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Yamasaki, Seiko*; Zwingmann, H.*; Yamada, Kunimi*; Tagami, Takahiro*; Umeda, Koji
Chemical Geology, 351, p.168 - 174, 2013/08
Times Cited Count：23 Percentile：58.57(Geochemistry & Geophysics)Constraining of the timing of fault zone formation is of fundamental geotectonic importance to understand structural evolution and brittle fault processes. Here, we present authigenic illite K-Ar age data from brittle fault zones comprising two gouges within the Toki granite, central Japan. The gouge samples were collected from a shaft at the Mizunami Underground Research Laboratory, and were separated into five grain-size fractions. K-Ar ages of clay fractions decrease with grain size, suggesting enrichment in finer fraction of more-recently grown authigenic illites. The K-Ar ages of the fractions range from 53.6 to 42.7 Ma (Paleogene-Early to Middle Eocene). The 
0.1 
m fractions yield ages of 42.7 and 46.5 Ma. This age range is consistent with the stability field of illite and the main temperature field of brittle deformation within the cooling history of the Toki granite, supported by extensive thermochronological data of the host rock.
Asamori, Koichi; Niwa, Masakazu; Hanamuro, Takahiro; Yamada, Kunimi; Kusano, Tomohiro; Makuuchi, Ayumu; Takatori, Ryoichi; Kokubu, Yoko; Matsubara, Akihiro; Ishimaru, Tsuneari; et al.
JAEA-Research 2012-024, 132 Pages, 2012/09
JAEA-Research-2012-024.pdf:15.68MB
This annual report documents the progress of R&D in the 2nd fiscal year during the JAEA 2nd Midterm Plan (FY 2010 - 2014) to provide the scientific base for assessing geosphere stability for long-term isolation of the high-level radioactive waste. The planed framework is structured into the following categories: (1) development and systematization of investigation techniques for selecting suitable sites in geosphere stability, (2) development, application and verification of prediction models for evaluating the changes of geological environment in thermal, hydraulic, mechanical and geochemical conditions for a long period of time, and (3) development of new dating techniques for providing information about geologic history and the timing of geologic events. In this paper, the current status of R&D activities with previous scientific and technological progress is summarized.
Asamori, Koichi; Niwa, Masakazu; Hanamuro, Takahiro; Yamada, Kunimi; Kusano, Tomohiro; Makuuchi, Ayumu; Takatori, Ryoichi; Kokubu, Yoko; Ishimaru, Tsuneari; Umeda, Koji
JAEA-Review 2012-024, 44 Pages, 2012/07
JAEA-Review-2012-024.pdf:1.29MB
The concept of geological disposal of HLW in Japan is based on a multi-barrier system which combines a stable geological environment with a robust barrier system. Potential geological host formations and their surroundings are chosen, in particular, for their long-term stability, taking into account the fact that Japan is located in a tectonically active zone. This report is a plan of research and development (R&D) on geosphere stability for long-term isolation of HLW in JAEA, in fiscal year 2012. The objectives and contents in fiscal year 2012 are described in detail based on the outline of 5 years plan (fiscal years 2010-2014). In addition, the planed framework is structured into the following categories: (1) Development and systematization of investigation techniques, (2) Development of models for long-term estimation and effective assessment, (3) Development of dating techniques.
Yamada, Kunimi; Yasue, Kenichi; Iwano, Hideki*; Yamada, Ryuji*; Umeda, Koji; Omura, Kentaro*
Chishitsugaku Zasshi, 118(7), p.437 - 448, 2012/07
Fission-track analyses for samples corrected from around the Atera fault indicated 2 conclusions. The dip-slip displacement of the Atera fault after Cretaceous is about 1 km. It is similar to the displacement of basement rocks or topography across the fault. These are consistent with previous studies that indicated the present Atera fault activity began after late Pliocene. The fracture zone along the fault was widely heated at about 20 Ma. It indicates that the fracture zone existed at the time and perhaps the paleo fault activity has already begun.
Yamada, Kunimi; Hanamuro, Takahiro; Tagami, Takahiro*; Shimada, Koji; Takagi, Hideo*; Yamada, Ryuji*; Umeda, Koji
Journal of Asian Earth Sciences, 45(2), p.17 - 23, 2012/02
Times Cited Count：3 Percentile：8.68(Geosciences, Multidisciplinary)no abstracts in English
Yasue, Kenichi; Asamori, Koichi; Tanikawa, Shinichi; Yamada, Kunimi; Yamasaki, Seiko; Kokubu, Yoko; Niwa, Masakazu; Doke, Ryosuke; Kusano, Tomohiro; Hanamuro, Takahiro; et al.
