Updated on 2022/05/17


Faculty of Science and Engineering, School of Creative Science and Engineering
Job title

Concurrent Post

  • Faculty of Science and Engineering   Graduate School of Creative Science and Engineering

Research Institute

  • 2020

    理工学術院総合研究所   兼任研究員


  • 1982.12

    Universite Catholique de Louvain   Faculty of applied Science   Department of Mineralogy and Petrology  

  • 1979.04

    Univesity of Tokyo   Graduate School of Science Doctoral Program   Major in Geology  

  • 1977.04

    Univesity of Tokyo   Graduate School, Division of Science   Major in Geology  

  • 1973.04

    Waseda University   School of Science and Engineering   Department of Mineral Resources Engineering  


  • University of Tokyo   Doctor of Science

  • 東京大学   理学博士

Research Experience

  • 1996

    Waseda Univerisity, Professor

  • 1991

    Waseda University, Assistant Professor

  • 1990

    Waseda University, Associate

  • 1986

    Waseda University, Research Assistant

  • 1988.03

    高麗大学   理学部地質学科   交換研究員

Professional Memberships


    Japan Society for Scientific Studies on Cultural Properties


    The Mining and Materials Processing Institute of Japan


    The Geochemical Society of Japan


    The Geological Society of Japan


    Japan Association of Mineralogical Sciences


    The Society of Resource Geology

▼display all


Research Areas

  • Cultural assets study   クメール遺跡、アンコール遺跡、石材、石材劣化、非破壊分析

  • Solid earth sciences   花崗岩類、熱水性鉱床、鉱物ー熱水間平衡実験

Research Interests

  • Mineralogy, Petrology and Mineral Deposit, Geochemistry, Cultural Asset Science


  • Non-destructive in-situ classification of sandstones used in the Angkor monuments of Cambodia using a portable X-ray fluorescence analyzer and magnetic susceptibility meter

    Etsuo Uchida, Ryota Watanabe, Rathborith Cheng, Yuta Nakamura, Toru Takeyama

    Journal of Archaeological Science: Reports   39   103137 - 103137  2021.10  [Refereed]

    Authorship:Lead author


  • Review of the Mesozoic iron mineralization in South Korea

    Jieun Seo, Seon-Gyu Choi, Young-Jae Lee, Etsuo Uchida

    Journal of the Geological Society of Korea   57 ( 4 ) 615 - 628  2021.08  [Refereed]

  • Zircon U–Pb chronology on plutonic rocks from northeastern Cambodia

    Naoto Kasahara, Sota Niki, Etsuo Uchida, Kosei Yarimizu, Rathborith Cheng, Takafumi Hirata

    Heliyon   7 ( 4 ) 1 - 12  2021.05

    Authorship:Corresponding author


  • Simultaneous partition experiment of divalent metal ions between sphalerite and 1 mol/L (Ni,Mg,Co,Fe,Mn)Cl2 aqueous solution under supercritical conditions.

    Etsuo Uchida, Keiko Wakamatsu, Naoki Takamatsu

    Minerals   11 ( 435 ) 1 - 11  2021.04  [Refereed]

    Authorship:Lead author

  • Experimental investigation of the simultaneous partitioning of divalent cations between löllingite or safflorite and 2 mol/L aqueous chloride solutions under supercritical conditions

    Etsuo UCHIDA, Yoshiki SUGINO, Hiroyuki YOKOYAMA

    Journal of Mineralogical and Petrological Sciences   115 ( 5 ) 1 - 10  2020.10  [Refereed]


  • Simultaneous Partitioning of Divalent Metal Ions between Alabandite and1 mol/L (Ni, Mg, Co, Zn,Fe)Cl2 Aqueous Chloride Solution under Supercritical Conditions

    Etsuo Uchida, Motoki Murasugi, Shuichi Okuda

    Minerals   10 ( 696 ) 1 - 11  2020.08  [Refereed]


  • The Sandstone Quarries of the Angkor Monuments in the Southeastern Foothills of Kulen Mountain.

    Etsuo Uchida, Ryota Watanabe, Motoki Murasugi, Yuichiro Sakurai, Ichita Shimoda

    Archaeological Discovery   8   207 - 227  2020.05  [Refereed]


  • Seasonal and Spatial Variations of Chemical Weathering in the Mekong Basin: From the Headwaters to the Lower Reaches

    Hiroto Kajita, Yuki Ota, Toshihiro Yoshimura, Daisuke Araoka, Takuya Manaka, Ouyang Ziyu, Shinya Iwasaki, Takuya Yanase, Akihiko Inamura, Etsuo Uchida, Hongbo Zheng, Qing Yang, Ke Wang, Atsushi Suzuki, Hodaka Kawahata

    Aquatic Geochemistry     1 - 23  2020.04  [Refereed]


  • Supply ranges of stone blocks used in masonry bridges and their construction period along the East Royal Road in the Khmer Empire, Cambodia

    Etsuo Uchida, Yuichiro Sakurai, Rathborith Cheng, Ichita Shimoda, Yu Saito

    Heritage Science   8 ( 38 ) 1 - 16  2020.04  [Refereed]

  • Petrogenesis and tectonic setting of Late Paleozoic and Late Mesozoic igneous rocks in Cambodia.

    Rathborith CHENG, Etsuo UCHIDA, Masato KATAYOSE, Kosei YARIMIZU, Ki-Cheol SHIN, Sitha KONG, Talanori NAKANO

    Journal of Asian Earth Sciences   185   1 - 21  2019.11  [Refereed]

  • 超臨界条件下における硫砒鉄鉱および輝コバルト鉱と塩化物水溶液間における2価金属イオンの同時分配実験

    内田悦生, 和泉裕也, 渡邊 光

    岩石鉱物科学   48 ( 4 ) 103 - 112  2019.10  [Refereed]


  • Estimated construction order of the major shrines of Sambor Prei kuk based on an analysis of bricks.

    Ichita SHIMODA, Etsuo UCHIDA, Kojiro TSUDA

    Heritage   2   1941 - 1959  2019.07  [Refereed]


  • Chemical compositional signatures of constituent Minerals of iron slags and ores from the Khmer monuments.

    Etsuo Uchida, Motoki Murasugi, Ayaka Kuroda, Yusu Lu

    Heritage   2   1724 - 1738  2019.06  [Refereed]

  • Experiments on rare-earth element extractions from umber ores for optimizing the griding process.

    Yutaro Takaya, Meiqi Wang, Koichiro Fujunaga, Etsuo Uchida, Tatauo Nozaki, Yasunori Kato

    Heritage   9 ( 239 ) 1 - 20  2019.04

  • Approach to skarn deposits

    Etsuo Uchida, Takanori Nakano

    Chikyukagaku   52 ( 4 ) 149-169  2018.12  [Refereed]


  • Construction sequence of the Koh Ker monuments constrained by the chemical composition and magnetic susceptibility of its bricks.

    Uchida, E, Sakurai, Y

    Archaeological Discovery   6   173 - 185  2018  [Refereed]

  • Determining the construction sequence of the Preah Vihear monument in Cambodia from its sandstone block characteristics

    Etsuo Uchida, Akinori Mizoguchi, Hiroya Sato, Ichita Shimoda, Ryota Watanabe

    HERITAGE SCIENCE   5   1 - 15  2017.10  [Refereed]

     View Summary

    The Preah Vihear monument in Cambodia, located close to the border with Thailand, was one of the Khmer temples registered on the UNESCO World Heritage List as a Cultural Property in 2008. It consists of masonry buildings constructed of siliceous sandstone blocks. In this study, the construction sequence of its buildings was inferred from the chemical composition, magnetic susceptibility, and size of the sandstone blocks, along with pediment end style, and the presence or absence of reliefs on the tympana of adjacent buildings. Five construction stages were identified. We revealed that the Western Annex Hall (N2) is the oldest edifice in the Preah Vihear monument. We also reconfirmed that the Preah Vihear monument was constructed over a range of years, spanning the Bakheng style period to the Angkor Wat style period (the end of the 9th century to the end of 12th century). It was clarified that during the construction of Preah Vihear, the style of pediment ends changed from pediments ending in scrolls made from one block, to pediments ending in scrolls made from two blocks, and finally to pediments ending in five-headed nagas. Over the same time span, the size of the sandstone blocks used in construction increased markedly.


  • 超臨界条件下における黄鉄鉱あるいは磁硫鉄鉱と2M塩化物水溶液間での2価金属イオンの同時分配実験

    内田悦生, 秦 佑輔, 上村宙生

    岩石鉱物科学   46   124 - 143  2017

  • Major and trace element chemical compositional signatures of some granitic rocks related to metal mineralization in Japan.

    Uchida, E, Osada, K, Nakao, K

    Open Journal of Geology   7   559 - 576  2017  [Refereed]

  • Precipitation of manganese oxides on the surface of construction materials in the Khmer temples, Cambodia

    Etsuo Uchida, Ryota Watanabe, Satomi Osawa

    HERITAGE SCIENCE   4 ( 16 ) 1 - 17  2016.06  [Refereed]

     View Summary

    Background: In addition to the blackening caused by blue-green algae growth, other black areas on the surface of construction materials (e.g., sandstone, laterite and bricks) are frequently observed in the Khmer temples in Cambodia. A non-destructive on-site investigation was carried out using a portable X-ray fluorescence analyzer (pXRF). In addition, samples were taken from the buildings and were analyzed using an X-ray diffractometer (XRD) and a scanning electron microscope with an energy dispersive X-ray spectrometer, and were observed using a field emission scanning electron microscope.
    Results and conclusions: A non-destructive investigation using the pXRF revealed that this blackening was caused by manganese oxide precipitates. The precipitates contained small amounts of Ni, V, Zn, Y, K, Cl, S, Pb, and Cr. The XRD analysis indicated that the manganese oxides were mainly present as an amorphous phase, but some formed birnessite and todorokite. The manganese precipitates were mostly in a hexagonal plate form (100-300 nm), but some were in a rod-shape, which may have been caused by the activity of manganese oxidizing microbes. Preliminary experiments on removal of manganese oxide precipitates were conducted. The manganese oxide precipitates could be easily removed using a reducing agent such as an oxalic acid solution.


  • W-11 ASEAN-Japan Build-Up Cooperative Education Program for Global Human Resource Development in Earth Resources Engineering(International Session)

    Watanabe Koichiro, Shimada Hideki, Fujimitsu Yasuhiro, Yonezu Kotaro, Sugai Yuichi, Wahyudi Sugeng, Gabo Jillian, Sasaoka Takashi, Tindell Thomas, Yasui Mana, Uchida Etsuo

    JSEE annual conference international session proceedings   2015   60 - 65  2015.09

     View Summary

    The ASEAN-Japan Build-Up Cooperative Education Program for Global Human Resource Development in Earth Resources Engineering (AJ-BCEP) is spearheaded by Kyushu University and supported by universities in Japan and top universities in the Southeast Asian region. The School on the Move Program started in 2013 as part of AJ-BCEP's three step-wise projects, the other two being the International Internship Program and the Double Degree Program. Among the three, the SOM involves the most number of participants, with 35-40 student participants a year from different Japan and ASEAN universities and involvement of at least three universities organizing each leg of the program. The SOM focuses on student mobility and social engagement between Japanese and ASEAN graduate students in the field of earth resources (mining) engineering. Through lectures, field trips and discussions in different countries, the SOM Program has exposed the students to various theories and practices that contributed to their knowledge and expertise as future earth resources engineers or research scientists. The on-going program has contributed extensively to the development of bachelor and master course students in the earth resources field from ASEAN and Japanese universities, by creating bonds both academic and social, for enhanced educative experiences.


  • Experiments on the simultaneous partitioning of divalent cations between columbite and 2M aqueous chloride solution under supercritical conditions.

    Hidemitsu TAKATSUKI, Etsuo UCHIDA, Yusuke ARAI

    Resource Geology   65 ( 3 ) 107 - 115  2015  [Refereed]

  • Regional Differences in the Chemical Composition of Cuneiform Clay Tablets.


    Archaeological Discovery   3 ( 179 ) 207  2015  [Refereed]


  • Blackening of the surfaces of Mesopotamian clay tablets due to manganese precipitation.

