F. Mousivand; E. Rastad; M. H. Emami; J. M. Peter; M. Solomon
Abstract
Zn-Pb-Cu mineralization in the Chahgaz area, located 60 km south of Shahre Babak, occurs within a Middle Jurassic metamorphosed bimodal volcano-sedimentary sequence in the South Sanandaj-Sirjan zone. Mineralization occurs associated with exhalites within units 1and 2 of the host sequence as numerous ...
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Zn-Pb-Cu mineralization in the Chahgaz area, located 60 km south of Shahre Babak, occurs within a Middle Jurassic metamorphosed bimodal volcano-sedimentary sequence in the South Sanandaj-Sirjan zone. Mineralization occurs associated with exhalites within units 1and 2 of the host sequence as numerous occurrences, and within unit 3 as Chahgaz deposit and some occurrences hosted by meta-rhyolitic tuff, meta-rhyolite, and meta-pelites, as predominantly stratiform, tabular and sheeted-like orebodies at specific stratigraphic horizons. Ore textures include massive, semi-massive, banded, laminated, disseminated and vein-veinlets. Ore minerals are predominantly pyrite, sphalerite, galena, chalcopyrite, tetrahedrite, arsenopyrite, and minor bornite and pyrrhotite, and gangue minerals include dominantly sericite, quartz, chlorite and barite. Wallrock alteration is dominated by sericitic and chloritic and minor carbonatic and silicic types. Altered host rocks have been foliated due to metamorphism and deformation, and along with the associated ores have been folded and faulted and show cataclastic, triple junctions, pressure shadows, crenulations, and boudinage features. Based on geological, mineralogical, geochemical and alteration studies, it is inferred that Zn-Pb-Cu mineralization in the Chahgaz area has occurred as volcanogenic massive sulfide (VMS)-type in an arc rift basin, and has subsequently been metamorphosed under greenschist facies conditions during the Late Cimmerian and Laramid orogenies and younger events. This mineralization, in comparison with similar deposits in the world, has the most similarities with those deposits of siliciclastic felsic-type in the Bathurst Mining Camp, Canada, and Iberian Pyrite Belt in Spain and Portugal; and it is the first recognition of this type in Iran.
