Sediment provenances and tectonic significance of the Daeheuksan Group, Southwestern Korean Peninsula

The Daeheuksan Group on Heuksando Island, southwestern Korean Peninsula, represents a small but tectonically significant sedimentary succession with a newly constrained Late Paleoproterozoic (Statherian) deposition. We integrated sedimentary petrography, whole-rock geochemistry, and detrital zircon U-Pb geochronology to unravel its sediment provenance and tectonic setting. The Munamsan, Mungnyeong, and Cheonchon formations collectively show quartzose to litho-quartzose compositions, influenced by sediment recycling, chemical weathering, and minor volcanic inputs. Despite lithological variations, consistent detrital zircon age spectra suggest stable sediment sources dominated by recycled Archean to Paleoproterozoic rocks. Whole-rock chemistry reveals intense chemical weathering and post-depositional potassium enrichment likely linked to alkaline magmatism. These findings collectively support deposition within an intracratonic extensional basin, coeval with regional post-collisional magmatic activity in the Korean Peninsula and eastern North China Craton. The Daeheuksan Group thus provides new evidence for Statherian extensional tectonism linked to the early breakup of the Columbia supercontinent, extending the record of Paleoproterozoic basin development in East Asia.