    E. Uchida, R. Watanabe

    Archaeological Discovery   2   107 - 116  2014.10


  • Construction sequence of the Koh Ker monuments in Cambodia deduced from the chemical composition and magnetic susceptibility of its laterites

    Etsuo Uchida, Kojiro Tsuda, Ichita Shimoda

    HERITAGE SCIENCE   2   1 - 11  2014  [Refereed]

     View Summary

    Introduction: Koh Ker, one of the provincial cities of the Khmer Empire, was located approximately 85 km northeast of the Angkor monuments. The temples in the Koh Ker monuments were mainly constructed from laterite, sandstone and brick between 921 and 944 AD. The laterites used in the Koh Ker monuments are difficult to classify based on their appearance. However, using a portable X-ray fluorescence analyzer it was possible to distinguish two distinct types of laterite based on Sr content.
    Results: Laterite blocks used in construction of the Koh Ker monuments either had a low Sr content of less than 300 ppm or a high Sr content of greater than 400 ppm. Significant quantities of quartz were observed in the low Sr content laterites, whereas the high Sr content laterites had relatively low quartz content. Differences in the magnetic susceptibility also were observed for these laterites. Using both Sr contents and magnetic susceptibilities of the laterite blocks, in combination with the assumption that the construction site proceeded in an outward manner, we identified five distinct laterite types associated with different stages of construction.
    Conclusions: Five different stages of construction were identified in the buildings of the Koh Ker monuments; each stage is characterized by a different laterite source rock. We believe that the brick sanctuaries are the oldest buildings, followed by the sandstone sanctuaries, while the laterite sanctuaries were constructed last. The laterite blocks with high Sr content were likely supplied from quarries around the Srayang village, which is located immediately to the south of the Koh Ker monuments; provenance of the low Sr content laterites is yet to be determined.



    E. Uchida, K. Sato, O. Cunin, K. Toyouchi

    ARCHAEOMETRY   55 ( 6 ) 1034 - 1047  2013.12  [Refereed]

     View Summary

    In this paper, the construction period of the cruciform terraces with columns and the elevated causeways in the Angkor monuments of Cambodia is reconsidered, based on the results of our investigation of magnetic susceptibility and other characteristics of sandstone blocks. From an art-historical point of view, they are generally considered as modifications in the post-Bayon style periodthe period during the reign of Jayavarman VIII (1243-95 ce) or later. However, from a lithological point of view, the average magnetic susceptibilities of the sandstone blocks in the cruciform terraces with columns and the elevated causeways are consistent with the rest of the monument. In addition, the characteristics of the sandstone blocks in the cruciform terraces, such as their shape, the orientation of the bedding plane and the stacking method, suggest that they were constructed in the same period as the rest of the monument.


  • 超臨界条件下でのFeWO4およびMgWO4と2M塩化物水溶液間における2価金属イオンの同時分配実験

    宮崎直樹, 内田悦生

    資源地質   63 ( 3 ) 133 - 142  2013.11

  • Consideration of the Construction Period of the Khmer Temples along the East Royal Road to Preah Khan of Kompong Svay andthe Provenance of Sandstone Blocks Based on Their Magneticthe Provenance of Sandstone Blocks Based on Their Magnetic Susceptibility.

    E. Uchida, I. Shimoda, M. Shimoda

    Archaeological Discovery   1 ( 2 ) 37 - 48  2013.10


  • Quarries and transportation routes of Angkor monument sandstone blocks

    Etsuo Uchida, Ichita Shimoda

    Journal of Archaeological Science   40 ( 2 ) 1158 - 1164  2013

     View Summary

    Sandstone blocks are the main construction materials used in the Angkor monuments in Cambodia. However, a thorough study of the quarries has not yet been carried out. We conducted a field investigation of sandstone quarries from the Angkor period at the southeastern foot of Mt. Kulen, which is approximately 35 km northeast of the Angkor monuments. As a result, we discovered more than 50 sandstone quarries. On the basis of the measurements of magnetic susceptibilities and thicknesses (step heights), we found that they were quarried at different times. These four quarrying areas were identified as the quarries D to G inferred by Uchida et al. (2007). In addition we investigated a canal that was identified on satellite images, connecting quarry sites at the foot of Mt. Kulen to the Angkor monuments. The field investigation suggests a high probability that the canal was used for the transportation of sandstone blocks from Mt. Kulen. © 2012 Elsevier Ltd.


  • NAA and XRF analyses and magnetic susceptibility measurement of Mesopotamian cuneiform tablets.

    J.H. Sterba, E. Uchida, M. Bichler, T. Sasaki, C. Watanabe

    Sienze dell'Antichita   17   409 - 426  2012.09

  • Non-destructive analyses applied to Mesopotamian clay tablets.

    E. Uchida, T. Sasaki, C. Watanabe

    Scienze dell'Antichita   17   394 - 401  2012.09


    E. Uchida, Y. Takubo, K. Toyouchi, J. Miyata

    ARCHAEOMETRY   54 ( 3 ) 549 - 564  2012.06  [Refereed]

     View Summary

    In the cruciform gallery of Angkor Wat in Cambodia, red, orange, white and black pigments were widely painted on the surfaces of pillars, walls and friezes. The application sequence of the pigments is different from area to area. The following substances were confirmed from the pigments: hematite (laterite), minium, calcium oxalate hydrates (whewellite and weddellite), PbCl compounds (cotunnite, laurionite and blixite), calcium phosphates (whitlockite), gypsum, hydrocerussite, calcite, anglesite, lead dioxide, azurite and carbon black. The orange pigment (minium) underlies the red pigment (hematite). The former may have been applied at the time of the foundation (the Angkor Wat style period), and the latter in the Bayon style period or later, but mainly before the early 17th century of the current era.


  • Petrogenesis and Solidification Depth of the Jurassic Daebo and Cretaceous Bulguksa Granitic Rocks in South Korea

    Etsuo Uchida, Seon-Gyu Choi, Daisuke Baba, Yusuke Wakisaka

    RESOURCE GEOLOGY   62 ( 3 ) 281 - 295  2012  [Refereed]

     View Summary

    We investigated the Jurassic Daebo and Cretaceous Bulguksa granitic rocks in South Korea. The former are distributed mainly in the Gyeonggi and Yeongnam massifs and the latter are present in the Gyeongsan basin and Ogcheon belt. The Daebo granitic rocks generally are of ilmenite series and I to S type. These rocks are associated with AuAg hydrothermal deposits, whereas the Bulguksa granitic rocks are of magnetite series and I type, and are associated with PbZn, Cu and MoW hydrothermal deposits, as well as AuAg hydrothermal deposits. The Daebo granitic rocks show adakitic signatures in their chemical compositions. They are considered to have been derived from partial melting of the thick lower continental crust. Conversely, the Bulguksa granitic rocks in the Gyeongsan basin are non-adakitic and are considered to have been derived from partial melting of a mantle wedge. Magmas of the Daebo granitic rocks formed at relatively shallow levels, but solidified at deep levels compared with those of the Bulguksa granitic rocks. The Bulguksa granitic rocks in the central to western Ogcheon belt are considered to have been formed by fractionation of magmas derived from partial melting of continental crust. The total Al contents of biotite and hornblende in the granitic rocks increased, with the Bulguksa granitic rocks in the Gyeongsan basin < the Bulguksa granitic rocks in the Ogcheon belt and Gyeonggi and Yeongnam massifs and the Daebo granitic rocks in the Ogcheon belt < the Daebo granitic rocks in the Gyeonggi and Yeongnam massifs. This order corresponds to an increase in solidification depth.


  • Study on the deterioration of sandstone material

    Report on the Conservation and Restoration Work of the Northern Library inside the Outermost Enclosure of Angkor Wat     132 - 189  2010.12

  • The Angkor monuments. - Stones and their deterioration -

    E. Uchida

    Proceedings of the 3rd Regional Conference on Geological Engineering Research in ASEAN     1 - 8  2010.11

  • Provenance of the sandstone used ion the construction of the Khmer monuments in Thailand

    E. Uchida, K. Ito, N . Shimizu

      52 ( 4 ) 550 - 574  2010.07

  • Annual change of the moisture content in sandstone in the Inner Gallery of Bayon in the Angkor monuments.

    E. Uchida, I. Shimoda, Y. Talkubo, K. Toyouchi

    Annual Technical Report on the Survey of Angkor Monument     155 - 173  2009.11

  • The sandstone used in local city monuments of the Khmer Empire, with regard to Banteay Chmar, Beng Mealea, Koh Ker and Preah Khan of Kompong Svay (Preliminary report)

    E. Uchida, Y. Takubo, K. Toyouchi

    Annual Technical Report on the Survey of ANgkor Monument     174 - 183  2009.11

  • Surface water absorption test for the sandstones in the Angkor monuments.

    E. Uchida, Y. Takubo, K. Toyouchi

    Annual Technical Report on the Survey of Angkor Monument     186 - 195  2008.11


    E. Uchida, O. Cunin, I. Shimoda, Y. Takubo, T. Nakagawa

    RADIOCARBON   50 ( 3 ) 437 - 445  2008  [Refereed]

     View Summary

    In the Angkor monuments of Cambodia, pieces of wood remain (as head frames of doorways, crossbeams, ceiling boards, etc.) in the following 8 monuments: Bakong, Lolei, Baksei Chainkrong, North Khleang, Angkor Wat, Banteay Kdei, Bayou, and Gates of Angkor Thom. Accelerator mass spectrometry (AMS) radiocarbon dating carried Out on 15 wood samples collected from the above 8 monuments revealed that most of the wood samples are original, except for the head frame of a doorway in Baksei Chamkrong, the ceiling boards in the northwest tower. and a crossbeam with pivot hole in the southwest lower of the Inner Gallery of Angkor Wat. The (14)C age for the head frame of a doorway in the inner wall under the central tower of North Khleang supports the hypothesis that the inner walls are additions from a later period.

  • 超臨界条件下における滑石および緑泥石と2M塩化物水溶液間における2価金属イオンの同時分配実験

    内田悦生, 丸尾晃一

    岩石鉱物科学   36   101 - 110  2007.09

  • アンコール遺跡の石材と非破壊調査


    物理探査   60 ( 3 ) 223 - 234  2007.06

  • Relationship between solidification depth of granitic rocks and formation of hydrothermal ore deposits

    Etsuo Uchida, Sho Endo, Mitsutoshi Makino

    RESOURCE GEOLOGY   57 ( 1 ) 47 - 56  2007  [Refereed]

     View Summary

    Chemical analysis of biotite in representative granitic rocks in Japan shows that the total Al (Al-T) content changes with the metal type of the accompanying hydrothermal ore deposits and increases in the following order: Pb-Zn and Mo deposits < Cu-Fe and Sn deposits < W deposits < non-mineralized granitic rocks. The Al-T content of biotite in granitic rocks may be a useful indicator for distinguishing between mineralized and non-mineralized granitic rocks. A good positive correlation is seen between the Al-T content of biotite and the solidification pressure of the granitic rocks estimated by sphalerite and hornblende geobarometers and the mineral assemblages of the surrounding rocks. These facts suggest that the Al-T content of biotite can be used to estimate the solidification pressure (P) of the granitic rocks. The following empirical equation was obtained:
    P (kb) = 3.03 x Al-T - 6.53 (+/- 0.33)
    where Al-T designates the total Al content in biotite on the basis O = 22. According to the obtained biotite geobarometer, it is estimated that Pb-Zn and Mo deposits were formed at pressures below 1 kb, Cu-Fe and Sn deposits at 1-2 kb, W deposits at 2-3 kb and non-mineralized granitic rocks were solidified at pressures above 3 kb.


  • Consideration on the construction process and the sandstone quarries during the Angkor period based on the magnetic susceptibility

    E. Uchida, O. Cunin, C. Suda, A. Ueno, T. Nakagawa

    Journal of Archaeological Science   34 ( 6 ) 924 - 935  2007

     View Summary

    Detailed magnetic susceptibility measurement was conducted on the sandstones used for the Angkor monuments constructed in the period spanning the Preah Ko and Angkor Wat styles, and the construction process of the buildings and quarries of the sandstones was considered. Combined with the previous study on the sandstones of the Bayon style [Uchida, E., Cunin, O., Shimoda, I., Suda, C., Nakagawa, T., 2003. The construction process of the Angkor monuments elucidated by the magnetic susceptibility of sandstone, Archaeometry 45, 221-232], the magnetic susceptibility measurement revealed that there were 7 sandstone quarries corresponding to Stages I, II, III, IVa, V, VII and VIIIb during the Angkor period. The sandstones used for the monuments belonging to Stage I show average magnetic susceptibility values ranging from 1.1 to 2.3 × 10-3 SI units. In the Bakheng style period (Stage II), the average magnetic susceptibility of the supplied sandstones decreased gradually from around 10 to 1 × 10-3 SI units over time. The magnetic susceptibility range of the sandstones used for the monuments of Stage III was from 2.3 to 3.0 × 10-3 SI units. In the early Angkor Wat style period (IVb), the average magnetic susceptibility of the supplied sandstones increased over time, reflecting the supply of the sandstones from two different quarries, that is, the quarry corresponding to the Khleang and Baphuon style monuments (Stage IVa), with low average magnetic susceptibilities of 1.1 to 2.4 × 10-3 SI units, and the quarry corresponding to the main Angkor Wat style monuments (Stage V), with high average magnetic susceptibilities ranging from 2.8 to more than 4.3 × 10-3 SI units. The sandstones of Stage VII show low average magnetic susceptibility around 1 × 10-3 SI unit. The sandstones of Stage VId is a mixture of sandstones of Stages V and those of Stage VII. The sandstones with high magnetic susceptibilities are found in the monuments belonging to Stage VIIIb, reflecting the supply from the new sandstone quarry. © 2006 Elsevier Ltd. All rights reserved.


