Linking Cu Mineralization to Host Porphyry Emplacement: Re-Os Ages of Molybdenites versus U-Pb Ages of Zircons and Sulfur Isotope Compositions of Pyrite and Chalcopyrite from the Iju and Sarkuh Porphyry Deposits in Southeast Iran
Abstract
The Kerman copper belt in Iran contains a number of important porphyry copper deposits, including Sarkuh and Iju. Molybdenite Re-Os isotope dating of the Sarkuh and Iju porphyry copper deposits shows that mineralization occurred at 15.14 ± 0.08 and 9.8 ± 0.06 Ma, respectively. Compared with the previous Re-Os dating of molybdenite in the region, it is revealed that Cu mineralization was an ongoing process in an arc setting during the Miocene. The available zircon dates of the granitic rocks from the Sarkuh (15.18 ± 0.43 Ma) and Iju (9.27 ± 0.50 Ma) porphyry copper deposits indicate that the mineralization occurred contemporaneously with the emplacement of collision-related ore-hosting porphyries. The Re content (1,715.40 ppm) of molybdenite and the δ^(34)S_(CDT) values (0.05‰) of pyrite-chalcopyrite from Iju are consistent with its origin of sulfur and metals from a dominantly mantle source. However, the lower Re content (302.21 ppm) of molybdenite and higher δ^(34)S_(CDT) values (3.20‰) of pyrite-chalcopyrite from Sarkuh suggest additional contributions from crustal materials. It is likely that the younger porphyry copper deposits in the Kerman copper belt, such as Iju, are related to the greater contribution of postcollisional mantle-derived magmas, while the older deposits (e.g., Sarkuh) were formed during the collisional event at the Oligocene-Miocene interval where the magma had some additions from the lower crustal melts generated during crustal thickening.
Additional Information
© 2013 Society of Economic Geologists, Inc. Submitted: April 10, 2012; Accepted: August 15, 2012. We thank the National Iranian Copper Industries Company (NICICO) for providing facilities for field trips to Sarkuh and Iju and permission to publish the data. We also thank Mark Baker and Joaquin Ruiz for assistance and use of the laboratory at the University of Arizona. Analytical assistance from Axel Schmitt and Rita Economos of the UCLA Keck ion microprobe facility is appreciated. We are grateful to Larry Meinert, David Selby, Michael Haschke, and an anonymous reviewer whose comments added greatly to this manuscript. H. Mirnejad acknowledges the University of Tehran for support during the course of this study.Additional details
- Eprint ID
- 39388
- DOI
- 10.2113/econgeo.108.4.861
- Resolver ID
- CaltechAUTHORS:20130716-101250706
- Created
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2013-08-12Created from EPrint's datestamp field
- Updated
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2021-11-09Created from EPrint's last_modified field