JAEA-Research 2011-023, 113 Pages, 2011/10
JAEA-Research-2011-023.pdf:10.9MB
This annual report documents the progress of R&D in the first fiscal year during the JAEA 2nd Midterm Plan (FY 2010 - 2014) to provide the scientific base for assessing geosphere stability for long-term isolation of the high-level radioactive waste. The planed framework is structured into the following categories: (1) development and systematization of investigation techniques for selecting suitable sites in geosphere stability, (2) development, application and verification of prediction models for evaluating the changes of geological environment in thermal, hydraulic, mechanical and geochemical conditions for a long period of time, and (3) development of new dating techniques for providing information about geologic history and the timing of geologic events. In this paper, the current status of R&D activities with previous scientific and technological progress is summarized.
Yasue, Kenichi; Asamori, Koichi; Kusano, Tomohiro; Kokubu, Yoko; Tanikawa, Shinichi; Niwa, Masakazu; Hanamuro, Takahiro; Yamasaki, Seiko; Yamada, Kunimi; Ishimaru, Tsuneari; et al.
JAEA-Review 2011-023, 43 Pages, 2011/07
JAEA-Review-2011-023.pdf:1.84MB
The concept of geological disposal of HLW in Japan is based on a multibarrier system which combines a stable geological environment with an engineered barrier system. Potential geological host formations and their surroundings are chosen, in particular, for their long-term stability, taking into account the fact that Japan is located in a tectonically active zone. This report is a plan of research and development (R&D) for geosphere stability for long-term isolation of HLW in JAEA, in fiscal year 2011. The objectives and contents in fiscal year 2011 are described in detail based on the outline of 5 years plan (fiscal years 2010-2014). In addition, the plan framework is structured into the following categories: (1) Development and systematization of investigation techniques, (2) Development of models for long-term estimation and effective assessment, (3) Development of dating techniques.
Kusano, Tomohiro; Asamori, Koichi; Kurosawa, Hideki; Kokubu, Yoko; Tanikawa, Shinichi; Negi, Tateyuki; Hanamuro, Takahiro; Yasue, Kenichi; Yamasaki, Seiko; Yamada, Kunimi; et al.
JAEA-Research 2010-044, 153 Pages, 2011/01
JAEA-Research-2010-044.pdf:12.53MB
This progress report (H22 report) documents progress made during JAEA 1st Midterm Plan (FY 2005 - 2009) to provide the scientific base for assessing geosphere stability for long-term isolation of the high-level radioactive waste. For the current 5-year R&D programme, three major goals have been defined as follows: (1) development and synthesis of investigation techniques for selecting suitable sites in geosphere stability, (2) development, application, and evaluation of prediction models for evaluating the changes of geological environment in thermal, hydraulic, mechanical and geochemical conditions for a long period of time, and (3) development of new dating techniques for providing information about geologic history and the timing of geologic events. In this paper, the current status of R&D activities with previous scientific and technological progress is summarized.
Yasue, Kenichi; Asamori, Koichi; Yamada, Kunimi; Kokubu, Yoko; Yamasaki, Seiko; Kurosawa, Hideki; Tanikawa, Shinichi; Negi, Tateyuki; Kusano, Tomohiro; Hanamuro, Takahiro; et al.
JAEA-Review 2010-034, 42 Pages, 2010/09
JAEA-Review-2010-034.pdf:1.15MB
The concept of geological disposal of HLW in Japan is based on a multibarrier system which combines a stable geological environment with an engineered barrier system. Potential geological host formations and their surroundings are chosen, in particular, for their long-term stability, taking into account the fact that Japan is located in a tectonically active zone. This report is a plan of research and development (R&D) for geosphere stability for long-term isolation of HLW in JAEA, in fiscal year 2010. The objectives and contents in fiscal year 2010 are described in detail based on the outline of 5 years plan (fiscal years 2010-2014). In addition, the plan framework is structured into the following categories: (1) Development and systematization of investigation techniques, (2) Development of models for long-term estimation and effective assessment, (3) Development of dating techniques.