  • Salt weathering of sandstone at the Angkor monuments, Cambodia: identification of the origins of salts using sulfur and strontium isotopes

    Takahiro Hosono, Etsuo Uchida, Chiyuki Suda, Akiyo Ueno, Takeshi Nakagawa

    JOURNAL OF ARCHAEOLOGICAL SCIENCE   33 ( 11 ) 1541 - 1551  2006.11  [Refereed]

     View Summary

    The Angkor monuments in northwestern Cambodia, which are primarily made of sandstone, are suffering from deterioration due to salt weathering. In order to elucidate the sources of the salts and salt weathering process, this paper analyzed bulk chemical compositions and S (sulfur) and Sr (strontium) isotopic ratios for the salts and surrounding environmental materials. At places where bats inhabit the structures, various kinds of sulfate and phosphate salts are formed on the surface of the sandstone. The results of the analysis demonstrate that the S and P (phosphorus) components in the salts are primarily derived from bat guano. Moreover, Ca (calcium), which is the major element in the salts, is suggested to be derived from both bat guano and the sandstone. The isotopic data strongly suggests that bat guano is related to salt weathering. Removal of these animal excrements is essential for future conservation of these monuments. On the other hand, exfoliation of sandstone commonly occurs due to crystallization of calcite (CaCO3) on platform surfaces of pyramid-type monuments. A large amount of Ca in calcite is suggested to be derived from calcite cement of the building sandstone. (c) 2006 Elsevier Ltd. All rights reserved.


  • Petrological investigation in "Study on the conservation method of bas-relief at inner gallery of Bayon"

    E. Uchida

    Annual Technical Report on the Survey of Angkor Monument 2005-2006 of JASA     149 - 157  2006.09

  • 超臨界条件下における金雲母と2M塩化物水溶液間における2価金属イオンの同時分配実験

    内田悦生, 松本公平

    岩石鉱物科学   35   197 - 206  2006.09

  • 石材の特徴および木炭の放射性炭素年代測定に基づくアンコール遺跡プラサート・スープラの建造年代の推定(日本語訳)

    内田悦生, 須田千幸, 上野晃世, 下田一太

    Report on the Conservation and Restoration Work of the Prasat Suor Prat Tower、JSA     121 - 126  2005.09

  • 超臨界条件下におけるヘデン輝石および透閃石と2M塩化物水溶液間にける2価金属イオンの同時分配実験

    内田悦生, 植草淳一, 片岡輔

    岩石鉱物科学   34   233 - 241  2005.06

  • Outline of Petrological Investigation and theme for conservation and restoration

    Etsuo UCHIDA

    The Master Plan for the Conservation & Restoration of the Bayon Complex, JSA     46 - 59  2005.06

  • Estimation of the construction period of Prasat Suor Prat in the Angkor monuments, Cambodia, based on the characteristics of its stone materials and the radioactive carbon age of charcoal fragments

    E. Uchida, C. Suda, A. Ueno, I. Shimoda, T. Nakagawa

    Journal of Archaeological Science   32 ( 9 ) 1339 - 1345  2005

     View Summary

    Prasat Suor Prat in the Angkor monuments, Cambodia, is situated at the east end of the Royal Plaza and consists of 12 towers numbered N1-N6 and S1-S6 that are mainly made of laterite. Sandstone is also used for pediments, door and window frames, and balusters, etc. Until now, it was thought that Prasat Suor Prat was constructed in the Bayon period. However, the characteristics of the stone materials used for the Angkor monuments suggest that Prasat Suor Prat was constructed in the Angkor Wat period. This is supported by the radioactive carbon age obtained for charcoal fragments collected from the soil between the laterite blocks in the N1 tower and also from the stucco on the inner wall of the N2 tower. © 2005 Elsevier Ltd. All rights reserved.


  • 超臨界条件下における閃亜鉛鉱およびザクロ石と2M塩化物水溶液間における2価金属イオンの同時分配実験

    内田悦生, 福間通之, 佐藤文俊, 遠藤彰

    岩石鉱物科学   33   151 - 162  2004

  • SUPCRT98(修正版SUPCRT92)の熱力学的データセットの信頼性

    尾形正岐, 内田悦生

    資源地質   54 ( 1 ) 47 - 60  2004

  • 超臨界条件下におけるスピネル族鉱物(スピネル、磁鉄鉱)と2M塩化物水溶液間における2価金属イオンの同時分配実験

    内田悦生, 高橋千代子, 太田知昌

    岩石鉱物科学   33   1 - 11  2004

  • ギザ地区からダハシュール地区に分布する古代エジプト遺跡の石材に関する2002年度調査報告

    内田悦生, 伊藤公範

    エジプト学研究/早稲田大学古代エジプト学会   別冊第7号   53 - 69  2004.01

  • Petrological Survey 2002

    Annual Report on the Thechnical Survey of Angkor Monument 2003    2003.11

  • SUPCRT98の熱力学的データの信頼性

    尾形正岐, 内田悦生

    資源地質学会   54 ( 1 ) 47 - 60  2003.06

  • アンコール遺跡(カンボジア)における砂岩材の劣化現象


    地質学雑誌   109 ( 6 )  2003.06

  • ギザ地区からダハシュール地区に分布する古代エジプト遺跡の石材に関する調査-2001年度調査報告-

    内田悦生, 須田千幸

    エジプト学研究   別冊6号   61 - 78  2003

  • Contribution of the magnetic susceptibility of the sandstones to the analysis of architectural history of Bayon style monuments

    Cunin a, Uchida, E.

    Annual Report on the Technical Survey of Angkor Monument 2002/JSA     205 - 253  2002.11

  • 古代エジプト遺跡の石材と劣化 -ギザからダハシュール地区にかけて

    岩石の風化に関するシンポジウム    2002.07

  • アンコール遺跡の石材と保存


    Ohm Bulletin/オーム社   38,Summer  2002.07

  • 鉱物-熱水間元素分配におけるZn2+の挙動

    資源地質学会    2002.06

  • Aqueous speciation of lead and tin chlorides in supercritical hydrothermal solutions

    E Uchida, T Sakamori, J Matsunaga

    GEOCHEMICAL JOURNAL   36 ( 1 ) 61 - 72  2002  [Refereed]

     View Summary

    In order to obtain the stepwise formation constants of tri-chloro complexes of Pb2+ and Sn2+, experiments on the effect of NaCl concentration on the ion exchange equilibria in the systems PbS - ZnS - PbCl2 - ZnCl2 - H2O and CaWO4 - SnWO4 - CaCl2 - SnCl2 - H2O were carried out. The experiments were conducted at 500degrees, 600degrees, 700degrees and 800degreesC (800degreesC is only for Sn2+), 1 kbar and also at 600degreesC, 0.5 kbar using 2 m aqueous chloride solutions. In all the experiments, the Sigmam(Pb)/(Sigmam(Pb)+Sigmam(Zn)) ratio of the aqueous chloride solutions in equilibrium with both PbS and ZnS and the Sigmam(Ca)/(Sigmam(Ca)+Sigmam(Sn)) ratio of the aqueous chloride solutions in equilibrium with both CaWO4 and SnWO4 decrease with the increase of NaCl concentration.
    The experimental results were analyzed thermodynamically using the previously published dissociation constants for NaClaq, CaCl2aq and ZnCl3aq-. As a result, the stepwise formation constants (log K) for PbCl3aq- (PbCl2aq + Cl-aq(-) = PbCl3aq-) were obtained to be -0.1 at 500degreesC and 1 kbar, 0.9 at 600degreesC and 1 kbar, 1.4 at 700degreesC and 1 kbar, and 1.3 at 600degreesC and 0.5 kbar. The stepwise formation constants (log K) for SnCl3aq- (SnCl2aq + Cl-aq(-) = SnCl3aq-) were obtained to be 0.5 at 500degreesC and 1 kbar, 1.4 at 600degreesC and 1 kbar, 2.0 at 700degreesC and 1 kbar, 2.6 at 800degreesC and 1 kbar, and 1.9 at 600degreesC and 0.5 kbar.
    The stepwise formation constants (log K) of tri-chloro complexes of Pb2+. Sn2+, Fe2+, Mn2+, Co2+, Ni2+, Zn2+ and Cd2+ vary with sixfold coordinated ionic radius showing a parabola-shaped curve with a maximum between Mn2+ and Cd2+. This may suggest that the best ionic radius for tri-chloro complex exists between Mn2+ and Cd2+.

  • ギザ地区からダハシュール地区に分布する古代エジプト遺跡の石材に関する調査

    内田悦生, 曽我正樹

    エジプト学研究   別冊5号   42 - 67  2002

  • Petrological Survey 2000

    Annual Report on the Technical Survey of Angkor Monument 2001/JSA   p.225-247  2001.12

  • アンコール遺跡における石材劣化 -特にアンコール・ワット北経蔵における砂岩材の劣化パターン

    岩石の風化に関するシンポジウム    2001.07

  • 超臨界条件下における鉛および錫の溶存状態に関する実験

    内田悦生, 坂森徹平

    資源地質学会    2001.06

  • The stone materials and their deterioration in the Angkor monuments, Cambodia

    Symposium of "Role of Geological Science in Conservation of Cultural Heritage" in Kongju National University/The Geological Society of Korea and Korean Society of Economic and Environmental Geology    2001.05

  • 鉱物—熱水間化学反応計算ソフトウェア Super Critical for Windows

    副島淳一郎, 内田悦生

    資源地質   50 ( 2 ) 115 - 123  2001.02

  • 大分磨崖仏の帯磁率および含水率に基づく非破壊劣化評価

    内田悦生, 安藤大介, 前田庸之

    岩石鉱物科学   30   59 - 67  2001

  • Petrological Survey 1999

    Annual Report on the Technical Survey of Angkor Monument 2000/JSA   pp. 221-241  2000.12

  • 超臨界条件下におけるカンラン石と塩化物水溶液間の元素分配に関する実験

    高橋千代子, 内田悦生

    岩石鉱物科学   29   85 - 96  2000.09

  • 超臨界条件下における花崗岩JG-1aと2M Nacl水溶液間の元素分配実験

    資源地質学会    2000.06

  • Petrological Investigation

    Etsuo Uchida

    バイヨン北経蔵修復工事報告書/JSA     66 - 79  2000.03

    Authorship:Lead author

  • 古代エジプトの建造物の石材について—砂漠の岩石調査・研究—


    生きる/安田火災     24 - 27  2000.02

  • 超臨界条件下におけるイルメナイトと塩化物水溶液間の元素分配に関する実験

    内田悦生, 徳田吉範, 坂森徹平

    岩鉱   95 ( 1 ) 12 - 22  2000.01

  • Cation leaching from the basalt JB-1a by 2M NaCl hydrothermal solutions

    E Uchida, K Tsutsui

    RESOURCE GEOLOGY   50 ( 2 ) 93 - 102  2000  [Refereed]

     View Summary

    The basalt JB-1a was reacted with 2M NaCl solutions, and the leaching behavior of the cations Na, K, Ca, Mg, Fe, Mn, Zn and Co was monitored. The experiments were carried out using standard cold-seal pressure vessels in the temperature range from 300 to 800 degrees C under the constant pressure of 1000 bars and also in the pressure range from 500 to 1000 bars at 600 degrees C.
    The concentrations of Fe, Mn, Zn and Co in the hydrothermal solutions increased significantly with increasing temperature and with decreasing pressure. The thermodynamic analysis of the experimental results suggests that this is due to the formation of trichloro-complexes and also partly due to the temperature dependence of ion exchange between augite and aqueous chloride solution. The Na concentration in the aqueous solution decreases with increasing temperature and with decreasing pressure. On the other hand, the behavior of K, Ca and Mg is complex and their concentrations seem to be controlled by the coexisting minerals.
    Judging from the experimental results, it is concluded that the transition elements are effectively leached from the basalt under higher temperatures and lower pressures. This means that higher temperature and lower pressure conditions are preferable for the production of ore-forming hydrothermal solutions.

