Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Murakami, Hiroaki; Ashizawa, Masaomi*; Tanaka, Kazuhiro*
Oyo Chishitsu, 59(1), p.2 - 12, 2018/04
This study describes the features of fractures and their fillings along with the long-term behavior of their hydrogeological structures in an underground environment based on the results of a geological investigation conducted at an underground facility in northern Kyushu. Fractures were classified into five groups on the basis of fracture orientation: A, B, C, D, and low-angle groups. The genesis of all fractures is the cooling process of granodiorite pluton. Almost all of the water-conducting fractures are included in the B group. Because a number of fracture fillings in the B group are filled by prehnite and crushed fragments of epidote and quartz, the fractures in this group alternated sealing and re-opening. The fracture characteristics in the B group are follow as: accompanying many alteration halos, long trace length, and cutting off other fractures. These results indicate that fractures in the B group have possibly functioned as pathways for groundwater flow in the long term.
Nohara, Tsuyoshi; Sakai, Toshihiro; Murakami, Hiroaki
no journal, ,
Research on history of the fracture formation and fracture filling in the Toki granite was carried out, in the Mizunami Underground Research Laboratory (MIU) Project. It is recognized that some fractures in the Toki granite are related to high temperature fluid. Rock permeability was decreased by Quartz precipitations in the fracture which were related to injection of the high temperature fluid.