Zircon documents the onset of Cretaceous magmatism on the Korean Peninsula

Research Summary

The Korean Peninsula has maintained a tectonic stability for approximately 1.5 billion years subsequent to igneous activity and metamorphism between 2.0 and 1.8 Ga. The peninsula underwent a resurgence of magmatic activity in the late Paleozoic, leading to the formation of Mesozoic-Cenozoic granitoids, which now encompass roughly one-third of the peninsula’s landmass. These granites predominantly originated from two distinct magmatic flare-ups. During the early to mid-Jurassic period, NE-SW trending large batholiths formed. After around 50 Ma magmatic hiatus, the Cretaceous flare-up began with the intrusion of granitoids in the Ganghwa, Pocheon, and Taebaek area. Chemical and isotopic features indicate that Early Cretaceous lithospheric thinning, most likely resulting from delamination of tectonically and magmatically overthickened lithospheric keel and consequent asthenospheric upwelling played vital roles in igniting the magmatic flare-up. This hypothesis is supported by zircon data obtained using SHRIMP and isotope microscope as well as laser ablation inductively coupled plasma mass spectrometer at the Korea Basic Science Institute.

Expected Outcomes

These findings are expected to serve as valuable foundational information for future investigations into volcanic hazards and the exploration of strategically significant mineral resources.

Related Figures

• [Figure 1] Electron microscope images of zircons from Cretaceous plutons
• [Figure 2] Schematic cartoon illustrating the Cretaceous tectonomagmatic evolution of the Korean Peninsula