  • 超臨界条件下におけるカンラン石と塩化物水溶液間の元素分配に関する実験

    高橋千代子, 内田悦生

    岩石鉱物科学   29   85 - 96  2000

  • 鉱物-熱水間化学反応計算ソフトウェアSuper Critical for Windows

    副島淳一郎, 内田悦生

    資源地質   50 ( 2 ) 115 - 123  2000

  • 超臨界条件下におけるイルメナイトと塩化物水溶液間の元素分配に関する実験

    内田悦生, 徳田吉範, 坂森徹平

    岩鉱   95 ( 1 ) 12 - 22  2000

  • Annual Report on the Technical Survey of Angker Monuments 1999(英文及び邦文)

    日本国際協力センター    1999.07

  • Visual Basicによる日本語版SUPCRET92の作成

    資源地質学会    1999.06

  • 石から探るアンコール遺跡


    物理探査学会    1999.06

  • 石造文化財の保存対策のための概要調査2—石造文化財の保存調査報告書

    内田悦生, 安藤大介, 三好正智

    大分県立歴史博物館     78 - 104  1999.03

  • 大分県に分布する磨崖仏の劣化

    岩石の風化に関するシンポジウム    1999.02

  • Deterioration of stone materials in the Angkor monuments, Cambodia

    Uchida, E., Ogawa, Maeda, Nakagawa

    Engineering Geology   55   101 - 112  1999

  • The laterites of the Angkor monuments, Cambodia-The grouping of the monuments on the basis of the laterites

    Uchida, E., Maeda, N., Nakagawa, T., Nakagawa

    Journal of Mineralogy, Petrology and Economic Geology   94 ( 5 ) 162 - 175  1999

  • The stone materials of the Angkor monuments, Cambodia.—The magnetic susceptibility and the orientation of the bedding plane of the sandstone—

    Uchida, E., Ogawa, Y., Takeshi, N., Nakagawa

    Jour. Min. Pet. Econ. Geul.   93 ( 11 ) 411 - 426  1998.11

  • アンコール遺跡の石材—特にラテライトについて

    日本岩石鉱物鉱床学会    1998.10

  • Annual Report on the Technical Survey of Angkor Monument 1998(英文及び邦文)

    日本国際協力センター    1998.07

  • 超臨界条件下における玄武岩—熱水間の元素の分配に関する実験

    資源地質学会    1998.06

  • パーソナル・コンピュータのための鉱物相平衡計算プログラムパッケージ“PEQ”

    内田悦生, 伊沢俊英, 渡辺昌宏

    岩鉱   93 ( 11 ) 43 - 51  1998.04

  • アンコール遺跡の石材とその劣化

    岩石の風化に関するシンポジウム    1998.02

  • パーソナル・コンピュータのための鉱物相平衡計算プログラムパッケージ"PEQ"

    内田悦生, 伊沢俊英, 渡辺昌宏

    岩鉱   93 ( 2 ) 43 - 51  1998

  • Aqueous speciation of zinc chloride in supercritical hydrothermal solutions from 500 to 700 degrees C and 0.5 to 1.0 kb

    Uchida, E., Naito, M., Ueda, S.

    GEOCHEMICAL JOURNAL   32 ( 1 ) 1 - 9  1998  [Refereed]

    Authorship:Lead author

     View Summary

    Aqueous speciation of zinc in 2N chloride solution was determined experimentally at 500 to 700 degrees C and 0.5 to 1.0 kb by monitoring the effect of NaCl on ion exchange equilibria in the system CaTiO3-ZnTiO3-CaCl2-ZnCl2-H2O. The Ca/(Ca + Zn) value of the 2N aqueous chloride solution in equilibrium with both CaTiO3 and ZnTiO3 decreased with the increase of NaCl under all experimental conditions. This is due to the formation of tri-chloro zinc complex. The formation constant of tri-chloro zinc complex was estimated to be 1.1, 2.1 and 2.7 at 500, 600 and 700 degrees C, 1 kb, respectively, and 2.6 at 600 degrees C, 0.5 kb in logarithm. The formation constant of tri-chloro zinc complex increases with increasing temperature and decreasing pressure. This suggests that zinc can be effectively leached from rocks and magmas under higher temperature and lower pressure conditions.

  • The stone materials of the Angkor monuments, Cambodia. -The magnetic susceptibility and the orientation of the bedding plane of the sandstone-

    Uchida, E., Ogawa, Y., Takeshi, N., Nakagawa

    Journal of Mineralogy, Petrology and Economic Geology   93 ( 11 ) 411 - 426  1998

  • Aqueous speciation of cadmium chloride in supercritical hydrothermal solutions at 500 and 600 degrees C under 0.5 and 1 kbar

    E Uchida, R Inoue, K Ogiso

    GEOCHEMICAL JOURNAL   32 ( 5 ) 339 - 344  1998  [Refereed]

     View Summary

    Aqueous speciation of cadmium in 2 M chloride solutions was determined at 500 and 600 degrees C, 1 kbar and 600 degrees C, 0.5 kbar in the system CaTiO3-CdTiO3-CaCl2-CdCl2-NaCl-H2O using the same experimental method as Uchida et al. (1998). Thermodynamic analysis of the experimental results gives 1.3, 2.3 and 2.9 for the logarithm of the stepwise formation constant of tri-chloro cadmium complex at 500 and 600 degrees C, 1 kbar and 600 degrees C, 0.5 kbar, respectively. The formation constant increases with increasing temperature and decreasing pressure.

  • アンコール遺跡の石材—日本国政府アンコール遺跡救済チーム岩石班調査報告

    岩鉱学会    1997.09

  • 超臨界熱水条件下におけるトリクロロカドミウム錯体の生成定数の温度・圧力依存性

    岩鉱学会    1997.09

  • アンコール遺跡の石材と劣化

    地盤工学会誌   45;8  1997.08

  • Annual Report on the Technical Survey of Angkor Monument 1997(英文及び邦文)

    日本国際協力センター    1997.07

  • 黄鉄鉱・白鉄鉱の浮遊性に対する酸化の影響

    資源・素材学会    1997.03

  • Mixing properties of Fe-Mn-Mg olivine solid solution determined experimentally by ion exchange method

    Uchida, E., Kitamura, Y., Imai, N., Imai

    Journal of Mireralogy, Petrology and Economic Geology   92 ( 4 ) 142 - 153  1997

  • アンコール遺跡の石材と劣化

    内田悦生, 小河善則

    地盤工学会誌   45 ( 8 ) 37 - 42  1997

  • アンコール遺跡の石

    国際交流基金アジアセンター    1996.10

  • 超臨界熱水条件下におけるトリクロロ亜鉛錯体の生成定数の温度・圧力依存性

    三鉱学会    1996.09

  • Annual Report on the Technical Survey of Angkor Monument 1996(英文及び邦文)

    日本国際協力センター    1996.08

  • イルメナイト固溶体-塩化物水溶液間イオン交換平衡実験の再解析

    久保知智, 内田悦生, 古川容子, 今井直哉

    鉱物学雑誌   25 ( 3 ) 59 - 67  1996.07

  • 聖ザビエル天主堂(博物館明治村)に用いられている顔料の鉱物学的研究

    宮田順一, 内田悦生

    岩鉱   91 ( 7 ) 283 - 289  1996.07

  • アンコール遺跡を構成する石材とその劣化

    日本地質学会    1996.04

  • 様々な処理条件下における硫化鉄鉱物の浮遊性

    資源・素材学会    1996.03

  • Aqueous speciation of magnesium, strontium, nickel and cobalt chlorides in hydrothermal solutions at 600 degrees C and 1 kbar

    E Uchida, Y Goryozono, M Naito

    GEOCHEMICAL JOURNAL   30 ( 2 ) 99 - 109  1996  [Refereed]

     View Summary

    The effect of NaCl on ion exchange equilibria in the system CaWO4-MeWO(4)-CaCl2-MeCl(2)-H2O (Me: Mg, Sr, Ni and Co) was experimentally monitored at 600 degrees C and 1 kbar. The Ca/(Ca + Me) ratio of the aqueous chloride solution in equilibrium with both CaWO4 and MeWO(4) was constant for Mg and Sr in spite of the addition of NaCl, whereas the ratio decreased significantly for Ni and Co with the increase of NaCl. The experimental results indicate that both Ni2+ and Co2+ do form higher-order chloro-complexes such as NiCl3 aq and CoCl3aq-, whereas both Mg2+ and Sr2+ may not. The thermodynamic analysis of the experimental results gives 1.5 and 2.1 in logarithm units for the formation constants for NiCl3 aq and CoCl3aq- respectively. By combining the results of Uchida et al. (1995), MeCl(2aq2aq) tends to forms MeCl(3 aq) in the order of SrCl2aq CaCl2aq = MgCl2aq much less than NiCl2aq < FeCl2aq < CoCl2aq < MnCl2aq at 600 degrees C and 1 kbar. Based on ligand field theory, the above order may suggest that the transition metal cations exist as tetrahedral chloro-complexes with low-spin state in the supercritical hydrothermal solutions.

  • Experimental study on ion exchange of Ca2+, Fe2+ and Mn2+ between garnet solid solution and 2N aqueous chloride solution at 600℃ and lkb.

    Uchida, E., Gima, M., Imai, N., Imai

    Journal of Mireralogy, Petrology and Econonie Geology   91 ( 8 ) 305 - 308  1996

  • 聖ザビエル天主堂聖画(博物館明治村)に用いられている顔料の鉱物学的研究

    宮田順一, 内田悦生

    岩鉱   91 ( 7 ) 283 - 289  1996

  • イルメナイト固溶体-塩化物水溶液間イオン交換平衡実験の再解析

    内田悦生, 山上順民

    鉱物学雑誌   25 ( 3 ) 83 - 87  1996

  • 日本国政府アンコール遺跡救済チーム報告2岩石班

    絲綢之路シルクロード/文化財保護振興財団    1996.01

  • 「アンコール遺跡はどのように修復するか」日本国政府アンコール遺跡救済チーム調査研究報告


  • 超臨界熱水溶液中における亜鉛の溶存状態に関する実験

    三鉱学会    1995.10

  • 「アンコール遺跡はどのように修復するか」日本国政府アンコール遺跡救済チーム活動報告


  • Annual Report on the Technical Survey of Angkor Monument 1995(邦文及び英文)

    日本国際協力センター    1995.07

  • 600℃,1kbにおける2N塩化物水溶液中のマグネシウム,ストロンチウム,ニッケル,コバルトの溶存形態

    資源地質学会    1995.06

  • アンコール遺跡を構成する石材とその劣化に関する岩石学的研究-予報

    日本地質学会    1995.04



    GEOCHEMICAL JOURNAL   29 ( 3 ) 175 - 188  1995  [Refereed]

     View Summary

    Aqueous speciation of iron and manganese chlorides in supercritical hydrothermal solutions was determined by monitoring the effects of NaCl and KCl on the Ca/(Ca + Fe) and Ca/(Ca + Mn) ratios of aqueous chloride solutions in equilibrium with scheelite and ferberite and with scheelite and huebnerite, respectively. The experiments were carried out under supercritical conditions of 400 and 600 degrees C, and 1 kbar. The ratios decrease significantly with increasing NaCl and KCl concentrations at both 400 degrees C and 600 degrees C. This is attributable to the formation of higher-order aqueous chloride complexes of Fe and Mn, presumably FeCl3aq- and MnCl3aq-. Based on the thermodynamic analysis of the experimental results using published dissociation constants for NaClaq, KClaq and CaCl2aq, logarithms of the formation constants for FeCl3aq- were obtained to be 0.2(NaCl) and 1.2(KCl) for 400 degrees C, and 1.9(NaCl) and 1.9(KCl) for 600 degrees C, and those for MnCl3aq- to be 0.4(NaCl) and 1.1(KCl) for 400 degrees C and 2.3(NaCl) and 2.3(KCl) for 600 degrees C. This means that the supposition of m(MeCl(2aq)) = Sigma m(Me) for supercritical hydrothermal solutions is invalid.




     View Summary

    The excess Gibbs energy of mixing for a regular solution can be derived systematically by defining the interaction energy for particle groups composed of closest neighbors at equivalent site. The internal energy of a system is regarded as the sum of the interaction energy for particle groups and the excess function is derived from the sum of the interaction energy change caused by the formations of particle groups.
    In the present paper, we have derived the excess Gibbs energy of mixing for ternary and quaternary regular solutions with a closest packing. For a ternary regular solution, the molar excess Gibbs energy of mixing is given as follows, (G) over bar(ex) = X(A)X(B)(X(A)W(AAB)+X(B)W(ABB))+X(B)X(C)(X(B)W(BBC)+X(C)W(BCC))+X(C)X(A)(X(C)W(CCA)+X(A)W(CAA)+2X(A)X(B)X(C)W(ABC), where X(i) is a mole fraction of the component i and W-ijk is an interaction parameter of [ijk] triplet. The following expressions for n-component systems are derived by the similar method by supposing interaction energy among r particles. Some previously proposed models can be derived from our model.
    n=2, r=2: (G) over bar(ex)=X(A)X(B)W(AB) (symmetric binary regular solution model) n=2, r=3:(G) over bar(ex)=X(A)X(B)(X(A)W(AAB)+X(B)W(ABB) (asymmetric binary regular solution model) n=3, r=2:(G) over bar(ex)=X(A)X(B)W(AB)+X(B)X(C)W(BC)+X(C)X(A)W(CA) (symmetric ternary regular solution model) n=3, r=3: (G) over bar(ex) = X(A)X(B)(X(A)W(AAB)+X(B)W(ABB))+X(B)X(C)(X(B)W(BBC)+X(C)W(BCC)) +X(C)X(A)(X(C)W(CCA)+X(A)W(CAA))+2X(A)X(B)X(C)W(ABC) (new ternary model: stated above) n=4, r=4: (G) over bar(ex)=X(A)(3)X(B)W(AAB)+X(B)(3)X(A)W(BBBA)+X(A)(3)X(C)W(AAAC)+X(C)(3)X(A)W(CCCA) +X(A)(3)X(D)W(AAAD)+X(D)(3)X(A)W(DDDA)+X(B)(3)X(C)W(BBBC)+X(C)(3)X(B)W(CCCB) +X(B)(3)X(D)W(BBBD)+X(D)(3)X(B)W(DDDB)+X(C)(3)X(D)W(CCCD)+X(D)(3)X(C)W(DDDC) +3/2X(A)(2)X(B)(2)W(AABB)+3/2X(A)(2)X(C)(2)W(AACC)+3/2X(A)(2)X(D)(2)W(AADD) +3/2X(B)(2)X(C)(2)W(BBCC)+3/2X(B)(2)X(D)(2)W(BBDD)+3/2X(C)(2)X(D)(2)W(CCDD) +3X(A)(2)X(B)X(C)W(AABC)+3X(A)(2)X(B)X(D)W(AABD)+3X(A)(2)X(C)X(D)W-AACD +3X(B)(2)X(A)X(C)W(BBAC)+3X(B)(2)X(A)X(D)W(BBAD)+3X(B)(2)X(C)X(D)W(BBCD) +3X(C)(2)X(A)X(B)W(CCAB)+3X(C)(2)X(A)X(D)W(CCAD)+3X(C)(2)X(B)X(D)W(CCBD) +3X(D)(2)X(A)X(B)W(DDAB)+3X(D)(2)X(A)X(C)W(DDAC)+3X(D)(2)X(B)X(C)W-DDBC +6X(A)X(B)X(C)X(D)W(ABCD).

