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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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+.

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.

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.

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.

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.

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.

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).

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).

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

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

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

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

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

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

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

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

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.

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

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

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

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

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

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

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

THIS STUDY AIMED TO ASCERTAIN DETERIORATION PHENOMENON, AS WELL AS TO DEVELOP THE CONSERVATION MATERIAL, SPECIALIZED FOR BAYON TEMPLE. THIS STUDY FOUND OUT THAT ONE OF THE DETERIORATION FACTORS IS RAINWATER BLEEDING FROM THE EARTHEN PLATFORM INSIDE THE REAR OF THE BAS-RELIEF. FOR THIS OUTCOME, AN ENGINEERED COUNTERMEASURE HAD BEEN IMPROVED, IN ADDITION TO THE DEVELOPMENT OF TOUGHENING MATERIALS, WHICH IS BASED ON SILICATE ESTER FOR THE SANDSTONE OF THE BAS-RELIEF

　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。

　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。

　玄武岩とNaCl水溶液間における元素の分配実験を行った。玄武岩としては地質調査所の標準岩石試料JB-1aを用いた。実験では、元素分配の温度、圧力および塩濃度依存性を調べた。玄武岩の粉末60mgとNaCl反応溶液80μlを直径4.4mm、長さ約3.5cmの金チューブに封入し、テストチューブ型高圧反応容器を用いて実験を行った。温度依存性の実験では、圧力１kb、NaCl濃度１mol／lとし、温度は500、600、700、800℃と変化させた。圧力依存性の実験では温度600℃、NaCl濃度１mol／lとし、圧力は0.5、0.75、１kbと変化させた。塩濃度依存性の実験では温度600℃、圧力１kbとし、NaCl濃度は0.5、１、２、３、４mol／lと変化させた。実験終了後、固相と液相を分離し、粉末X線回折装置により生成鉱物を同定し、また、EPMAを用いて生成鉱物の化学組成を決めた。液相中の各イオンの組成はICPにより求めた。固相に関しては、フッ酸と硝酸を用いて溶解した後、ICPにより組成を求めた。実験の結果、遷移金属であるMn、Fe、Co、Znの水溶液中の濃度は塩濃度および温度の上昇または圧力の低下に伴い増加した。これは、実験条件下においてこれら遷移金属が主としてトリクロロ錯体をなして溶存していることで説明される。Mgの変化は遷移金属に比べて小さいが、圧力依存性を除いて遷移金属と反対の傾向を示した。Naは低温、高圧ほど水溶液中に濃集し易い傾向を示した。CaとKは複雑な挙動を示し、生成する鉱物相によって支配されている。

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)

　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。

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。