Umeda, Koji; Ishimaru, Tsuneari; Yasue, Kenichi; Asamori, Koichi; Yamada, Kunimi; Kokubu, Yoko; Hanamuro, Takahiro; Tanikawa, Shinichi; Kusano, Tomohiro
JAEA-Review 2010-030, 48 Pages, 2010/09
JAEA-Review-2010-030.pdf:1.42MB
The concept of geological disposal of HLW in Japan is based on a multibarrier system which combines a stable geological environment with an engineered barrier system. Potential geological host formations and their surroundings are chosen, in particular, for their long-term stability, taking into account the fact that Japan is located in a tectonically active zone. This report is to outline 5 years plan (fiscal years 2010-2014) of research and development (R&D) for geosphere stability for long-term isolation of the high-level radioactive waste in JAEA. Background of this research are clarified with the necessity and the significance, and the past progresses in this report. The objectives, outline, contents and schedule during the next 5 years are described in detail. In addition, the plan framework is structured into the following categories: (1) Development and systematization of investigation techniques, (2) Development of models for long-term estimation and effective assessment, (3) Development of dating techniques.
Kusano, Tomohiro; Asamori, Koichi; Kurosawa, Hideki; Tanikawa, Shinichi; Ninomiya, Atsushi; Negi, Tateyuki; Hanamuro, Takahiro; Yasue, Kenichi; Yamada, Kunimi; Ishimaru, Tsuneari; et al.
JAEA-Research 2009-072, 72 Pages, 2010/03
JAEA-Research-2009-072.pdf:11.27MB
The Japanese islands are located in the tectonically active Circum-Pacific Mobile Belt. As a result, Japan has a high frequency of earthquakes and eruptions. Special consideration is given to the long-term stability of the geological environment, taking into account volcanism, faulting, uplift, denudation, climatic change and sea-level change in Japan. Development of research/prediction technologies for geotectonic events has been carried out to evaluate the long-term stability of the geological environment in Japan. In fiscal year 2008, we carried out the following researches. For studies on faulting and seismic activity, we developed investigation techniques for evolutional history and activity of fault, and carried out case studies for development of effective assessment model in the fault zones. For volcanological and geothermal studies, we provided an integrated approach for detecting crustal magma and/or geothermal fluid in deep underground using geophysical and geochemical data. For the general evaluation study on uplift/denudation and climatic/sea-level change, we arranged investigation techniques for reconstruction of paleo-topography and paleo-climate, and to establish a simulation model for landform development. For studies on the long-term stability of the geological environments, we developed simulation techniques for groundwater flow related by crustal movement.
Kusano, Tomohiro; Nohara, Tsuyoshi; Umeda, Koji; Ishimaru, Tsuneari; Hanamuro, Takahiro; Saito, Tatsuo; Yasue, Kenichi; Niwa, Masakazu; Shimada, Koji; Yamada, Kunimi; et al.
JAEA-Research 2009-022, 47 Pages, 2009/09
JAEA-Research-2009-022.pdf:48.94MB
The Japanese islands are located in the tectonically active Circum-Pacific Mobile Belt. As a result, Japan has a high frequency of earthquakes and eruptions. Special consideration is given to the long-term stability of the geological environment, taking into account volcanism, faulting, uplift, denudation, climatic change and sea-level change in Japan. Development of research/prediction technologies for geotectonic events has been carried out to evaluate the long-term stability of the geological environment in Japan. In fiscal year 2007, we carried out the following researches, to confirm existence of the phenomena that have influences on geological disposal system (e.g., active faulting, volcanism), and to develop the investigation techniques to reconstruct the history of these phenomena. For studies of faulting and seismic activity, we developed the investigation techniques to research distribution of crush zone, process of faulting, activity, and so on. For volcanological and geothermal studies, we developed a technique for detecting crustal magma and/or geothermal fluid in deep underground. For studies of uplift/denudation and climatic/sea-level changes, we extracted investigation techniques for landform developments and uplift rate with river terraces.
Nohara, Tsuyoshi; Umeda, Koji; Sasao, Eiji; Hanamuro, Takahiro; Saito, Tatsuo; Yasue, Kenichi; Niwa, Masakazu; Mashima, Hidehisa*; Shimada, Koji; Yamada, Kunimi; et al.