  • 600℃,1kbにおけるスピネル族鉱物と塩化物水溶液間におけるMg2+,Fe2+,Mn2+イオンの分配実験

    宮本陽子, 内田悦生

    岩鉱   89 ( 5 ) 177 - 188  1994

  • イオン交換平衡実験データから推定されるスカルン流体中の陽イオン濃度比


    資源地質   43 ( 4 ) 301 - 310  1993

  • イルメナイト固溶体と(Fe,Mn,Mg)Cl2水溶液間におけるイオン交換平衡実験

    久保知裕, 内田悦生, 古川容子, 今井直哉

    鉱物学雑誌   21 ( 2 ) 59 - 67  1992.05

  • 栃木県葛生地域の鍋山炭酸塩岩層中に産する含ブルーサイト白色岩とその生成に関与した玄武岩脈について

    中島裕, 内田悦生, 今井直哉, 今井浩人, 大野仁

    岩鉱   87 ( 11 ) 445 - 459  1992



    MINERALIUM DEPOSITA   27 ( 1 ) 58 - 65  1992.01  [Refereed]

     View Summary

    The Taebaek Pb-Zn(-Ag) deposit of the Yeonhwa I mine, Republic of Korea, occurs in a broadly folded and reverse-faulted terrain of Paleozoic sedimentary rocks: the Taebaeksan basin. The orebodies consist of several thin tabular orebodies of hydrothermal replacement type where they are hosted by carbonate rocks. The Pb-Zn(-Ag) mineralization can be divided into four distinct stages based upon the mode of occurrence of ore minerals, ore textural relationships and their composition. Based on temperatures inferred from arsenopyrite compositions by means of electron microprobe and fluid inclusions, the estimated temperatures for the stages I, II, III and IV reach 330 to 350-degrees-C, 270 to 340-degrees-C, 230 to 250-degrees-C, and < 220-degrees-C, respectively. The sulphur activity (atm) of ore formation at the Taebaek deposit was estimated for each stage as 10(-11) to 10(-11.5), 10(-9.5) to 10(-13), 10(-13.5) to 10(-15), and < 10(-15), respectively. Even though application of sphalerite geobarometry is problematic because of the absence of good mineral assemblages, sphalerite coexisting with pyrite but not with pyrrhotite was used to estimate the minimum mineralization pressure (about 1 kbar).

  • Experimental study on phase equilibria in the system CaSiO3-FeSiO3-MnSiO3-(Ca, Fe, Mn)Cl2-H2O by means of ion exchange at 600℃ and 1kbar.

    Ogino, A, Uchida, E, Kakuda, Y, Imai, N

    Mining Geology   42 ( 2 ) 119 - 129  1992

    Authorship:Corresponding author

  • An experimental study on partitioning of Zn, Fe, Mn and Cd between sphalerite and aqueous chloride solution

    Kubo, Nakato, Uchida, E.

    Mining Geology   42 ( 5 ) 301 - 309  1992

  • Experimental study on phase equilibria in the system CaSiO-MnSiO3-(Ca, Mn)Cl2-H2O by means of ion exchange.

    Kakuda, Y., Uchida, E., Imai, N., Imai

    Mining Geology   41 ( 6 ) 339 - 349  1991

  • 三成分系固溶体に対する新たな熱力学モデル

    角田康嗣, 内田悦生, 今井直哉

    鉱物学雑誌   20 ( 1・2 ) 25 - 32  1991.01

  • 地熱系における岩石-熱水間の化学平衡

    内田悦生, 中川隆之, 今井直哉

    早稲田大学理工研究所報告   127   27 - 44  1990.09

  • 岩石-熱水相互作用に関する数値シミュレーション

    中川隆之, 内田悦生, 今井直哉

    早稲田大学理工学研究所報告   129   23 - 33  1990



    GEOCHEMICAL JOURNAL   23 ( 6 ) 339 - 347  1989  [Refereed]

  • Microfacies and diagenesis of the Permian Nabeyama carbonate formation, Kuzuu district, central Japan

    Huber S, Uchida, E, Imai, N, Imai

    Bulletin of Science and Engineering Laboratory, Waseda University   120   1 - 27  1988  [Refereed]

  • 珪酸塩岩の蛍光X線分析 (1)主成分分析

    内田悦生, 高野真, 中村忠張晴, 今井直哉

    早稲田大学理工学研究所報告   117   35 - 41  1987

  • 珪酸塩岩の蛍光X線分析 (2)微量元素の分析

    内田悦生, 渡辺嘉秀, 中村忠晴, 今井直哉

    早稲田大学理工学研究所報告   118   45 - 52  1987

  • Relation between zonal arrangements of skarns and temperatures of formation at the Kamaishi mine, Northeastern Japan.

    Uchida, E.

    Mining Geology   36 ( 3 ) 195 - 208  1986

  • Thermochemical recalculation of equilibrium for the reaction calcite+quartz=wollastonite+CO2

    Ogasawara, Y, Uchida, E, Choi, S.G, Imai, N

    Bulletin of Science and Engineering Research Laboratory, Waseda University   104   1 - 8  1983



    CANADIAN MINERALOGIST   21 ( AUG ) 517 - 528  1983  [Refereed]



    ECONOMIC GEOLOGY   77 ( 4 ) 809 - 822  1982  [Refereed]

  • Thermochemical study on phase equilibria in the system CaO-MgO-SiO2-CO2-H2O

    Ogasawara, Uchida, E., Imai

    Bulletin of Science and Engineering Research Laboratory, Waseda University   98   1 - 24  1982




  • Thermochemical recalculation for thermal dissociation equilibrium of dolomite-Thermochemical studies in the system CaO-MgO-SiO2-CO2-H2O(1)

    Ogasawara, Uchida, E., Imai

    Bulletin of Science and Engineering Research Laboratory, Waseda University   95   15 - 26  1981

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Books and Other Publications

  • 地球・環境・資源 : 地球と人類の共生をめざして (第2版)

    高木, 秀雄, 山崎, 淳司, 円城寺, 守, 小笠原, 義秀, 太田, 亨, 守屋, 和佳, 内田, 悦生, 大河内, 博, 香村, 一夫( Part: Joint editor)

    共立出版  2019.03 ISBN: 9784320047341

  • Preah Vihear - Architectural study on the provincial sites of the Khmer Empire 2

    Takeshi Nakagawa, Akinori Mizoguchi( Part: Contributor)

    Chuo-Koron-Bijutsu Press  2018.10 ISBN: 9784805508589

  • 地球と宇宙の化学事典


    朝倉書店  2012.09 ISBN: 9784254160574

  • 岩石鉱物のための熱力学


    共立出版  2012.09 ISBN: 9784320046764

  • 石が語るアンコール遺跡 岩石学からみた世界遺産


    早稲田大学出版会  2011.03 ISBN: 9784657117045

  • 大谷石、「日本列島ジオサイト 地質百選」


    オーム社  2010.05 ISBN: 9784274208836

  • 地球・環境・資源 地球と人類の共生をめざして

    内田悦生, 高木秀雄編著

    共立出版  2008.09 ISBN: 9784320047037

  • エジプトを護る 「遺跡に使われている石材とその劣化」


    アケト  2006.07 ISBN: 4903000036

  • 鉱物-熱水間元素分配(資源地質環境学-地球史と環境汚染を読む)


    資源地質学会  2003.10

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  • The Best Article Award 2007 (Resource Geology)

    2008.06   The Society of Resource Geology   Relationship Between Solidification Depth of Granitic Rocks and Formation of Hydrothermal Ore Deposits

  • "The research Incentive Award"(The Society of Resource Geology


Research Projects

  • Petrological study on stone materials and their deterioration in the Khmer monuments including the Angkor monuments

    Project Year :


  • Petrological study on stone blocks and their deterioration in the Khmer monuments, Cambodia

    Japan Society for the Promotion of Science  International Joint Research Program

    Project Year :


    Ki-Cheol Shin, Yu Saito

  • Approach to granitic rocks associated with ore deposits by means of field investigations and experiments between minerals and hydrothermal solutions.

    Project Year :


  • A new development of stone deterioration and multidiscipinaly research on conservation in Angkor monument group

    Project Year :


  • Elucidation of formation mechanism of hydrothermal ore deposits accompanied by granitic rocks.

    Project Year :


     View Summary

    Intrusive rocks in Cambodia are separated by the Mea Ping fault. Northeastern intrusive rocks belong to magnetite series and I-type, while southwestern intrusive rocks belong to ilmenite series and I type. The Sr-Nd isotopes indicate that the northeastern intrusive rocks originated from the mantle, while the southwestern intrusive rocks were largely affected by the continental crustal material. Rb-Sr dating indicates that there are four periods of intrusion.Simultaneous ion exchange experiments on cobaltite, arsenopyrite, saffloite and loellingite show that Co and Ni are more likely to enter these minerals. In addition, it was found from the obtained distribution coefficient vs ionic radius diagrams that the gradient of the distribution coefficient vs ionic radius curves are steeper than those of silicate minerals and multiple oxide minerals

  • Study on the Comprehensive Conservation of the Reliefs in the Bayon Temple of the Angkor Complex

    Project Year :


     View Summary

    Research on the reliefs of the Bayon Temple has been carried out not only in conservation sciences, but also in disciplines such as architecture, petrology, microbiology, and metrology. Various preservation materials were administered to sandstone samples of the same composition as the ruins, and a 10-year evaluation test was conducted.We also monitored a test construction at the corridor for 4 years, and succeeded in uniformizing the strength of the Bas-reliefs surface by restoring the strength at the deteriorated parts only. Repair and filling materials for restoration were evaluated, and standard specifications were obtained.The results revealed that a large amount of nitrogen and sulfur components were contained in the wall.Water-soluble components were discovered in the relief surface overgrown with lichens, and finding a proper cleaning method became a challenge.Using laser survey on the relief, we succeeded in quantitatively grasping the aging deterioration of the last years

  • Real image elucidation of the advanced hydraulic city structure of the Royal City of Angkor Thom and vicinity covered by tropical jungle

    Project Year :


     View Summary

    LiDAR data was performed at the Angkor Archaeological Park in Cambodia in April 2012.Using these data a high-resolution red relief image map (RRIM) was created of areas inside and outside the moated royal capital of Angkor Thom. The land around Angkor Thom is extensively covered by tropical jungle. The RRIM provides a new visualization method of localizing, minute topographical changes in regions with large undulations over a wide area.The RRIM expanded the investigation and revealed the existence of many ponds outside the royal capital indicating that a residential community had flourished outside the moat-surrounded capital city.This study will be elucidate the functional aspects of the water channel network and ponds that utilized the gentle gradient of the natural land to overcome the climatic induced environmental changes that are characterized by an extreme divide between the rainy and dry seasons

  • Scientific Technical Research on the Spacial Structure of the Khmer Empire and Ancient Khmer Provincial Principal Monuments

    Project Year :


     View Summary

    We implemented a study for Preah Vihear and Preah Khan in Kompong Svay for about 4 years commencing in 2012 by utilizing a mixed team from architecture and other various fields of study. We were able to achieve significant information from the study.At Preah Kha, a detail measuring survey was implemented. At Preah Vihear, we conducted studies that documented various new discoveries. The architecture unit made detail plan drawing of temple complex and each building and estimated the concept, dimensional plan and process from each measuring data detailed images of the original wooden roof structure from the traces. Petrological unit identified the possibility that part of annex building was older than others by the result of petrological survey such as magnetic susceptibility. Geomorphological unit revealed the relationship between natural and altered terrain, and the archeological unit elucidated the character of the foundation of building and construction method of the mounts

  • Provenance study of cuneiform tablets housed in Sulaimaniyah Museum and geological survey along the Tigris River

    Project Year :


     View Summary

    Clay tablets were illegally excavated on a large scale at many archaeological sites in southern Iraq and smuggled out of the country in the aftermath of the Iraq War. The Iraqi-Kurdish authorities confiscated and saved many of these stolen tablets, which are now housed in the Sulaymaniyah (Slemani) Museum. Our project included chemical, physical and biological analyses of the material used for the tablets in order to provide data concerning their original provenance. Analysis of microfossils contained in the tablets revealed that the clay was sourced not only from river sediments but also from clay pits. Sediment samples taken from the ancient river bed were also analysed for comparison with the tablet clay

  • Petrological approach to elucidation of masonry cultural heritages in Southeast Asia represented by the Angkor monuments.

