Geologic traverse of the Sambagawa metamorphic belt in central Shikoku, SW Japan:

Petrological and mineralogical contrasts of basic lithologies between eclogite and non–eclogite units along the Kokuryo River of the Sanbagawa belt, Central Shikoku, Japan

“…The Tonaru body belongs to the eclogite unit (Miyagi and Takasu, 2005), and thus, westward extension of the unit boundaries between the eclogite and non-eclogite units in the Besshi region should traverse the schist region on both the northern and southern sides of the Tonaru body or coincide with the lithologic boundaries between epidote-amphibolite and schist (Aoya et al, 2017). Garnet grains in the basic lithologies (basic layer, and amphibole-rich band and lens of the boundary zone) imply a critical contrast concerning their zoning patterns and compositional ranges.…”

“…The Kokuryo-gawa (Kokuryo River) route is situated along the western side of the Besshi region, and passes transversely across the boundary between the Tonaru epidote-amphibolite body, which underwent eclogite facies recrystallization (Miyagi and Takasu, 2005), and the sur-rounding pelitic and basic schists. Therefore, a possible westward extension of the boundary between the eclogite and non-eclogite units is expected to occur along this route (Aoya et al, 2017). In this study, we discuss the petrological and mineralogical similarities and differences of the lithologies at an outcrop including the probable boundary between these two units and define its exact position on the outcrop scale.…”