Tectonic significance of the late Eocene (Bartonian) calc-alkaline granitoid body in the Marivan area, Zagros suture zone, northwest Iran

The Marivan granitoid body of the northern Sanandaj–Sirjan Zone (N-SaSZ) northwest Iran was emplaced into Cretaceous sediments, and is associated with minor amounts iron skarn-type mineralization along contact between intrusion surrounding country rocks. granitoids within include (hornblende-rich) diorite, granodiorite, granite phases, zircon U–Pb dating four samples from this indicate they were during late Eocene (Bartonian; 37.7 ± 1.0 Ma). These plutonic rocks can be classified two main types, granitic dioritic rocks, according to petrography whole-rock major element geochemistry. Both are high-K, some have an I-type affinity peraluminous metaluminous compositions. εNd(t) values that cluster around zero (–3.3 +3.0) low 87Sr/86Sr(i) (0.7040–0.7076), suggesting derivation a mafic juvenile crustal or depleted mantle source, which possibly calc-alkaline amphibolites lower crust. new ages petrological geochemical data presented in study suggest Palaeocene–early collision Arabian Iranian plates caused ascent emplacement hot magma through slab window This increased geothermal gradient root zone developing magmatic system at base continental crust, causing partial melting crust region. generated intermediate magmas either directly upper mixed varying material prior emplacement, formed diorite leucogranite range compositions intrusion.