    Project Year :


     View Summary

    Based on the chemical compositions, magnetic susceptibility, and size and other characteristics of the stone blocks and bricks used in the Angkor monument, the Sambor Prei Kuk monument, the Koh Ker monument and the Preah Vihear monument, we deduced the construction sequence. We found more than 100 quarries of the gray to yellowish brown sandstone used in the Angkor monument, and elucidated the transportation route of the sandstone blocks. In addition, we conducted the investigation of provenance of iron ores which were raw materials of iron used in the construction of the monuments. The surfaces of construction materials have blackened in the Khmer monuments. Most of this discoloring is caused by blue-green algae, but other black areas on the surface of construction materials are frequently observed. A non-destructive investigation revealed that this blackening was caused by manganese oxide precipitates

  • Research for Khmer City Space Image -Revolve Around the Bayon Temple Excavation Survey-

    Project Year :


     View Summary

    On this survey, we conducted elucidation of Khmer city space, especially about its production, technique/technology and distribution, based on the excavation survey within Angkor Thom, mainly in Bayon Temple.Specifically, we conducted following six points: (1) arranging of previous survey records, recording for making archaeological chronology and drawing up the inventory, (2) excavation survey in the Bayon complex and out it, (3) exhaustive survey within Angkor Thom and sampling of archaeological remains from surface of the earth, (4) analysis of sampled natural and metal remains and preservative treatment of the metal them, (5) basic arrangement of purification tools from the pond for preservative treatment in the future, (6) technical knowledge transfer for the Cambodian young archaeologists. Additionally, we supplemented above with comparative surveying the date and material of the artifacts from domestic city sites

  • Ecohistory of salinization and aridification in Iraq

    Project Year :


     View Summary

    Salinization and aridification are serious environmental problems in modern Iraq. In order to understand these problems from the point of view of an interaction between human activities and the natural environment, it is important to consider the ancient historical period when urbanization and rapid population growth occurred. This study endeavored to trace changes in water resources through an analysis of source materials used for clay tablets, which are assumed to have originated in river sediment. We examined microfossils, in particular diatoms, contained in the tablet clay in order to trace the level of salinity in water. In addition, non-destructive chemical analysis was carried out to ensure that the tablet clay was of local origin. The study examined the validity of analyzing this type of clay as a means of tracing environmental changes in antiquity

  • Elucidation of the formation mechanism of hydrothermal deposits based on the element partitioning experiments between mineral/rock and hydrothermal solution and the field investigation.

    Project Year :


     View Summary

    In order to elucidate the factors controlling the metal type disseminated in hydrothermal deposits related to granitic rocks, the investigation was conducted for the Eastern, Central and Western belt granites in Thailand. Observation of rocks under the microscope, magnetic susceptibility measurement, chemical analyses of rocks and constituent minerals were carried out in this study. The most remarkable difference was found in the total Al content in biotite between the Eastern belt granite accompanied with Cu, Pb, Zn and Mo and the Central and Western belt granitic rocks accompanied with Sn and W. This result is concordant with that obtained for the granitic rocks in Japan and South Korea.In addition, element partitioning experiments between mineral and hydrothermal solution were conducted using monazite, xenotime, columbite, tantalite and alabandite. The partitioning behavior of rare earth elements and divalent cations in the hydrothermal process were elucidated experimentally

  • Evaluation of landfill sites as potential urban mines against depletion of rare metal resources

    Project Year :


     View Summary

    We evaluated whether landfill sites can be exploited as a valuable source of various rare metal. This research consists of two kinds of approach. One is to clarify the contents, the chemical form and the enrichment process of metals and temporal changes of mineral composition in landfills. In conclusion, some valuable metals concentrate and exist as sulfide or sulfate or with their minerals in landfills. Another is to develop a nondestructive three-dimensional prospecting system in order to identify metal enriched zones. IP measurements, which focus on chargeability with wastes, are useful.
    These observations indicate that landfill sites may be promising for urban mining as rare metals become scarcer.

  • Application of Surface Analyses to Artistic handicrafts

    Project Year :


  • Studies on the geslogic data for carbonate resources by use of computer

     View Summary

    The results of field and laboratory works, which have been done in the past three years will be summarized as follows.1) The field relation between the Aisawa Formation with beet-like shape and the underlying the Lower Limestones of the Nabeyama Formation is thrust fault in part and unconformity in part.2) The petrochemical studies by XRF and thin section petrography of basaltic rocks of the Izuru Formation represent alkaline basalt of oceanic is laud type. On the other hand, the basaltic dykes, which intruded into the Nabeyama Carbonate Formation belong to volcanic are type.3) At the Tagen mine, the dark gray dolomitic limestones of the upper limestones near the basaltic dyke suffered from bleaching, changing into white rocks with krucite-calcite-dolomite assemblage, however, the presence of brucite has not been recognized under optical microscope. Recently, very fine grains of brucite (2-3mum in size were confirmed by back-scatter electron image.4) Synclinal structure in the Mitsumine area, represented by eynclinal axis with strike of N40゚E and SW-plunging, is not so simple and rather synclinorium

  • Study on Formation Mechanism of Skarn-type Mineral Deposits

     View Summary

    Through three years research, many results were obtained. Only main results are given as follows :1. Mineral Analysis Group : Compositional variations of main skarn minerals such as clinopyroxene and epidote, in a crystal grain, in a hand-specimen, and in an orebody, fall in almost same ranges. Balance between infiltration and diffusion, and local variation as well, of components transported by hydrothermal solutions, cause such compositional variations of skarn minerals.2. Fluid Inclusion Analysis Group : Formation temperatures of skarns have generally very wide ranges such as 500゚ to 200゚C. Salinity of the fluids is very variable. The presence of CO_2 and CH_4 gases is recognizable. In most cases, skarn minerals include many primary inclusions, and hydrogen isotope analysis technique is applicable to those minerals.3. Light Stable Isotope and REE Analysis Group : Oxygen isotope data of Japanese main skarn deposits are accumulated, and it was clarified that most of large-production deposits are formed by hydrothermal solutions of meteoric origin. The Tsumo skarn deposits were formed by the solutions of very complicated origins. REE patterns of skarn minerals are much affected by the physico-chemical conditions of solutions, oxygen fugacities in particular, of the mineral-precipitating solutions.4. Regional Geology Correlation Analysis Group : Minor tungsten mineralizations are observed in many Japanese skarn deposits, overlapping with the Fe-Cu-Zn-Pb mineralizations. They have common characteristics in mineralogy and geology

  • Experiments on the stability of aqueous metal chloro complexes in supercritical hydrothermal solutions

     View Summary

    In order to obtain the information on the aqueous speciation of metals under supercritical hydrothermal solutions, the effect of NaCl on the ion exchange equilibria between minerals and aqueous chloride solution under the coexistence of two phase minerals almost immiscible to each other. In the present study, experiments on the aqueous speciation for Mg^<2+>, Sr^<2->, Fe^<2+>, Mn^<2+>, Co^<2+> and Ni^<2+> were carried out using the CaWO_4-MeWO_4, system and for Zn^<2+> using the CaTiO_3MeTiO_3 system. The experimental conditions are mainly 600゚C and 1kb.As for Mg^<2+> and Sr^<2+>, the Ca/(Ca+Me)ratios of the aqueous chloride solution coexisting with the two solid phases are constant in spite of the increase of NaCl. This indicates that under supercritical hydrothermal solutions, Mg^<2+> and Sr^<2-> dissolve as neutral species, but not as higher-order chloro complexes. On the other hand, for Fe^<2+>, Mn^<2+>, Co^<2+>, Ni^<2+>, and Zn^<2+> the Ca/(Ca+Me) ratios decreased significantly with the increases of NaCl. This can be attributed to the formation of the higher-order chloro complexes of the metals. On the assumption that the metals exist as tri-chloro complexes under the experimental conditions, the formation constants of the tri-chloro complexes are in the order of Mn^<2+>>Co^<2+>>Fe^<2+>>Ni^<2+>. Based on the ligand field theory, it is supposed that the metals form tetrahedral chloro complexes with low-spin state under supercritical hydrothermal solutions.As for Zn^<2+>, the experiments were performed at 500 to 700゚C,1kb and 600゚C,0.5kb. As a result, it is clarified that the formation constant of the tri-chloro complex incerases with the increase of temperature but decreases with the increase of pressure. This suggests that transition metals can be leached effectively from magmas under higher tempearature and lower pressures

  • Study on aqueous speication of metals under supercritical hydrothermal conditions.

     View Summary

    Experiments were performed in order to obtain the information on aqueous speciation of metals in hydrothermal solutions, which is one of the informations indispensable for elucidating the formation mechanism of hydrothermal deposits. For the purpose, the effect of NaCl on ion exchange equilibria between minerals and hydrothermal solutions was examined and the results were analyzed thermodynamically. The experiments were carried out for zinc, cadmium, lead and tin. The experimental conditions were 500 to 700℃ at 1kb and 600℃ at 0.5kb. The chloride concentration of the hydrothermal solutions was fixed to be 2M.Cold seal type pressure vessels were used for the experiments.The experiments revealed that neutral species and/or tri-chloro complexes are dominant aqueous species under the experimental conditions. The formation constant of the tri-chloro complexes of the metals was estimated by the thermodynamic analysis. The plot of the formation constant of the tri-chloro complex including those for iron, manganese, cobalt and nickel previously obtained versus ionic radius shows a parabola-shaped curve with a maximun between manganese and cadmium. However the meaning of the curve is not clear at present.The experimental results show that the metals form tri-chloro complexes at higher temperatures and lower pressures and therefore the solubility increases with increasing temperature and decreasing pressure. In order to confirm whether the obtained results are effective in the more complex system or not, the experiment of cation leaching by 2M NaCl solution was carried out using basalt. The experiments were conducted at 300 to 800℃ under 1kb and at 600℃ under 0.5 to 1.0kb. It was confirmed by the experiments that iron, manganese, cobalt, nickel and zinc tends to be leached preferably from basalt into hydrothermal solutions at higher temperatures and lower pressures

  • Study on the stone materials and their deterioration in the Khmer monuments in Cambodia and Thailand

     View Summary

    The stone materials used for the Khmer monuments, which are widely distributed in Cambodia, Thailand and Laos and were constructed from the 9^<th> to 13^<th> century, and their deterioration were investigated in this study. Sandstone, laterite and brick were used for the monuments, but the focus was put on the sandstone in this study.For the Khmer monuments in Cambodia (generally called the Angkor monuments), the change with times of the characteristics of the sandstone and laterite blocks such as the magnetic susceptibility, shape and orientation of a bedding plane was investigated. Based on the result, construction process of the monuments was elucidated. Especially Prasat Suor Prat, whose construction period has been unknown, was concluded to have been constructed during the Angkor Wat period based on the characteristics of the stone blocks and the radioactive carbon age for the charcoal fragments found from the stucco on the inner wall and the soil put in the interstices of the laterite blocks.The salt weathering is one of the important causes of the deterioration of the sandstone blocks in the Khmer monuments. Two types of salt weathering are observed. One is observed in the inside of the buildings and is related to the crystallization of sulfates and phosphates, and another is observed on the surface of the sandstone blocks constituting the pyramid-type platform and is related to the crystallization of calcium carbonate. The stable isotope analyses of strontium and sulfur were carried out in order to clarify the source materials for the salt weathering. As a result, bat guano for the former and rainwater and sandstone for the latter are considered as the source materials, respectively.For the Khmer monuments in Thailand and Laos, the description of the sandstones used for the monuments and the geological survey around the monuments were carried out in order to know the provenance. As a result, it is elucidated that the sandstones used for the monuments was controlled by the surrounding geology

  • Experiments on element partitioning between rocks, minerals or magmas and hydrothermal solutions under supercritical conditions.

