Tectonic evolution of the central Korean Peninsula: Insights into crustal architecture and geodynamic history

The central Korean Peninsula preserves a more than two-billion-year record of crustal growth, reworking, hybridization, and continental assembly along the eastern margin of the Eurasian Plate. Resolving the long-debated tectonic affinity of the Gyeonggi Massif and the Hongseong–Imjingang Belt is critical for reconstructing the crustal evolution of East Asia. Integrated zircon U Pb geochronology, Lu Hf isotopic data, whole-rock geochemistry, and regional geological correlations indicate that the Gyeonggi Massif and the Hongseong–Imjingang Belt form a dual-affinity hybrid crust that developed through long-term interactions between the North China Craton (NCC) and the South China Craton (SCC). Neoarchean to Paleoproterozoic TTG-type and arc–collisional suites establish an NCC-affinity basement, whereas subsequent Mesoproterozoic extension, Tonian arc magmatism, Cryogenian intraplate magmatism, and Paleozoic convergent-margin tectonomagmatism progressively overprinted this inherited basement with SCC-linked tectonomagmatic signatures, producing the present dual-affinity crust. Paleozoic calc-alkaline magmatism, back-arc basin development, and mixed detrital zircon provenance together reflect participation in convergent systems parallel to the northern Yangtze margin while recording variable SCC-derived contributions. Detrital zircon age spectra and εHf (t) values from Neoproterozoic to Paleozoic sedimentary successions document repeated mixing of Archean and Paleoproterozoic NCC-type crust, Tonian arc sources generated by juvenile mantle input and reworked older crust, and reworked Cryogenian to Paleozoic lithosphere. Triassic Songrim magmatism and high-pressure to ultrahigh-pressure metamorphism record continent–continent collision between the NCC and SCC. The spatially dispersed distribution of Triassic intrusions and metamorphic belts indicates that collision was accommodated across multiple structural belts rather than along a single suture. This integrated dataset supports a long-lived hybrid crustal model in which NCC-derived basement was progressively modified by SCC-linked Tonian arc magmatism, Cryogenian rift-related magmatism, and Paleozoic convergent-margin tectonomagmatism along the northern Yangtze margin, and was ultimately amalgamated during Triassic continent–continent collision.