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Niwa, Masakazu; Shimizu, Mayuko; Yasue, Kenichi; Nishimura, Shusaku; Amamiya, Hiroki; Ueki, Tadamasa; Horiuchi, Yasuharu
no journal, ,
Uplift and associated denudation of mountains affect hydraulic gradient and groundwater flow path. In the case of a safety assessment for geological disposal of radioactive wastes, uplift and denudation will be examined in terms of nuclide migration driven by deep groundwater as well as potential exposure of repositories. Provenance analysis based on sedimentological, petrological, mineralogical and geochemical approaches in downstream area is often helpful for understanding onset times and processes of uplift and associated denudation of mountains in upstream area. In this study, quick quantification analysis for heavy minerals and measurement of electron spin resonance signal for quartz to estimate provenance rocks, and paleo-current analysis using magnetic anisotropy of susceptibility for fine sand were developed.
Ishimaru, Tsuneari; Yasue, Kenichi*; Onoe, Hironori; Matsuoka, Toshiyuki; Komatsu, Tetsuya; Iwatsuki, Teruki; Takeuchi, Ryuji; Kato, Tomoko; Sasao, Eiji
no journal, ,
JAEA have been developing the Geological-Evolutionary Models (GEMs) taking into account of long-term change of the geological environment in order to evaluate the geosphere stability. The purpose of the GEMs is to establish modeling techniques, which can express a long-term change of the geological environments. In addition, this project has the R&D such as the methodology for verification and an uncertainty estimate of the models, and the visualization technology of the model. In this R&D, FEP (Features, Events and Processes) analysis and scenario development for geological-evolutionary modeling of mountain area and plain area have been carried out. Paleo-hydrogeological model were constructed in consideration for long-term geological environments such as topography, geology and surficial environment, and spatial distribution of long-term stability of groundwater flow.
Ishibashi, Masayuki; Morikawa, Keita*; Sasao, Eiji; Yuguchi, Takashi*
no journal, ,
no abstracts in English
Nohara, Tsuyoshi; Tsuchiya, Noriyoshi*
no journal, ,
A trace of a high-temperature fluid in the Toki granite is investigated using pre-existing boring core of MIU. Fractures filled with secondary formed biotite and pores filled with quarts are recognized. It is considered that these filling minerals are traces of a high-temperature fluid in the past.
Ishii, Eiichi
no journal, ,
no abstracts in English
Ueki, Tadamasa; Shimizu, Mayuko; Sano, Naomi; Niwa, Masakazu
no journal, ,
no abstracts in English
Shimizu, Mayuko; Sano, Naomi; Ueki, Tadamasa; Yonaga, Yusuke; Niwa, Masakazu
no journal, ,
no abstracts in English
Terusawa, Shuji; Shimada, Koji
no journal, ,
The direction of the crack in the granite may have directionality, and it appears as a topography such as a linear valley. Attempts have been made to estimate stress field from the predominant direction. We compiled the results of geological survey which was conducted near the Monju cite in 2007 to 2015, and extract the predominant direction of cracks. As a result, in the northeastern area of the survey area, the north northeast and the west northwest direction were predominant, in the southwest, the northeast and the northwest direction were predominant. The included angle was about 60 to 80 degrees in the northeastern area and about 90 degrees in the southwestern area, and the dip angle was 60 to 80 degrees in both areas. The differences in the predominant direction in the northeastern part and the southwest part may proved by surveys which focusing on the presence or absence of minute displacement of individual joints, more extensive survey.
Shimada, Koji; Terusawa, Shuji
no journal, ,
Representativeness of the crush zone for activity evaluation at the Monju site was investigated by means of statistics of length distributions. The length distribution was exponential indicating a coalessence stage of the crush zone development. Thus the choice of the crush zone to be evaluated during our preceded research (2012-2016) was reasonable. We also payed attention for the future systematic and practical survey from the view point of superposed deformation. That is, in our experience, a superposed deformation observed at the weakest portion in the crush zone system, suggesting that the research on the longest crush zone with an attention at the weakest zone preferable for superposed deformation seems to be a practical research procedure.
Iwamori, Akiyuki*; Takagi, Hideo*; Shimada, Koji; Asahi, Nobutaka*; Sugimori, Tatsuji*; Sasaki, Toshinori*; Aiyama, Kotaro*
no journal, ,
no abstracts in English
Hatano, Nozomi*; Yoshida, Koki*; Irie, Shiori*; Mori, Saori*; Natori, Wakako*; Adachi, Yoshiko*; Sasao, Eiji
no journal, ,
Understanding of climate change is one of important issue to consider future climate change. In this study paleoweathering condition of middle Miocene and Pliocene periods is examined based on paleosol facies, chemical weathering degree and clay mineral composition of Miocene to Pliocene sediments distributed in central to southwestern part of Japan.