JAEA-Research 2008-062, 61 Pages, 2008/07
JAEA-Research-2008-062.pdf:39.02MB
The Japanese islands are located in the tectonically active Circum-Pacific Mobile Belt. As a result, Japan has a high frequency of earthquakes and eruptions. Special consideration is given to the long-term stability of the geological environment in Japan. Development of research/prediction technologies for geotectonic events has been carried out to evaluate the long-term stability of the geological environment in Japan. During fiscal year 2006, we carried out the following researches, to confirm existence of the phenomena that have influences on geological disposal system, and to develop the research techniques to reconstruct the history of these phenomena. For studies of active faulting and seismic activity, we reviewed the existing techniques to research past activities and distribution of active faults (migration, extension, development process of a deformation zone). For volcanological and geothermal studies, we extracted a technique for detecting crustal magma and/or geothermal fluid in deep underground using geophysical and geochemical data, and models assessing the likelihood of future volcanism and its influence on geological environment. For studies of uplift/denudation and climatic/sea-level change, we constructed conceptual models such as landform development model.
Yamada, Kunimi; Tagami, Takahiro*
Journal of Geophysical Research, 113(3), p.B03402_1 - B03402_10, 2008/03
We performed new thermochronometry for the Tanzawa Tonalite Complex to investigate the exhumation history caused by arc-arc collision. Typical (U-Th)/He ages were 2.0 
0.2 Ma on apatite and 3.3 0.2 Ma on zircon and 4.5 to 6.9 Ma on zircon using the fission-track method. The exhumation rate has been calculated to be 0.5 to 1.5 mm/yr from 
7 to 3.3 Ma, 2 mm/yr from 3.3 to 2.0 Ma and 0.8 mm/yr from 2.0 to 0 Ma with an assumed geothermal gradient of 40
C/km. The exhumation rate has not changed significantly despite the simultaneous tectonic changes around the Tanzawa Mountains after 7 Ma.
Umeda, Koji; Hanamuro, Takahiro; Yamada, Kunimi; Negishi, Yoshimitsu*; Iwano, Hideki*; Danhara, Toru*
Radiation Measurements, 42(10), p.1647 - 1654, 2007/11
Times Cited Count：2 Percentile：18.95(Nuclear Science & Technology)Fission track dating of zircon and apatite samples from the altered host rocks around three hot springs were carried out in order to elucidate the thermochronology of the hydrothermal system in this non-volcanic region. The apatite FT ages from the altered host rocks around the hot springs ranged from 2.7 to 5.6 Ma, which are significantly younger than the 12 Ma age of the non-altered host rocks far from the hot springs. In the southern Kii Peninsula, therefore, it is obvious that the non-volcanic hydrothermal activity already has been ongoing since around 6 Ma.
Yamada, Kunimi; Hanamuro, Takahiro
no journal, ,
no abstracts in English
Yamada, Kunimi
no journal, ,
no abstracts in English
Yamada, Kunimi; Hanamuro, Takahiro; Tagami, Takahiro*; Yamada, Ryuji*; Umeda, Koji
no journal, ,
Japan Atomic Energy Agency have jointly set up the lab of the (U-Th)/He dating in cooperation with Kyoto University. At the present stage, samples are apatite and zircon. Infrared laser heating in vacuum chamber extracts helium. The helium is quantified using the MM5400 rare gas mass spectrometer and the sensitivity method. The sensitivity of the mass spectrometer is calibrated using standard air, a volume-known pipette, and a capacitance manometer. The ICP quadrupole mass spectrometer quantifies uranium and thorium using standard addition method after dissolution of the gas-extracted sample. Apatite is dissolved using HNO
and zircon is decomposed by the alkali-fusion method using XRF bead sampler and LiBO. We are performing the calibration of MM5400 and testing dissolution procedures for ICP at present, and will report detailed views of dating systems in addition to them.
Yamada, Kunimi; Hanamuro, Takahiro; Tagami, Takahiro*; Yamada, Ryuji*; Umeda, Koji
no journal, ,
no abstracts in English
Yamada, Kunimi; Hanamuro, Takahiro; Tagami, Takahiro*; Yamada, Ryuji*; Umeda, Koji
no journal, ,
In 1987, it was revealed that the (U-Th)/He ages of apatites might be cooling ages with very low temperature cooling. Because of the suggested useful possibility in geo- and thermochronology, the (U-Th)/He method has been quickly developed since 1990's. The (U-Th)/He method mainly applies to investigate the last event on a cooling or exhumation history of present rapid orogen and a thermal anomaly through an active fault at the present. Japan Atomic Energy Agency have jointly set up the lab of the (U-Th)/He dating in cooperation with Kyoto University and NIED. At the present stage, the accuracy and precision are roughly 20 and 10%, respectively, using the age known zircon from the Fish Canyon Tuff (FC3). In the presentation, we will introduce the ages of some age known samples.
