and quartz are the most abundant gangue minerals. Based on the dominance of sulfide minerals, two types of mineralization are distinguished: pyrite-rich ± chalcopyrite and chalcopyrite-pyrite rich. Considering mineralogy, the texture of sulfide mineralization, and crosscutting relationships, five ore textures are present: massive to semi-massive, laminated (banded or bedded), disseminated, brecciated, and veinlet-hosted. In the rhyodacite, sericite and carbonate are the main alteration minerals. Lithogeochemistry of felsic volcanic rocks are similar to FII rhyolite and are interpreted to have been resulted from partial melting of either continental or oceanic crust. Textural, mineralogical, and host rock alteration assemblages as well as geochemical characteristics of volcanic rocks of Nohkouhi deposit are in agreement with a copper-rich VMS deposit model.
Databáze: OpenAIRE
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