Zircon U Pb Hf and geochemical analyses of paragneiss and granitic gneiss from Oki-Dogo Island, Southwest Japan and its tectonic implications

Abstract The paragneiss and migmatitic gneiss on Oki-Dogo Island, located in northern part of southwest Japan, have U Pb ages ranging from Mesoarchean to Paleoproterozoic. The youngest population of detrital zircons from the paragneiss and migmatitic gneiss suggests a maximum depositional age of ca. 1.96 Ga. Further, the three granitic gneiss samples give zircon U Pb ages of 1.97, 1.88, and 1.81 Ga. The bulk rock composition of the granitic gneiss samples followed a calc-alkaline trend and showed negative Nb, Ta, P, and Ti anomalies with low Sr/Y (