The Guodian Fe deposit is representative of the newly discovered Qihe–Yucheng high-grade Fe skarn ore cluster, Luxi Block, eastern North China Craton (NCC). The age of the Pandian Fe deposit remains elusive, which hinders the understanding of its metallogenic tectonic background. Phlogopites are recognized in syn-ore stages, and they are closely associated with magnetite in the Guodian skarn Fe deposit. Here, we carried out ⁴⁰Ar/³⁹Ar dating of phlogopite, which can place a tight constraint on the timing of Guodian iron mineralization and shed light on the geodynamic framework under which the Guodian Fe deposit formed. Ore-related phlogopite ⁴⁰Ar/³⁹Ar dating yielded ⁴⁰Ar/³⁹Ar plateau ages of 131.6 ± 1.7 Ma at 890–1400 °C, with the corresponding isochron age being 131.1 ± 2.6 Ma. These two ages are consistent within the error, indicating that they can represent the formation age of the Guodian iron deposit. The mineralization age overlaps the zircon U-Pb age of 124.4 Ma for ore-related Pandian pluton. This age consistency confirms that the iron skarn mineralization is temporally and likely genetically related to Pandian diorite. The present results, coupled with existing isotopic age data, indicate the Guodian skarn Fe deposit formed contemporaneously with large-scale skarn iron mineralization over the Luxi Block in the Late Mesozoic. The available data demonstrated that the eastern NCC was “destructed” in the Late Mesozoic, as marked by voluminous igneous rocks, faulted-basin formation, high crustal heat flow, and widespread metamorphic core complexes in the eastern part of the NCC. It is thus suggested that the Guodian Fe skarn deposits, together with other deposits of similar ages in the Luxi Block and even in the eastern NCC, were products of this craton destruction. Lithospheric extension and extensive magmatism related to the craton destruction may have provided sufficient heat energy, fluid, chlorine, and Fe for the formation of the Fe deposit.

Orogenic gold deposits represent the most important gold resource globally after Witwatersrand-style conglomerate-hosted gold systems and have remained a major focus of economic geological research and mineral exploration over the past few decades. This review systematically summarizes the spatiotemporal distribution, geological characteristics, tectonic controls, ore-forming material sources, and genetic models of orogenic gold deposits. Orogenic gold mineralization is closely genetically related to the assembly and evolution of global supercontinents, exhibiting three prominent episodic mineralization periods at 2.8–2.55 Ga, 2.1–1.8 Ga, and 600–50 Ma. These deposits are widely developed in Precambrian cratons and Phanerozoic orogenic belts and display strong diversity in host-rock lithologies, including greenstone belts, turbidite sequences, carbonate strata, and intermediate-felsic intrusions. Corresponding mineralization styles, wall-rock alteration assemblages, and trace element zoning vary systematically with formation depth, temperature, and pressure, forming a classic epizonal–mesozonal–hypozonal crustal-continuum metallogenic framework. Compressional settings dominate traditional orogenic mineralization, with ore formation controlled by ductile–brittle shear transition, crack–seal cycles, and fluid-stress coupling at different crustal levels. Increasing evidence suggests the gold deposits may also form in post-orogenic settings under extensional conditions, where tectonic activities can reactivate pre-existing orogenic structures and facilitate fluid migration and superimposed mineralization, although this category remains debated and represents an expanded interpretation of orogenic gold systems. In terms of ore genesis, three prevailing models, namely the crustal metamorphic devolatilization model, the basin-scale two-stage carbonaceous sediment-source model, and the deep-seated metamorphic metallogenic model, have been proposed. Meanwhile, increasing evidence also indicates that magmatic–hydrothermal fluids provide indispensable material and fluid contributions to some orogenic gold systems, although metamorphic fluids remain the widely invoked fluid source for most orogenic gold deposits. This contribution provides a comprehensive theoretical review for further genetic research of global orogenic gold deposits.

The Khanbogd-Erdene region in southern Mongolia is a globally important copper–polymetallic metallogenic province, hosting large to super-large deposits, such as Oyu Tolgoi and Tsagaan Suvarga. The area experiences frequent tectonic–magmatic activity, particularly Late Paleozoic subduction-related magmatism, which controls the occurrence of large-scale copper–polymetallic mineralization. This study focuses on the Late Paleozoic granitic intrusive rocks in the Khanbogd-Erdene region of southern Mongolia. Using LA-ICP-MS and SHRIMP dating techniques, precise zircon U–Pb ages were obtained for 10 samples. A total of 209 zircon grains from these 10 intrusive rocks were analyzed, with most cathodoluminescence (CL) images of zircon grains showing distinct oscillatory zoning. Th/U ratios ranging from 0.11 to 2.92 indicate they are magmatic. The younger group of granitic rocks yielded ages between 260.2 ± 1.2 Ma and 286.6 ± 0.9 Ma, indicating an Early Permian geological age. The other seven samples yielded older ages between 315.9 ± 1.8 Ma and 340.9 ± 0.9 Ma, indicating a Carboniferous geological age. These large-scale Carboniferous to Early Permian intrusive rocks in the Khanbogd-Erdene region are products of tectonic–magmatic activity during specific stages of crustal evolution. The findings provide reliable chronological data for regional tectonic–magmatic activity and offer new evidence for constraining the timing of the Variscan orogeny in southern Mongolia.