Abstract
The Omogiyama hornfels is one of the hornfelses sporadically occurring in the Sanbagawa metamorphic belt, central and western Shikoku, southwest Japan. They are originated from the Sanbagawa basic schists and distributed parallel to its schistosity. Large igneous bodies have not been found around the hornfels. The hornfelses are characterized by the assemblage of hornblende + actinolite + biotite + plagioclase + quartz. Based on the lack of large igneous rocks and the mode of occurrence of the Omogiyama hornfels, it seems that the hornfels was formed by high-temperature fluid flow along the schistosity of the Sanbagawa basic schists.