     View Summary

    Information on the element distribution between rocks, minerals and magmas, and hydrothermal solutions is indispensable in understanding of ore-forming and hydrothermal alteration processes. In order to clarify factors controlling element distribution, experiments on simultaneous partitioning of divalent metal ions between minerals and aqueous chloride solutions were carried out for sphalerite, garnet, spinel, magnetite, hedenbergite, tremolite, phlogopite, talc and chlorite. The experiments were performed under 500 to 800℃, lkb, using a standard cold-seal type pressure vessel. As a result, it was clarified that the element distribution is generally controlled by the ion radius, but that Ni, Zn and Co show anomaly in partitioning.In addition, experiments on element partitioning between rocks and aqueous chloride solutions were carried out. Experiments on temperature dependence was conducted for the granodiorite JG-1a in the temperature range of 500 to 800℃, 1kb. Moreover, experiments on pressure dependence was performed for the basalt JB-1a in the pressure range of 0. 3 to 7. 5kb, 600℃. A cold-seal type pressure vessel was used for the experiments in the pressure condition between 0.3 to 2kb, and a piston cylinder type pressure vessel for those in the pressure conditions of 5 and 7. 5kb. These experiments revealed that transition elements were preferentially partitioned into hydrothermal solutions under, higher temperature and lower pressure conditions. This fact suggests that hydrothermal solutions with high potential mineralization will be discharged from magma when it solidifies in shallow conditions

  • Study on stones and their deterioration of the masonry cultural heritages in Southeast Asia

  • Scientific Research on Provincial Ancient Khmer Cities and Temples

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    This study aims to clarify various aspects of provincial cities and temples of the ancient Khmer Empire, which dramatically developed from 9^<th> to 15^<th> century, including geographical relationship with the neighboring countries. Based on detailed recording by field surveys at several archaeological sites build along the "Royal Road" from Angkor, especially Koh Ker and Beng Mealea, from architectural, geomorphological, petrological, art historical and archaeological points of view, we analyze method and process of temple and city design and construction, as well as complete monument inventories with maps and drawings, which will contribute to future conservation planning of these provincial sites


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  • サンボール・プレイ・クック遺跡(カンボジア)のレンガ材表面に析出した石こうに対するSrおよびS同位体分析

    内田悦生, 河西彩, 陳秀テイ, 斎藤有, 申基澈


    Presentation date: 2021.09

    Event date:
  • アンコール遺跡の砂岩材表面に析出した石こうに対するSrおよびS同位体分析

    内田悦生, 河西彩, 中村勇太, 申基澈

    日本文化財科学会第37回大会  (別府大学)  日本文化財科学会

    Presentation date: 2020.09

  • Petrogenesis and tectonic setting in intrusive rocks in Cambodia.

    Etsuo Uchida, Rathborith Cheng, Masato Katayose, Kosei Yarimizu, Ki-Cheol Shin, Sitha Kong, Takanori Nakano

    MAESA Second International Conference on Applied earth Sciences in Myanmar and Neighboring Regions  (ヤンゴン)  The Myanmar Applied Earth Sciences Association

    Presentation date: 2019.11

  • カンボジア ・シェムリアップ アンコール地域における大気汚染と熱帯性豪雨の化学組成に及ぼす影響

    梶川友貴, 大河内博, 中野孝教, 島田幸治郎, 内田悦生, 中川武, 松井敏也, 石塚充雅, 荒井豊明, 宇田川智, PHORSDA Phul, LAY Poty, HANG Peou

    大気環境学会年会  (東京農工大学 府中キャンパス)  大気環境学会

    Presentation date: 2019.09

  • アンコール遺跡に使用されている硬砂岩材

    内田悦生, 杜睿, 中村勇太, 武山達

    (東京芸術大学)  日本文化財科学会

    Presentation date: 2019.06

  • クメール遺跡に使用されている砂岩材の地域変化

    内田悦生, 杜 睿, 中村勇太


    Presentation date: 2018.07

  • カンボジア南西部に産する花崗岩類の化学組成とSr-Nd-Pb同位体組成

    鑓水孝星, 片寄雅仁, CHENG Ratthborith, 申基澈, 内田悦生, 中野孝教


    Presentation date: 2018.06

  • アンコール時代における東王道沿いでの石材の供給

    内田悦生, 櫻井雄一郎, 杜 睿, 山本真吾

    Presentation date: 2017.06

  • カンボジア北東部に産する深成岩類の化学組成とSr-Nd-Pb同位体組成

    片寄雅仁, CHENG Rathborith, 申基澈, 内田悦生, 中野孝教


    Presentation date: 2017.06

  • クメール遺跡から採取された鉄スラグおよび鉄鉱石の化学組成から推定される鉄鉱石の供給源

    内田悦生, 村杉元規, 黒田彩香

    Presentation date: 2016.06

  • 現代メコン川の炭酸系に基づくヒマラヤ水系の河川が炭素 循環に与える影響の考察

    川幡 穂高, 鈴木 淳, 内田悦生


    Presentation date: 2016

  • カンボジア・クメール遺跡の石材表面におけるマンガン酸化物の沈殿

    内田悦生, 渡辺亮太, 大澤里美


    Presentation date: 2015.07

  • カンボジア・クメール遺跡の石材表面におけるマンガン酸化物の沈着

    内田悦生, 渡辺亮太, 大澤里美


    Presentation date: 2014.07

  • 砂岩材の特徴に基づくプレア・ヴィヘア遺跡の建造順序の推定

    内田悦生, 溝口明則, 佐藤広野, 下田一太, 渡辺亮太


    Presentation date: 2014.07

  • 月惑星探査に向けた能動型蛍光X 線分光器AXS の基本特性(Ⅳ)

    内藤 雅之, 長谷部 信行, 草野 広樹, 長岡 央, 大山 裕輝, 桑古 昌輝, 天野 嘉春, 柴村 英道, 久野 治義, T. J. Fagan, 太田 亨, 内田 悦生

    第61 回応用物理学会春季学術講演会 

    Presentation date: 2014

  • 大プレア・カーンに続く王道沿いのクメール寺院の建造年代と石材供給地 − 帯磁率に基づく考察


    Presentation date: 2013.07

  • Quarries and transportation routes of Angkor monument sandstone blocks.

    Etsuo UCHIDA, Ichita SHIMODA

    EurASEAA 14 

    Presentation date: 2012.09

  • アンコール遺跡に使用されている砂岩材の石切り場と運搬経路


    Presentation date: 2012.06

  • 韓国のジュラ紀および白亜紀花崗岩類の全岩および鉱物化学組成における特徴


    Presentation date: 2011.06

  • 砂岩材の帯磁率および特徴に基づくアンコール遺跡の円柱を伴うテラスおよび空中参道の建造時期に関する考察


    Presentation date: 2011.06

  • アンコールワット十字回廊に見られる顔料の研究


    Presentation date: 2010.07

  • 携帯型蛍光X線分析装置および帯磁率計を用いたメソポタミア出土粘土板の非破壊分析


    Presentation date: 2010.06

  • Petrological investigation of the Angkor monuments. - Sandstone-

    Presentation date: 2010.03

  • バイヨン寺院をつくる砂岩材


    Presentation date: 2009.11

  • アンコール遺跡バイヨン内回廊における砂岩材含水率の年変化


    Presentation date: 2009.07

  • クメール帝国地方遺跡に使用されている砂岩材。 バンテアイ・チュマール、ベン・メリア、コー・ケルおよびコンポン・スヴァイのピリア・カーンの場合


    Presentation date: 2009.07

  • Regional variation of the Bulgigsa granitic rocks in the southeastern part of South Korea. With special reference to the total Al content in biotite.

    The Society of Resource Geology 

    Presentation date: 2009.06

  • Tablets studies: Non-destructive analysis of clay tablets by a portable XRF analyzer and a portable magnetic susceptibility meter.

    Interactions between Man and the Enviropnmenta in Mesopotamia. Salinisation in the Context of Environmental Reconstruction during the Second Half of the Third Millenium BC 

    Presentation date: 2008.10

  • JG-1aマグマとNaCl水溶液間における元素分配の圧力依存性


    Presentation date: 2008.06

  • カンボジア、バイヨン寺院南経蔵中央抗における出土金属製品の出土状況と組成分析について


    Presentation date: 2008.06

  • アンコール遺跡(カンボディア)の木材に対する14C年代測定


    Presentation date: 2008.06

  • 砂漠地域における発掘後の考古遺跡の劣化と保存(1)エジプト、アブ・シール南丘陵における結露現象と遺構の劣化


    Presentation date: 2007.08

  • 砂岩材の帯磁率から推定されるアンコール遺跡の建築過程(その2)プラ・コー期からアンコール・ワット期


    Presentation date: 2007.06

  • 携帯型蛍光X線分析装置のアンコール遺跡への応用 − ラテライトの分類とバイヨン寺院内回廊の劣化

    Presentation date: 2007.06

  • インドネシア、中部ジャワ遺跡に使用されている石材の特徴


    Presentation date: 2007.06

  • アンコール遺跡の石材劣化と非破壊調査


    Presentation date: 2007.02

  • タイおよびラオスに分布するクメール遺跡の砂岩材供給源


    Presentation date: 2006.06

  • 遺跡に使われている石材とその劣化


    Presentation date: 2006.01

  • 花崗岩固結深度と熱水性鉱床の生成との関係


    Presentation date: 2005.11

  • カンボジアのアンコール遺跡における砂岩材の塩類風化プロセス:硫黄・ストロンチウム同位体を用いた塩類起源物質の推定


    Presentation date: 2005.07

  • 石材の特徴および木炭の放射性炭素年代測定に基づくアンコール遺跡プラサート・スープラの建造年代の推定


    Presentation date: 2005.07

  • 熱水性鉱床の金属種と関係花崗岩類中の黒雲母のAl含有量との関係


    Presentation date: 2004.06

  • 砂岩材の帯磁率から推定されるアンコール遺跡の建造過程


    Presentation date: 2004.05

  • サンボール・プレイ・クック遺跡における石材劣化


    Presentation date: 2004.05

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Specific Research

  • アンコール遺跡を初めとするクメール遺跡の石材に対する岩石学的研究


     View Summary


  • アンコール遺跡を初めとする東南アジアの石造建造物に対する岩石学的研究


     View Summary

    東王道には27のラテライト造の橋がかかっており、そのラテライトの帯磁率と化学組成に基づき、橋は4つのグループに分かれることが明らかになった。砂岩材と比べてラテライトの供給範囲が狭いことが明らかになるとともに、東道の橋の建造がアンコール・ワット期初期であることが明らかになった。 クレン山裾野のアンコール期の石切り場の全容を明らかにするために石切り場の調査を行ない、新たに21箇所の石切り場を発見した。 ラオスの南部にあるWat Phu寺院などに使用されている砂岩材、石切り場および周辺の砂岩露頭の調査を行なった。これらの砂岩は、カンボジアのアンコール遺跡に使用されている砂岩材と同じ地層から供給されているが、アンコール遺跡の砂岩材と比べて帯磁率が低く、また、Srを初めとして化学組成にも違いが認められた。

  • 花崗岩類に伴われる熱水性金属鉱床の生成機構の解明


     View Summary

    2011年度から継続してタイに分布する花崗岩類の調査を行っており、2015年度は、調査数の少なかった西帯の花崗岩体を対象に調査を行った。今年度の調査対象は、プーケット島の北側に位置するLam Pi、Ban Lam RuおよびRanong地域の花崗岩体である。これに加え、カンボジアの中央部に位置し、古くから鉄の供給地として知られているPhnom Daek岩体の調査を行った。調査では、花崗岩体の記載、帯磁率測定並びに試料採取を行い、採取した試料に対して顕微鏡観察を行うとともに全岩化学組成分析を行った。これらの結果を基に、従来研究を行ってきた日本および韓国の花崗岩類との比較を行った。

  • 超臨界条件下における岩石・鉱物・マグマと熱水間における元素分配実験


     View Summary

    従来は主として6配位サイトを持つ鉱物と塩化物水溶液間における2価陽イオンの同時分配実験を行なったが、本研究では8配位サイトを持つザクロ石(スペサルティン)と6配位および8配位サイトを持つ角閃石(透閃石)および輝石(ヘデン輝石)を用いて2価陽イオンの同時分配実験を行なった。いずれの実験も500~800℃、1kbの条件下で実験を行なった。また、ザクロ石の実験ではNi、Mg、Co、Zn、Fe、Mn、Caイオンの分配を取り扱い、角閃石と輝石の実験ではさらにSrを付け加えた. ザクロ石の場合、Mn付近に極大を持つ、PC-IR曲線が得られ,その勾配は6配位サイトに対する曲線より緩やかであり,8配位サイトが6配位サイトと比べてイオン選択性が緩やかであることを示している。また、温度の増加に伴いPC-IR曲線の勾配は緩やかになり,温度の上昇に伴いイオン選択性が小さくなること示している.なお、Znは,6配位サイトの場合と同様に他の元素とは異なる挙動を示し,サクロ石には濃集しにくいことを示している. 角閃石および輝石の場合には,2価陽イオンの入り得る6配位サイトと8配位サイトに対応する2つのピークが求められた.6配位サイトのピークはNiとMgの間に、8配位サイトのピークはCa近くに位置しており、Mn付近で極小値を示す.6配位サイトに対応するPC-IR曲線は、8配位サイトに対応する曲線と比べて勾配がきつくなっており、6配位サイトは8配位サイトと比べてイオン選択性がきついことを示している.また、温度上昇に伴い,全体的にイオン選択性は小さくなる。これら2鉱物においては、CoとZnが他の2価イオンとは異なる挙動を示し、鉱物中に濃集しにくいことを示している。

