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The Sungun porphyry ore deposit is located in Eastern Azarbaijan province, Northwestern Iran. The oldest intrusive pulse in the region is a quartz-monzonite pluton, which hosts the porphyry copper-molybdenum mineralization. The Sungun Copper Mine includes the mineralized Sungun porphyry as well as six groups of cross-cutting and lithologically distinct post-mineralization dykes. The composition of these dykes ranges from quartz diorite, gabbro, diorite, dacite, lamprophyre, and microdiorite. Quartz diorite and dacite dykes are the oldest and youngest dykes, respectively. Based on their cross-cutting relationships, the composition of the dykes tend to become more primitive through time. The dykes strike Northwest–Southeast with Southwest dip, sub-parallel to the reverse faults within the deposit area. The lamprophyric dykes range from phonotephrite, to trachybasalt, tephrite, and basanite. The quartz-monzonite porphyry (SP) and the post-mineralization dykes (DK1-DK3) have clear and distinct negative anomalies of Ti, Zr, P, Pr, Ce, and Nb, as well as positive anomalies of Cs, U, K, Pb, and Nd with respect to primitive mantle. Microdioritic dykes (MDI) show depletion of Ti, Nb, P, Ta, Th, Yb, and Zr, and enrichment of Cs, Ba, U, Pb, Nd. The similarities in trace element abundances and patterns in the porphyry and post-mineralization calc-alkaline dykes implies a single source and fractional crystallization as the main mechanism controlling magmatic evolution in a collisional environment. Lamprophyric dykes have enrichment of LREE and LILE and depletion of HREE and HFSE such as Ti, Nb, and Ta. The parent magma of the lamprophyric dykes (LAM) was likely derived by low degrees of melting of a garnet lherzolite mantle peridotite. The 87Sr/86Sr and 143Nd/144Nd ratios range from 0.704617 to 0.706464 and from 0.512648 to 0.512773 for the dykes suggesting that the parental magmas came from a progressively more enriched mantle. Isotope ratios of 87Sr/86Sr and 143Nd/144Nd support a cogenetic relationship of porphyry and calc-alkaline dykes, except for the microdiorite ones. A common primary melt underwent gravity differentiation in a deep magmatic chamber to form a dioritic magma. This subsequently migrated to shallower levels to evolve further and feed individual dyke groups into the Sungun porphyry.

Gabbro and diorite xenoliths occur within the alkaline trachyandesites in the northern part of Uromieh-Dokhtar magmatic belt (NW Iran). The host volcanic rocks are located on the upper Miocene sediments; therefore, they are probably Plio-Quaternary in age. The texture of xenoliths is granular, and the gabbro xenoliths are classified into two groups based on their petrographic characteristics and mineral chemistry. Based on chemical analyses, xenoliths show a subalkaline to slightly alkaline magmatic trend. Thermobarometric results indicate that gabbro and diorite xenoliths formed within the middle crustal level. All xenolith samples are light rare earth elements (LREEs) enriched and depleted in Ta, Zr, and Nb. These features can be explained by the subduction of the Neotethys. The LREE enrichment as well as negative Th, Ti, Nb, and Zr anomalies and positive Pb anomaly are in agreement with an origin through partial melting of an enriched mantle previously affected by metasomatism processes linked to mantle wedge-derived melts (fluids). Different REE concentration levels and patterns for Group 1 gabbro, Group 2 gabbro, and diorite xenoliths point out that their parental melts were not the same. Those forming the Group 1 gabbro xenoliths originated from melting of garnet mantle lherzolite, whereas the parental melts from Group 2 gabbro and diorite xenoliths originated from melting of spinel-garnet mantle lherzolite. The 86 Sr/ 87 Sr and 143 Nd/ 144 Nd ratios and chemical composition of minerals are different for host volcanic rocks and xenoliths; therefore, we may conclude that the parental melts of the different groups of xenoliths and host volcanic rocks differ in composition.

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The Sungun copper–molybdenum porphyry deposit is located in the north of Varzaghan, northwestern Iran. The Sungun quartz-monzonite is the oldest mineralized intrusive body in the region and was emplaced during the Early Miocene. Eight categories of the late and unmineralized dykes, which include quartz diorite, gabbrodiorite, diorite, dacite, microdiorite and lamprophyre (LAM), intrude the ore deposit. The main mineral phases in the dykes include plagioclase, amphibole and biotite, with minor quartz and apatite and secondary chlorite, epidote, muscovite and sericite. The composition of plagioclase in the quartz diorite dykes (DK1a, DK1b and DK1c) varies from albite-oligoclase to andesine and oligoclase to andesine; in the diorite, it varies from andesine to labradorite; in the LAM, from albite to oligoclase; and in the microdiorite (MDI), it occurs as albite. Amphibole compositions are consistent with classification as hornblende or calcic amphibole. Based on their AlIV value (less than 1.5), amphibole compositions are consistent with an active continental margin affinity. The average percentage of pistacite (Ps) in epidotes formed from alteration of plagioclase and ferromagnesian minerals is 27–23% and 25–30%, respectively. Thermobarometric studies based on amphibole and biotite indicate approximate dyke crystallization temperature of 850–750℃, pressure of 231–336 MPa and high fO2 (>nickel-nickel-oxide buffer). The range of mineral compositions in the postmineralization dyke suite is consistent with a genetic relationship with the subduction of the Neotethys oceanic crust beneath the continental crust of the northwest part of the Central Iranian Structural Zone. Despite the change from calc-alkaline to alkaline magmatism, the dykes are likely related to the late stages of magmatic activity in the subduction system that also generated the porphyry deposit.