著者
柿谷 悟
出版者
地理科学学会
雑誌
地理科学 (ISSN:02864886)
巻号頁・発行日
vol.21, pp.1-9, 1974 (Released:2017-04-14)

The author has been studying the causal relationship between natural hazards due to geological processes and the effects of heavy rainfalls on weathered granite during past five years. It was recognized that there was a close relationship between the present topography and the condition of weathered rock. The purpose of this paper is to discuss the relationship between a form of rock weathering and the topography of Hiroshima Prefecture and adjacent areas. As a study model, six layers excluding regolith and "idomasa" (colluvium composed of weathered granite) were clearly defined in the horizon of weathered granite: Chemical Weathered Layers I, II and III, and Physical Weathered Layers I, II and III, downwards. The present field investigations indicate that the deep weathered zone is found on the flat surfaces in different elevations such as on the Setouchi, the Sera and the Kibi Surfaces. Further considerations have been extended to the distribution of the deep weathered areas, the formation processes of the present topography and the geological time in which the deep weathering processes were active. It is proposed that the crustal movements which were due to the compression in a N-S direction during the early stage, and in a E-W direction during the later stage have strongly influenced the development of the landforms since the Pliocene.
著者
山口 一裕 西本 憲正 三宅 寛 柿谷 悟 光藤 裕之
出版者
岡山理科大学
雑誌
岡山理科大学紀要. A, 自然科学 (ISSN:02857685)
巻号頁・発行日
vol.31, pp.147-153, 1995
被引用文献数
1

"Kinsai/Ginsai" is one of fascinating patterns of Bizen-yaki and rarely appears. The formation mechanism of "Kinsai/Ginsai" has been investigated to improve reproducibility on the formation of "Kinsai/Ginsai". "Kinsai/Ginsai" is reproduced by forming carbon film on the surface of Bizen-yaki body or mica in the vacuum evaporator. The color on Bizen-yaki body or mica gradually changed from silver to gold in proportion to the increasing thickness of carbon film. The thickness of carbon film on mica, which was measured by the Aomic Force Microscope (AFM), ranges from 10 to 20nm in silver and from 40 to 50nm in gold.
著者
小林 祥一 坂本 尚史 柿谷 悟
出版者
日本粘土学会
雑誌
粘土科学 (ISSN:04706455)
巻号頁・発行日
vol.33, no.2, pp.81-91, 1993-08-31
被引用文献数
8

An artificial chemical weathering of a polished plate of granite from Kitagi, Okayama Prefecture, Japan was conducted using a Soxhlet extraction apparatus with distilled water and HNO_3 solution of pH 4 at 50℃ for a different period of time up to 189 days. The granite was composed mainly of quartz, plagioclase (Ab_<86>An_<12>Or_2), alkali feldspar (Or_<92>Ab_8) and biotite. The results showed the release of elements and the degree of weathering of minerals as a function of leaching time. Among the all minerals, biotite showed the higher chemical weathering that was enhanced by the HNO_3 solution. The chemistry of the surface of each mineral shows a characteristic change during the chemical weathering as follows : 1) The ratios (Mg+Fe+Mn+Cr) / Al in the octahedral sheet and (K+Na+Ca) / (Total Al) in the interlayer of biotite decrease with the increase of leaching time, but the ratio (Si+Ti) / Al in the tetrahedral sheet is not changed ; 2) The tatio (Na+Ca+K) / Al for plagioclase decreases with the increase of leaching time. Smectite, containing a small amount of iron, was developed from the alteration of plagioclase during the chemical weathering by the HNO_3 solution.
著者
柿谷 悟 藤坂 正良
出版者
公益社団法人日本セラミックス協会
雑誌
窯業協會誌 (ISSN:18842127)
巻号頁・発行日
vol.66, no.750, pp.133-139, 1958-06-01
被引用文献数
3

In order to build up a background to the relative difficulty for burning the different raw materials in cement production the solid phase reactions between SiO<sub>2</sub> and either CaCO<sub>3</sub> or BaCO<sub>3</sub> at the temperatures ranging 500°-800°C were studied by measuring the amount of CO<sub>2</sub> liberated during the reaction. Then, applying the figures so obtained into the Jander's equation for solid phase reaction the authors have tried to work out the rate constants as well as the activation energies. However, it was found out that there were many examples which failed to fit in the equation, probably, due to the additional CO<sub>2</sub> liberated by simple thermal dissociation of the carbonates.<br>On the other hand, W. E. S. Turner et al. have suggested the acceleration of thermal dissociation of CaCO<sub>3</sub> when it was mixed with the powder of silica or of pure gold. The same trend was confirmed to exist also in the case of BaCO<sub>3</sub>.<br>Furthermore, the investigation of X-ray diffraction pattern has revealed that the reaction products of CaCO<sub>3</sub> and SiO<sub>2</sub> obtained by heating at 700°C in air for 242 hours was not wollastonite (βCaO⋅SiO<sub>2</sub>) but larnite (β2CaO⋅SiO<sub>2</sub>).