Deciphering Magma Mingling Processes in the Zouzan Pluton, Eastern Iran: Multi‐Method Constraints from Zircon Geochronology, Nd‐Sr Isotopes and Amphibole‐Apatite Chemistry on Mafic Enclave Formation

ABSTRACT The Zouzan pluton in the Lut Block (eastern Iran) comprises coeval gabbro–diorite and felsic intrusions that contain abundant mafic enclaves (MEs). Integrated zircon U‐Pb dating, whole‐rock Sr‐Nd isotopes and amphibole‐apatite chemistry are used to investigate ME formation. Zircon ages indicate synchronous emplacement of the gabbro–diorite, MEs, and granodiorite ca. 40 Ma. The MEs plot along a Sr‐Nd isotopic mixing line between mantle‐derived gabbro–diorite and more crustally contaminated granodiorite, supporting a magma‐mixing origin. Mineral chemistry, however, reveals more complex interactions. Apatite in MEs is acicular with trace element compositions intermediate between those of mafic and felsic magmas, indicating rapid crystallisation from a hybrid melt. Amphiboles display two distinct compositional groups: one matching gabbro–diorite amphiboles and the other resembling those in the granodiorite. This bimodality suggests that ME formation involved incomplete mixing, crystal transfer between magmas and variable re‐equilibration rather than simple hybridisation. A dynamic model is proposed in which mafic magma globules were injected into a partly crystallised felsic chamber, producing mingling, quenching and crystal exchange that ultimately shaped the petrographic and geochemical features of the Zouzan pluton.