[AGE40-P03] Fracture domain of granite based on orientation analysis and its relation to water conducting fractures: an example from the “-500m access/research gallery-North” of the Mizunami Underground Research Laboratory
Keywords:water conducting fracture, domain analysis, Granite
Domain analysis of granite on the basis of fracture orientation in the 100 m scale by means of structural geologic techniques such as stereographic projection, Strike Versus Traverse Distance (SVTD) diagram (Marshak and Mitra, 1988) and Sequential Linked Median (SLIME) plot (Fisher, 1993) revealed relationship between distribution of water conducting fractures and fracture orientations. This attempt used fracture data taken from the “-500m access/research gallery-North” of the Mizunami Underground Research Laboratory (Kawamoto et al., 2014a, b). Improvement of the SLIME plot based on running median of span 3 shows domain boundary (large kink of fracture trend) and kink in domains of fracture trend (small kink), and their relation to positions of water conducting fractures (Ishibashi et al., 2016, Hayashida et al., 2018, JAEA, 2020), more clearly. Water conducting fractures are concentrated at these kinks of fracture trend. A location of one of the large kinks corresponds to a region of fractures with geochemically high connectivity from deeper parts. Methods to make SLIME plot would also be shown in our presentation.
References:Fisher, N. I., 1993, Statistical analysis of circular data. Cambridge, 277p. Hayashida, et al., 2018, Chikyukagaku (Geochemistry), 52, 55-71.* Ishibashi, et al., 2016, Engineering Geology, 208, 114-127. Kawamoto, et al., 2014a, JAEA-Research, 2014-021, 30p.* Kawamoto, et al., 2014b, JAEA-Data/Code, 2014-014, 27p.* Marshak, S. and Mitra, G., 1988, Basic methods of structural geology. Prentice Hall, 446p. Sugimura, et al., 1997, Journal of Japan Society of Civil Engineers, 582, 229-246.* [URL] JAEA, 2020, https://www.meti.go.jp/shingikai/energy_environment/chiso_shobun/pdf/005_03_03.pdf ** *(in Japanese with English abstract), **(in Japanese).