Rb-Sr study of granite and gneiss from Seoul, South Korea
Granite from Seoul, Korea, has Rb-Sr whole-rock ages of 161 ± 1 m.y. and an initial Sr 87 /Sr 86 ratio of 0.7116 ± 0.0003. Thermal effects associated with the intrusion of granite lowered the Rb-Sr ages of middle Precambrian gneiss.