Constraints of intrusive rocks on gold mineralization in Liziyuan Gold Deposit, West Qinling Orogenic Belt: Insights from petrogeochemical characteristics, zircon U−Pb ages, and zircon trace elements

To accurately constrain the emplacement age of intrusive rocks in the Liziyuan Gold Deposit, West Qinling Orogenic Belt, elucidate their petrogenesis and tectonic setting, and clarify their constraints on the regional gold mineralization timing, whole-rock analysis, zircon U−Pb dating, and trace element analysis were carried out on monzogranite and syenite. Combined with various zircon trace element discrimination diagrams, the rock types, source characteristics, and tectonic settings were systematically identified. The dating results show that the emplacement ages of monzogranite and syenite are 217.2 Ma ± 2.6 Ma and 210.4 Ma ± 2.3 Ma, respectively, indicating they were formed during the early Indosinian magmatic event. Zircon trace element characteristics reveal that the monzogranite and syenite exhibit typical I-type granite affinity and were mainly derived from continental crustal materials. Zircons display positive Ce anomalies and negative Eu anomalies, suggesting that the magma formed under relatively high oxygen fugacity and possibly underwent plagioclase fractionation. Tectonic discrimination indicates that the monzogranite and syenite were emplaced during the transition from anorogenic to orogenic settings, accompanied by crustal thickening. Comprehensive analysis demonstrates that the monzogranite and syenite were formed during the Late Triassic Indosinian and were generated by partial melting of continental crust materials under a collisional orogenic setting. Integrated with previously published zircon ages for magmatism and mineralization, a complete metallogenic temporal sequence of "pluton emplacement （210–214 Ma） →hydrothermal mineralization （207 Ma）" is established, and a dual-constraint model of "pluton age + mineralization age" is proposed. This study provides key geochronological and geochemical evidence for further understanding the magma-mineralization evolution in the West Qinling Orogenic Belt.