Petrogenesis, tectonic setting and metallogenic potential of the Late Paleozoic and Late Mesozoic granitoids in the Central Great Xing'an Range, NE China

Abstract

Granitoids are widely distributed throughout the Central Great Xing'an Range (CGXR). Determining their emplacement timing and stages is essential for reconstructing the tectonic and magmatic evolution of northeastern China. This study integrates geochemical, isotopic, and geochronological analyses of the Jalaid Banner-Zhalantun pluton to constrain its magma sources, petrogenesis, and tectonic setting, while investigating the link between magmatism and Cu-Mo-Au mineralization. Geochronological data indicate that the CGXR are predominantly composed of Late Carboniferous–Early Permian and Early Cretaceous (early and late stage) granitoids. Geochemical analyses reveal that the Late Carboniferous–Early Permian granites are highly to moderately fractionated I-type, characteristic of typical continental arc magmatic rocks. The early Early Cretaceous granites are classified as adakites, resulting from partial melting of newly thickened lower crust, whereas the late Early Cretaceous granite porphyry is classified as A1-type granite, with its primary magma likely derived from partial melting of juvenile crustal rocks under low-pressure conditions. Integrating the geochronological, geochemical, and Hf isotope data of Late Paleozoic and Late Mesozoic granitoids, we propose that the collision orogenic time between Xing'an block and Songliao block in the CGXR is not later than the Late Carboniferous–Early Permian. Since the earliest Cretaceous, the Paleo-Pacific Ocean regime became the predominant geodynamic control in NE China, with the superposition of Mongolia-Okhotsk Ocean regime also playing a role during the early Early Cretaceous. Additionally, the positive correlation between zircon Ce⁴⁺/Ce³⁺ value, magmatic oxygen fugacity and porphyry Cu-Mo ore scale suggests that the early Early Cretaceous granodiorite porphyry has significant metallogenic potential.