Study on geology on the Mizunami Underground Research Laboratory Project; Geology and geological structure from the surface to G.L. -300m

Kuboshima, Koji; Ishibashi, Masayuki; Sasao, Eiji   ; Tsuruta, Tadahiko  ; Tagami, Masahiko*; Yuguchi, Takashi

The MIU (Mizunami Underground Research Laboratory) Project has three overlapping phases, Surface-based investigation phase (Phase I), Construction phase (Phase II), and Operation phase (Phase III). Currently, the project is under Phase II and Phase III. One of Phase II goals is set up to develop and revise models of the geological environment using the investigation results obtained during excavation, and to determine and assess changes in the geological environment in response to excavation. This report aims compiling results of study on geology and geological structure from the surface to G.L. -300m in the Phase II and provides the fundamental information on the geology and geological structure for future study. The compiling results of this report reflected basic data are utilized in the updating of the geological models in the Phase II.