Petrography and geochronology of the Kuki granite, Kitakami mountains, northeastern Japan; Shallow crustal intrusion and emplacement processes of granitic magma

Suzuki, Satoshi*; Yuguchi, Takashi*; Ishiguro, Keito*; Endo, Kyoka*; Kato, Asuka*; Yokoyama, Kosuke*; Ogita, Yasuhiro; Yokoyama, Tatsunori; Sakata, Shuhei*; Ono, Takeshi*; et al.

Journal of Mineralogical and Petrological Sciences (Internet), 119(1), p.230807_1 - 230807_18, 2024/02

https://doi.org/10.2465/jmps.230807

Understanding the crustal evolutionary dynamics of island arc-trench systems requires a thorough evaluation of magma chamber processes, and especially of shallow crustal granitic magma intrusion and emplacement processes. To address this, we studied the petrography and geochronology of the Kuki granite, Kitakami Mountains, northeast Japan, as an example of a non-adakitic granite at the magmatic flare-up stage. Granitic borehole samples reflect vertical variation within a magma chamber. Whole-rock chemical composition and mode data reveal a vertical transition from felsic to mafic composition with increasing depth, potentially due to gravitational fractionation of crystals in the magma chamber. The pressure and temperature history of the Kuki granite indicates no change in the magma depth with cooling from 800 to 730C, and geobarometric calculations indicate the emplacement of magma at a depth of approximately10 km. Simultaneous determination of the zircon U Pb age, Ti concentration, and Th/U yields 1) the time temperature history of granitic magma before its solidification, and 2) the correlation between temperature and Th/U in the magma. The magma chamber cooled from ca. 900 to 700C at approximately 125 Ma. The change in Th/U with temperature indicates greater fractional crystallization in the magma chamber at temperatures above 800C than below 800C. Samples from different depth exhibit common tendencies in terms of the relationship between Th/U and temperature, indicating the same system of fractional crystallization throughout the cooling magma chamber.

Enhancement of the methodology of repository design and post-closure performance assessment for preliminary investigation stage; Progress report on NUMO-JAEA collaborative research in FY2011 (Joint research)

Shibata, Masahiro; Sawada, Atsushi; Tachi, Yukio; Makino, Hitoshi; Hayano, Akira; Mitsui, Seiichiro; Taniguchi, Naoki; Oda, Chie; Kitamura, Akira; Osawa, Hideaki; et al.

JAEA-Research 2012-032, 298 Pages, 2012/09

JAEA-Research-2012-032.pdf:33.68MB

JAEA and NUMO have conducted a collaborative research work which is designed to enhance the methodology of repository design and performance assessment in preliminary investigation phase. The topics and the conducted research are follows; (1) Study on selection of host rock: in terms of hydraulic properties, items for assessing rock property, and assessment methodology of groundwater travel time has been organized with interaction from site investigation. (2) Study on development of scenario: the existing approach has been embodied, in addition, the phenomenological understanding regarding dissolution of and nuclide release from vitrified waste, corrosion of the overpack, long-term performance of the buffer are summarized. (3) Study on setting nuclide migration parameters: the approach for parameter setting has been improved for sorption and diffusion coefficient of buffer/rock, and applied and tested for parameter setting of key radionuclides. (4) Study on ensuring quality of knowledge: framework for ensuring quality of knowledge has been studied and examined aimed at the likely disposal facility condition.

A Study and Modeling about Ground Water Flow Considering the Properties of Sedimentary Soft Rock

Inoue, Hiroyuki*; Ishiguro, Takeshi*; Kuji, Masayoshi*; Yoshino, Naoto

JNC TJ8400 2004-013, 137 Pages, 2004/02

JNC-TJ8400-2004-013.pdf:22.48MB

In this paper, authors examined the properties of sedimentary soft rock which might affect the groundwater flow rate and flow path in the sedimentary soft rock. As a general sample of sedimentary soft rock, we focused on the rock of HORONOBE area in HOKKAIDO prefecture. Then, following four issues were examined. 1) a study of numerical flow rate analysis considering the difference of water density in the sedimentary soft rock. 2) the hydro-geological modeling of HORONOBE area and a fundamental study of water pressure and saline density in HORONOBE area. 3) a fundamental study of numerical coupling analysis about groundwater flow rate ,the difference of underground temperature, rock pressure and deformation. 4) a study about best performance of numerical flow rate analysis program. As a result, hydro-geological modeling of HORONOBE area using the information before 2002 as input data was succeeded by using the basic geological model which was made by IMAI et al,. And the applicability of TOUGH2 program as analysis method considering the density difference of underground water in sedimentary soft rock was verified. Then, we will be able to simulate underground flow considering the difference of saline density and specific water pressure in HORONOBE area. In addition, the applicability of TOUGH-FLAC program in which TOUGH2 was coupled with FLAC3D and consider rock pressure and deformation was verified. The best numerical performance of TOUGH2 program was studied in order to deal with large scale simulations. Then, it was shown that efficient method of the best numerical performance about TOUGH2 was possible.

None

; Kanno, Takeshi; Ishikawa, Hirohisa; Ishiguro, Katsuhiko

PNC TN8410 97-051, 53 Pages, 1997/02

PNC-TN8410-97-051.pdf:1.4MB

None

None

Sugita, Yutaka; Kanno, Takeshi; Ishikawa, Hirohisa; Ishiguro, Katsuhiko

PNC TN8410 96-014, 46 Pages, 1995/12

PNC-TN8410-96-014.pdf:0.08MB

None

Electrical characterization of GaN containing nitrogen vacancies introduced by electron irradiation

Kato, Masashi*; Fukushima, Keisuke*; Kasuga, Masanobu*; Kito, Kosuke*; Ichimura, Masaya*; Kanechika, Masakazu*; Ishiguro, Osamu*; Kachi, Tetsu*; Oshima, Takeshi

no journal, , 

no abstracts in English