Physicochemical characterization of the youngest active domain in major fault zones using the weathering index and X-ray computed tomography

Iwamori, Akiyuki*; Ogita, Yasuhiro; Shimada, Koji; Tateishi, Ryo*; Takagi, Hideo*; Ota, Toru*; Cho, T.*; Kudo, Shunsuke*; Nojiri, Keisuke*; Shigemitsu, Yasumune*; et al.

Engineering Geology, 344, p.107821_1 - 107821_20, 2025/01

https://doi.org/10.1016/j.enggeo.2024.107821

Clarification of the physicochemical characterization of brittle fault rocks is important not only for understanding the history of the fault activity and deformation mechanisms, but also for assessing the siting conditions of important facilities such as nuclear power plants, radioactive waste disposal sites, and oil storage bases. Here, we apply the chemical weathering index (W values) to the brittle fault rocks of the Shiraki-Nyu fault (granite), the Tsuruga fault (geological boundary between granite and greenstone), and the Yamada fault (adamellite), which are active faults in the peripheral area of Wakasa Bay, and their respective protoliths (hard rocks), and investigate the physicochemical characteristics of the youngest active domain of brittle fault rocks based on the relationship between computed tomography data (CT numbers) and alteration intensity (AI values). The W values of the fault rocks are mainly affected by changes in NaO and CaO, corresponding to the elution or deposition of plagioclase and calsite for granite, clinopyroxene and hornblende for greenstone, and plagioclase for adamellite. The W values mainly indicate the effects of hydrothermal alteration up to 50 60 percent and of weathering at over 60 percent. On the other hand, the CT values of the fault rocks are lowest in the fault gouge corresponding to the latest active zone, which was identified as the lowest density zone. In addition, fresh plagioclase fragments are present in each fault gouge of the latest active zone of the active faults in this study. The application of W values to brittle fault rocks is an effective method for understanding the trends of mineralogical variations associated with hydrothermal alteration and weathering in fault rocks, and it is highly possible to improve the accuracy of identifying the youngest active domain in major fault zones through joint analyses of CT numbers.

Conduction-band electronic states of YbInCu studied by photoemission and soft X-ray absorption spectroscopies

Utsumi, Yuki*; Sato, Hitoshi*; Kurihara, Hidenao*; Maso, Hiroyuki*; Hiraoka, Koichi*; Kojima, Kenichi*; Tobimatsu, Komei*; Okochi, Takuo*; Fujimori, Shinichi; Takeda, Yukiharu; et al.

Physical Review B, 84(11), p.115143_1 - 115143_7, 2011/09

https://doi.org/10.1103/PhysRevB.84.115143

We have studied conduction-band (CB) electronic states of a typical valence-transition compound YbInCu by means of temperature-dependent hard X-ray photoemission spectroscopy (HX-PES), soft X-ray absorption spectroscopy (XAS), and soft X-ray photoemission spectroscopy (SX-PES) of the valence band. We have described the valence transition in YbInCu in terms of the charge transfer from the CB to Yb 4 states.

X-ray magnetic circular dichroism and photoemission studies of ferromagnetism in CaMnRuO thin films

Terai, Kota*; Yoshii, Kenji; Takeda, Yukiharu; Fujimori, Shinichi; Saito, Yuji; Owada, Kenji; Inami, Toshiya; Okane, Tetsuo; Arita, Masashi*; Shimada, Kenya*; et al.

Physical Review B, 77(11), p.115128_1 - 115128_6, 2008/03

https://doi.org/10.1103/PhysRevB.77.115128

Electronic structure and magnetism of CaMnRuO thin films

Terai, Kota; Yoshii, Kenji; Takeda, Yukiharu; Fujimori, Shinichi; Saito, Yuji; Owada, Kenji; Inami, Toshiya; Okane, Tetsuo; Arita, Masashi*; Shimada, Kenya*; et al.

Journal of Magnetism and Magnetic Materials, 310(2, Part2), p.1070 - 1072, 2007/03

We have studied the electronic and magnetic properties of epitaxially grown CaMnRuO (x = 1.0, 0.5) thin films by X-ray magnetic circular dichroism (XMCD) and hard X-ray photoemission spectroscopy (HXPES). The XMCD studies indicated that the spin moments of Mn and Ru are aligned in the opposite directions. The HXPES spectra indicated the Ru 4d states at around the Fermi edge (E) and the Mn 3d states below E. From these results, we propose that the localized Mn 3d t states and the itinerant Ru 4d t band are antiferromagnetically coupled and give rise to ferromagnetism, in analogy with the mechanism proposed for the double perovskite oxides such as SrFeMoO.

Characterization of extreme ultraviolet emission from laser-produced spherical tin plasma generated with multiple laser beams

Shimada, Yoshinori*; Nishimura, Hiroaki*; Nakai, Mitsuo*; Hashimoto, Kazuhisa*; Yamaura, Michiteru*; Tao, Y.*; Shigemori, Keisuke*; Okuno, Tomoharu*; Nishihara, Katsunobu*; Kawamura, Toru*; et al.

Applied Physics Letters, 86(5), p.051501_1 - 051501_3, 2005/01

https://doi.org/10.1063/1.1856697

no abstracts in English

Particle confinement and transport in JT-60U

Takenaga, Hidenobu; Nagashima, Keisuke; Sakasai, Akira; Asakura, Nobuyuki; Shimizu, Katsuhiro; Kubo, Hirotaka; Higashijima, Satoru; Oikawa, Toshihiro; Fujita, Takaaki; Kamada, Yutaka; et al.

Fusion Energy 1998, Vol.2, p.749 - 752, 1998/10

no abstracts in English

Improved divertor confinement observed in JT-60

Tsuji, Shunji; Hosogane, Nobuyuki; Itami, Kiyoshi; Kubo, Hirotaka; Nishitani, Takeo; Shimada, Michiya; Koide, Yoshihiko; ; Sugie, Tatsuo; Nagashima, Keisuke; et al.

JAERI-M 91-195, 47 Pages, 1991/11

JAERI-M-91-195.pdf:1.31MB

no abstracts in English

Observation of limiter H mode in the JT-60 tokamak with lower hybrid current drive

Tsuji, Shunji; Ushigusa, Kenkichi; Ikeda, Yoshitaka; Imai, Tsuyoshi; Itami, Kiyoshi; Nemoto, Masahiro; Nagashima, Keisuke; Koide, Yoshihiko; Kawano, Yasunori; Fukuda, Takeshi; et al.

Physical Review Letters, 64(9), p.1023 - 1026, 1990/02

https://doi.org/10.1103/PhysRevLett.64.1023

no abstracts in English

None

Tsukamoto, Taisuke*; Konishi, Yuki*; Nishimura, Keisuke*; Ban, Yasutoshi; Tsubata, Yasuhiro; Nakase, Masahiko*; Shimada, Takashi*; Yamamura, Tomoo*

no journal, , 

no abstracts in English

None

Shimada, Takashi*; Yamamura, Tomoo*; Harigai, Miki*; Takeshita, Kenji*; Nakase, Masahiko*; Okamura, Tomohiro*; Ban, Yasutoshi; Tsukamoto, Hiroki*; Nishimura, Keisuke*; Gima, Hiromichi*

no journal, , 

no abstracts in English