@article{oai:nagoya.repo.nii.ac.jp:00001440, author = {Dunkley, Daniel J. and Suzuki, Kazuhiro}, journal = {The Journal of earth and planetary sciences, Nagoya University}, month = {}, note = {The chemical Th-U-total Pb isochron method (CHIME) was used to obtained in-situ age estimates of monazite in metapelitic granulite gneiss from the Higo metamorphic terrane of western central Kyushu, west Japan. The terrane comprises metasedimentary and igneous lithologies that underwent high-grade metamorphism during a tectonic event considered by previous authors to have occurred in either the mid Cretaceous or the Permian-Triassic period. Monazite grains in the analysed sample occur in textural equilibrium with the peak metamorphic assemblage spinel-sillimanite-garnet-plagioclase-biotite, and are oriented parallel to a strong mineral foliation and gneissosity that was developed during peak metamorphism. This monazite yielded a CHIME age of 108±12Ma. Garnet grains also contain monazite grains as inclusions, which yield similar CHIME ages to the oriented monazite. On the basis of such petrographic evidence, the age estimates are interpreted as representing the time of peak metamorphism and deformation. This estimate is contrary to studies which suggest that the gneisses formed during the Permian-Triassic and that Cretaceous age estimates reflect isotopic resetting during the intrusion of an adjacent granitoid., 国立情報学研究所で電子化したコンテンツを使用している。}, pages = {1--14}, title = {Petrographically constrained CHIME dating of monazite from the Higo metamorphic terrane, Kyushu, Japan : preliminary results from metapelitic gneiss}, volume = {48}, year = {2001} }