K-Ar ages of weakly metamorphosed rocks at the northern margin of Kurosegawa Terrane in central Shikoku and western Kii Peninsula: extent of the Kurosegawa Terrane in southwest Japan

Abstract

Weakly metamorphosed rocks of unknown origin distributed in the Chichibu Belt in central Shikoku and western Kii Peninsula, Southwest Japan, were studied by radiometric dating. The newly obtained ages are concentrated in a range between 229 and 186 Ma (Late Triassic to Early Jurassic), and they are compatible with those of the high-P/T metamorphic rocks in the Kurosegawa Terrane. -from English summary