Abstract
The Takahama metamorphic suite, which belongs to the Nagasaki metamorphic sequence, is exposed in Amakusa-Shimoshima Island, western Kyushu, Japan. The Takahama metamorphic suite consists of two subhorizontal lithological units. The upper unit is separated from the lower by a thrust or shear zone and is composed of epidote amphibolites, garnet amphibolites, and garnet-mica gneisses. The lower unit is composed of pelitic schists, siliceous schists, and basic schists. The Upper Cretaceous Himenoura Group overlies the Takahama metamorphic suite with a subhorizontal fault contact. Therefore, the upper unit of the Takahama metamorphic suite is tectonically intercalated between the underlying lower unit and the overlying Himenoura Group. The Takahama metamorphic suite underwent at least six deformational events (D0-D5); the most conspicuous ductile deformation took place during D2. Kinematic indicators for D2 suggest northeastward extrusion of the upper unit. Integrating previous studies, these results support the interpretation that the Takahama metamorphic suite is a western extension of the Sanbagawa metamorphic belt.
