Presumption of the distribution of the geological structure based on the geological survey and the topographic data in and around the Horonobe area

Sakai, Toshihiro; Matsuoka, Toshiyuki

JAEA-Research 2015-004, 109 Pages, 2015/06

JAEA-Research-2015-004.pdf:141.42MB
JAEA-Research-2015-004-appendix(CD-ROM).zip:128.66MB

We update the geologic map and the database of the geological mapping published by Funaki et al. (2005a) and Ota et al. (2007) based on geological survey and topographical analysis data in and around the Horonobe area. There are many geological survey data which are derived from natural resources (petroleum, natural gas and coal, etc.) exploration in and around Horonobe-cho. We also use these data in addition to data in Funaki et al. (2005a) and Ota et al. (2007)'s data. As results of this report, we also construct a digital geologic map and a digital database of geological survey using GIS. These results can be expected to improve the precision of modeling and analyzing of geological environment, and its long-term evaluation.

Porosity and Density of Fractured Zone at the Kamaishi Mine

Sato, Haruo

JNC TN8400 99-061, 9 Pages, 1999/10

JNC-TN8400-99-061.pdf:1.43MB

The porosities and dry densities for rock samples sampled from a fractured zone (fracture type C: composed of intact ganodiorite, altered ganodiorite and fracture fillings) at the Kamaishi mine were obtained by a water saturation (intrusion) method as input parameters for nuclide migration analysis in performance assessment of the geological disposal of high-level radioactive waste. Consequently, the average porosity, 8.60.43% was higher than those of fracture fillings, altered garnodiorite and intact ganodiorite composing fracture type B with a single fracture taken from the Kamaishi mine so far. While, the average dry density, 2.430.0089 Mgm, was lower than those of rocks composing the fracture type B. Based on this, it is predicted that radionuclides are the easiest to migrate in the fracture zone.

None

Yamanoi, Tadayo*; *; Okazaki, Hikoya

PNC TJ7361 96-003, 157 Pages, 1996/03

PNC-TJ7361-96-003.pdf:1.78MB

None

None

Kawamura, Kazuo*; Nakajima, Tatsuya*; Tomori, Masahiko*

PNC TJ7361 93-004, 91 Pages, 1993/03

PNC-TJ7361-93-004.pdf:8.99MB

no abstracts in English

Data collection and predictive analysis of volcanic dykes distribution

Kawamura, Makoto; Jia, H.*; Koizumi, Yukiko*; Niwa, Masakazu; Umeda, Koji*

no journal, , 

One of the issues related to volcanic and igneous activities in the safety assessment of geological disposal of HLW is the sophistication of technology for grasping the range of influence of magma. To address this issue, it is necessary to accumulate data, especially when the dike extends over a radius of 15 km from the center of the Quaternary volcano. However, it is practically difficult to grasp the distribution of the conduits underlying the existing volcanic bodies and the dikes derived from them. In field geological surveys, small outcrops with intrusive dikes may be found even in places away from Quaternary volcanoes. Whether such dikes are associated with nearby Quaternary volcanoes is important in assessing the extent of the dikes. We extracted "dike" from the geological map width published by the AIST, and tried to evaluate its relevance to the surrounding Quaternary volcanoes. As a preliminary study, we used Daisen, a Quaternary volcano in the Chugoku region. The distribution of dikes is digitally traced, GIS data is created and organized on a white map, and then "position (latitude / longitude)", "size (major axis / minor axis, etc.)", "era", "rock type", "dike intrusion stratum name, era" and "nearest volcano name, distance from crater" were extracted. As a result, 151 volcanic dykes were extracted. The dikes associated with Quaternary volcanoes are limited to new Daisen volcanic ejecta (parasitic volcanoes), and their distribution is also limited to the Daisen volcano. All dikes located far from the volcano are determined to have been formed before the Neogene. Some of them are lava, but some are deep-seated rocks such as dolerite and diorite. A relatively large number of pre-Neogene dikes show a lenticular distribution morphology, and the dikes of acid rocks are the main constituents. This suggests that dikes formed deeper than the Quaternary became visible on the surface due to denudation.

Data collection and predictive analysis of volcanic dykes distribution (Continuation)

Kawamura, Makoto; Jia, H.*; Koizumi, Yukiko*; Niwa, Masakazu; Umeda, Koji*

no journal, , 

Volcanic dykes were extracted from a geological map of 1 / 200,000 and location information was converted into GIS data. The number of volcanic dykes extracted was 593 in the Chugoku region, 228 in the Shikoku region, and 308 in the Oshima Peninsula in the southern part of Hokkaido. More than half of the major axis lengths of rock veins are less than 1km, and more than 80% including those less than 2km. Some rock veins exceed 10km, but they are distributed around the cauldron. The distribution of quaternary volcanic dykes exposed on the surface of the three areas is limited to within 10km from the quaternary volcano. Regarding the relationship between the quaternary volcano and the dykes older than the quaternary period, it is considered that the relationship is low as a result of examining the relationship such as the distance and the extension direction of the dykes. We also examined the relationship between Neogene-Tertiary volcanic activity and the dykes distributed in the surrounding area. In the case of Ishizuchi Cauldron, it was shown that the maximum distance from the related rock veins was about 5km. On the other hand, it was found that the dykes of the Kibi Plateau in the Chugoku region are distributed within a range of approximately 15km from the central point of activity. Comprehensive information gathering as described above and statistical examination using them are useful as basic information for investigating and evaluating the range of influence of magma in the geological disposal.