Magmatic origin and geochemical evolution of the intrusions in the Dahane-ye Gomrokan porphyry copper deposit, Urumieh–Dokhtar magmatic arc, Iran: Evidence for calc-alkaline to adakitic magmatism

Articles in Press

Document Type : Original Article

Authors

1 Department of Economic Geology, Tarbiat Modares University, Tehran, Iran

2 Department of Economic Geology, Tarbiat Modares University, Tehran, Iran,

3 Department of Earth Sciences, Faculty of Natural Science, University of Tabriz, Tabriz, Iran

Abstract

The Dahane-ye Gomrokan porphyry copper deposit, located ~70 km northeast of Jiroft, occurs in the southeastern segment of the Urumieh–Dokhtar magmatic arc within the Jebal-Barez sub-zone and represents a typical magmatic–hydrothermal system associated with calc-alkaline to adakitic magmatism in a convergent tectonic setting. This study investigates the petrographic characteristics, magma sources, and evolutionary history of the intrusive rocks using field observations, petrography, and whole-rock geochemistry of major, trace, and rare earth elements. The intrusions comprise granodiorite, tonalite, and quartz monzonite–quartz monzodiorite with subalkaline affinity. Granodiorites and quartz monzonites belong to the high-K calc-alkaline series, whereas tonalites are metaluminous and classified as I-type granitoids. Enrichment in large-ion lithophile elements (LILE) and light rare earth elements (LREE), together with depletion in high-field-strength elements (HFSE), including Nb, Ta, and Ti, indicates magma generation in a subduction-related magmatic arc. Elevated Sr/Y and La/Yb ratios and depleted HREE patterns imply residual garnet in the source and partial melting at high pressure. Geochemical modeling suggests that tonalites were generated by partial melting of eclogitic to garnet-amphibolitic sources, quartz monzonites from amphibolitic sources, and granodiorites from typical calc-alkaline parental magmas. Collectively, the magmatic evolution of the Dahane-ye Gomrokan system resulted from the combined effects of subduction, slab rollback, and slab break-off, which promoted the generation of fertile adakitic magmas and ultimately favored porphyry copper mineralization.

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Petrological Journal

Articles in Press, Accepted Manuscript
Available Online from 14 September 2026

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History

  • Receive Date: 11 July 2026
  • Revise Date: 07 September 2026
  • Accept Date: 14 September 2026

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