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The Shahrak intrusive body (SIB) occurs at the intersection of the Urumieh-Dokhtar Volcanic Belt and the Sanandaj-Sirjan metamorphic belt in northwest Iran. This intrusive body consists of granodiorite, monzonite, monzodiorite, and monzogabbro, that intruded Oligo-Miocene sedimentary units and Cretaceous and Precambrian metamorphic rocks. Iron mineralization has occurred as magnetite skarn with hematite and pyrite in calcareous units at the contact with the SIB. The Rb-Sr age dating shows that the age of the SIB is about 24.9 Ma (Chattian). Whole rock geochemical studies indicate that the magma has calc-alkaline to high-K calc-alkaline affinities and is metaluminous. The multi-elements spider diagrams normalized to chondrite and primitive mantle show significant enrichment of light rare earth element against heavy rare earth element and depletion of Ti, P, Ta, and Nb, indicating characteristic features of the volcanic arc rocks in a subduction setting. Furthermore, the various types of tectonomagmatic diagrams show that these rocks are generated in an active continental margin. The parental magma of the rocks probably originated from an enriched mantle on the basis of the geochemistry of the REE elements. The average Sr isotopic composition of the SIB is 87 Sr/ 86 Sr(i) = 0.706. Therefore, the parent magma of the SIB may be the result of partial melting of enriched mantle or subducted slab contaminated with the continental crust. The sulfur isotope composition of pyrite grains (ave., +5.29 ‰) in the Korkora-1 iron deposit indicates that the sulfides are formed from magma or due to in situ dissolution and leaching of igneous sources. Dehydration melting of the subducted part of oceanic crust has likely produced the fluids that are necessary for melting of the mantle wedge to produce mafic-intermediate melts. The generated melts penetrated into the crust, and during their ascent they underwent a little crustal contamination and eventually were emplaced as intrusive bodies comprising gabbrodiorite to granodiorite.

Late Miocene volcanic rocks host the Sari Gunay epithermal gold deposit in NW Iran. These rocks are located within the Hamedan–Tabriz volcanic belt and occupy the northwestern part of the Sanandaj–Sirjan zone (SaSZ). The volcanic rocks span in composition from latite to dacite and rhyolite. Plagioclase, hornblende, biotite and quartz are the main phenocrysts in a fine-grained and glassy matrix. Laser ablation inductively coupled plasma mass spectrometry zircon U–Pb dating yielded crystallization ages of 10.10 ± 0.01 Ma and 11.18 ± 0.14 Ma for rhyolite and dacite, respectively. High ratios of Sr/Y (> 20) and La/Yb (> 20), high contents of Sr (≥ 400 ppm), low contents of MgO (≤ 6 wt%), Y ≤ 18 ppm (c. 16.5 ppm), Yb ≤ 1.9 ppm (c. 1.53 ppm) and weak negative Eu anomalies (Eu*/Eu c. 0.81) are compatible with a high-silica adakitic signature of the rocks. Regarding the location of the study area nearly 100 km from the Zagros suture zone, we argue that delamination of lithospheric mantle beneath the SaSZ has played a key role in the development of the adakitic rocks in a post-collision tectonic regime. The adakitic melts are suggested to have formed by partial melting of delaminated continental lithosphere and/or lower crustal amphibolite following the collision of the Arabian and Iranian plates.