CHIME Ages of Precambrian Rocks from the Goseong-Ganseong Area, Northeastern Part of the Gyeonggi Massif, and Their Tectonic Implications

CHIME (chemical Th-U-total Pb isochron) geochronology were made for Precambrian rocks from Goseong-Ganseong area, northeastern part of the Gyeonggi massif. Zircon and/or monazite grains from orthogneisses give ages, and monazite grains from paragneisses yield similar ages ranging from suggesting that igneous intrusions and coeval metamorphisms were occurred over the area. Together with reported prevailing igneous activities and regional metamorphism from the Cyeonggi massif, our age data from Goseong-Ganseong area would be potentially correlated with long-lived global tectonotermal events in marginal outgrowth of supercontinent Columbia which was finally assembled by collisional orogenies at . Petrological and geochmical studies, however, should be followed to confirm this tectonic interpretation.