  • 超臨界条件下における岩石・鉱物・マグマと熱水間における元素分配実験


     View Summary

     本研究では、地質調査所の日本岩石標準試料である沢入花崗岩JG-1aと塩化物水溶液間における元素分配実験およびザクロ石と塩化物水溶液間における元素分配実験を行った。 前者のJG-1aとの元素分配実験では、反応溶液として2M NaCl水溶液を使用し、300~800℃、1kbの温度・圧力条件下で実験を行った。実験にはテスト・チューブ型高圧反応容器を用いた。実験後、固相と液相を分離し、ICPを用いて化学組成分析を行った。分析可能であった元素は、Na、K、Ca、Mg、MnおよびFeの6元素であった。800℃における分配係数(溶液中の濃度 / 固相中の濃度)は、Mn>Na≒K≒Fe>Ca>Mgであり、溶液中のFe濃度は5000ppmに、Mn濃度は350ppmに達した。熱力学的な解析から、これら遷移金属元素は、液相中では高温になるほどトリクロロ錯体として存在していると推測される。 後者のザクロ石との実験では、固相出発物質としてスペサルティンを使用した。また、反応溶液としては、2N塩化物水溶液を用い、スペサルティンと塩化物水溶液間におけるMn、Fe、Ni、Co、Zn、MgおよびCaの同時分配実験を、500~800℃、1kbの条件下で行った。実験結果をPC-IR(分配係数-6配位イオン半径)図にプロットしたところ、Znを除いて、Mn近傍に頂点を持つ放物線が描けた。Znは液相中に濃集する傾向を示し、これは今までの他の鉱物を用いた実験結果からZnが4配位席を好む性質による。また、得られた放物線の勾配は他の6配位および4配位席を持つ鉱物と比較すると緩やかであり、これはザクロ石における二価イオンの交換席が8配位で大きく、イオン選択性が4配位および6配位の場合と比べて緩やかであることを示している。また、放物線は温度が高くなるにつれて緩やかになり、高温になるにつれてイオン選択性が小さくなることを示している。

  • 超臨界条件下におけるアルカリ長石と塩化物水溶液間のアルカリ元素の分配に関する実験


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     鉱物と超臨界熱水溶液間における多元素同時分配実験として今までに鉱物としてカンラン石、イルメナイト、磁鉄鉱を用いて実験を行なってきたが、その一環として今回はアルカリ長石を用いて同様な実験を行なった。対象とした鉱物はカリ長石であり、溶液には1mol/lのLiCl、NaCl、RbClおよびCsCl水溶液の混合溶液を用いた。カリ長石10~30mgに対して20~40μlの反応溶液を金チューブに封入して、コールド・シール型の高圧反応容器を用いてイオン交換反応を行なった。実験圧力は1kbとし、実験温度は500~800℃と変化させた。実験終了後、固相と液相を分離し、固相はフッ酸と硝酸を用いて溶解した後、液相とともに原子吸光分析装置を用いてアルカリ元素の分析を行なった。また、粉末X線解析装置を用いて生成鉱物の同定を行なった。 実験結果から分配係数を求めた後、イオン半径との関係を示したPC-IR(Partition Coefficient vs. Ionic Radius)図を作成し、考察を行なった。PC-IR曲線はRb付近に極大値を持ち、LiとNaとの間に極小値を持つ曲線を示し、Rbが最も適したイオン半径を持つことが明らかとなった。また、分配係数は温度とともにその対数値が0に近づく傾向を示し、温度の上昇に伴いアルカリイオンに対する選択性が小さくなることを示している。なお、Liイオンの挙動に関しては、今のところ満足な理由を与えることは出来ていない。 今後はこのような傾向がKをNaに置き換えた曹長石においても成り立つかどうか調べるために実験を継続していく予定である。

  • 超臨界条件下における鉱物と熱水間における金属元素の分配実験


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     磁鉄鉱とイルメナイトを用いて超臨界熱水溶液との間におけるFe、Mg、Ni、Co、Zn、Mn2価イオンの分配に関する実験を行った。実験温度は500、600、700および800℃とし、圧力は1kbに固定した。固相出発物質と各種イオンを含有した1mol/lの塩化物水溶液とを金チューブに封入し、標準的なテストチューブ型高圧反応容器を用いて反応させた。反応期間は温度により異なり、5日から7日とした。反応終了後、固相と液相を分離し、固相はエネルギー分散型X線マイクロアナライザーを用いて、液相はICPプラズマ発光分光分析装置を用いて分析した。実験結果を分配係数―イオン半径図(PC-IR図)にプロットし、考察を行った。 実験の結果、磁鉄鉱およびイルメナイトともにCoとFeの中間に頂点を持つ放物線が描けたが、磁鉄鉱の方が急なカーブが描けた。また、温度の上昇に伴い放物線のカーブは緩やかになるとともにその頂点の位置は若干イオン半径の小さくなる方向に移動する傾向が見られた。ただし、NiとZnに関してはこれらの傾向とは異なる挙動を示し、Niに関してはその6配位選択性の、Znに関してはその4配位選択性のためであると解釈される。 また、実験結果に対して溶存種を考慮に入れて熱力学的な考察も行った。計算の結果、実験条件下ではほぼすべての金属イオンが塩化物中性溶存種として存在していることが分かった。また、従来当研究室で行われたこれら2鉱物と塩化物水溶液との間におけるイオン交換平衡実験との整合性を調べたところ両実験結果はほぼ一致していることが分かった。

  • 超臨界条件下における岩石―熱水間の金属元素分配に関する実験


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  • 超臨界熱水溶液中における鉛の溶存状態に関する研究


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    今までに第一遷移金属(Mn, Fe, Co, Ni, Zn)に対して行って来た実験方法と同様な方法を用いて鉛のトリクロロ錯体の生成定数を求めた。実験には、CaTiO3-PbTiO3-CaCl2-PbCl2-NaCl-H2O系とPbS-ZnS-PbCl2-ZnCl2-NaCl-H2O系の2つの系を用いた。常温・常圧におけるPbCl2の溶解度が低いため、PbTiO3およびPbSを出発物質とした場合のみしか実験を行うことが出来なかった。実験は、2Nの塩濃度において行い、溶液のCa/(Ca+Pb)比およびPb/(Pb+Zn)比に及ぼすNaClの影響を調べた。実験条件は、1kbに対しては500、600、700℃とし、0.5kbに対しては600℃とした。 実験終了後、液相と固相を分離し、固相はPbTiO3とCaTiO3またはPbSとZnSの2相が共存しているかどうかX線回折装置を使用して確かめ、液相はICP発光分析装置を用いて陽イオン分析を行った。そして、得られた実験結果を熱力学的に解析し、鉛のトリクロロ錯体の生成定数を求めた。 CaTiO3系の実験では、PbTiO3が1kb、700℃の条件下で不安定であるため実験を行うことが出来なかった。また、PbS-ZnS系に対しては、まだ、0.5kb、600℃における実験が終了していない。しかしながら、全体的には、今までに実験を行った第一遷移金属(Fe, Mn, Co, Ni, Zn)と同様に鉛も高温・低圧条件下でトリクロロ錯体を生成し易いことが明らかとなった。しかしながら、その生成定数は、上記遷移金属に比べて低い。残念ながら、CaTiO3-PbTiO3系とPbS-ZnS系の実験結果の一致は必ずしも良くはなく、この原因を今後明らかにしていく予定である。研究成果の発表(予定)Aqueous Speciation of lead chloride in supercritical hydrothermal solution (Geochemical Journal)

  • 超臨界熱水溶液中におけるアルカリ塩化物の挙動


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     当研究室では、熱水性鉱床の生成に関与した熱水の化学組成を推定するために鉱物と塩化物水溶液間におけるイオン交換平衡実験を行ってきた。 このような実験結果を天然に応用するためには、天然の熱水中に多く溶存するNaClの影響を調べる必要があり、今までに多くの実験を行ってきた。その結果、遷移金属イオンはNaClから解離される塩素イオンと結合し、主として、トリクロロ錯体として存在することが明らかとなってきた。そこで、本研究では他のアルカリ塩化物のイオン交換平衡に及ぼす影響を実験により調べることにより、アルカリ塩化物の超臨界条件下における解離定数を求めた。実験では、LiCl、KCl、RbClおよびCsCl の影響を調べた。実験系としては、これらアルカリ塩化物の影響がよく現れるようにCaTiO3-ZnTiO3-(Ca,Zn)Cl2-H2O系を用いた。実験温度は700℃とし、圧力は1kbとした。また、反応時間は4~6日とした。反応容器としては、テストチューブ型高圧反応容器を用いた。 実験の結果、LiCl、KCl、RbCl、CsClのいずれを用いた場合も、CaTiO3とZnTiO3の2相と共存する塩化物水溶液のCa/(Ca+Zn)比は、アルカリ塩化物濃度の増加に伴い著しく低下した。このことはいずれの塩化物も実験条件下でNaCl同様かなり解離していることを示している。既存のCaCl2aqの解離定数とZnCl3-aqの生成定数を用いて実験結果から熱力学的計算により求められたLiClaq、KClaq、RbClaqおよびCsClaqの700℃、1kbにおける解離定数の対数値は、-4.3、-5.3、-5.2、-5.2であり、NaClaqに対する文献値が-4.9であることを考慮に入れると、イオン半径の小さいイオンほど解離定数が大きいことを示している。この結果が何に起因するかは現在考察中である。

  • 超臨界熱水溶液中における亜鉛クロロ錯体の安定性に関する実験


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    遷移金属の超臨界熱水溶液中における溶存状態を調べるためにCaWO4とMeWO4(Me:遷移金属)の2相と共存する塩化物水溶液のCa/(Ca+Me) 比に及ぼすNaClの影響に関する実験を既にニッケル,コバルト,鉄,マンガンに対して行なって来た。同様の実験を亜鉛に対して行った結果,CaWO4とZnWO4の2相と共存する塩化物水溶液のCa/(Ca+Zn) 比は小さくCaWO4-ZnWO4系はNaClの影響を正確に調べるには適切な系ではないことが分かった。そこで亜鉛の超臨界熱水溶液中における挙動を調べるには他の適切な実験系を探す必要があった。その候補としてCaTiO3-ZnTiO3系を用いて予察的な実験を行ったところ塩化物水溶液のCa/(Ca+Zn) 比は適切な値をとることが分かった。 そこでこの系を用いてCaTiO3とZnTiO3の2相と共存する2N塩化物水溶液との間におけるイオン交換平衡に及ぼすNaClの影響に関する実験を500~700℃,1kbおよび600℃,0.5kbにおいて行った。実験にはテストチューブ型高圧反応容器を用いた。また,出発物質には酸化物の混合物またはこれらを高温・高圧処理して得られた合成物を用いた。実験の結果,いずれの条件下においても上記2相と共存する2N塩化物水溶液のCa/(Ca+Zn) 比は著しく減少し,これはZnCl2aqがNaClaqの解離によって生成されるCl-aqと配位結合しZnCl3-aqを生成することによると考えられる。従来求められているNaClaqとCaCl2aqの解離定数を用いて実験結果を熱力学的に解析した結果,ZnCl3-aqの生成定数の対数値は,1kbでは500,600,700℃の各温度でそれぞれ1.1,2.1,2.7,0.5kbでは600℃において2.6であり,亜鉛のトリクロロ錯体は高温・低圧ほど生成されやすいことが分かった。このことは遷移金属鉱床の生成環境を考える上で重要な知見である。

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Teaching Experience

  • 資源地球化学特論

  • 応用物理化学及び演習

  • 理工学基礎実験ⅡA

  • 環境資源工学実験

  • 地球物質科学

  • 地球科学実験

  • 資源地球科学

  • 地球科学

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Committee Memberships


    資源地質学会  評議員

Social Activities

  • 失われた密林の巨大都市 - カンボジア・アンコールワット

    Eテレ(NHK)  地球ドラマティック 


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  • Ancient Canals Transported Building Blocks to Angkor Wat

    Science  Science 


  • 奇跡の寺院アンコールワット

    Eテレ(NHK)  地球ドラマチック 


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  • The land of Gods: Angkor

    The land of Gods: Angkor 


Media Coverage

  • 光の惑星 地球5千年の旅

    光の惑星 地球5千年の旅  


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    テレビ朝日 キャノンスペシャル エジプトのピラミッドを構成する石材の色に関して実験とともに解説