• Journal of the Mineralogical Society of Korea
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• v.16 no.1
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• pp.49-63
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• 2003

Rare and unusual occurrence of hydrothermal minerals were found in Geode mine area. They are developed in the late stage of hydrothermal alteration of earlier skarns and later by the open-space filling crystallization. The alteration of earlier skarns of clinopyroxene, garnet, and plagioclase formed mainly chlorite or sometimes uncommon hydrothermal minerals of prehnite, illite, and pumpellyite. Open-space filling crystallization characterized by hydrothermal minerals developedin open sapce or good are prehnite, pumpellyite, clinozoisite, illite, and Ca-zeolites of stilbite annstellerite. Mineral phases and paragenesis are examined in detail by microscopy, XRD, SEM, and EPMA. Using the Schreinemaker's method, equibrium reactions among these minerals are establishedand isothemal-isobaric phase diagrams of $\mu$$H_2O$-$\mu$$CO_2$cot are plotted. Hydrothermal minerals such asprehnite, pumpellyite, clinozoisite, illite, and some chlorite were ffrmed under high partial pressure of $CO_2$with relatively low $H_2$O fugacity. Later, stilbite and calcite in association with illite crystallized under relatively both high partial Pressure of $CO_2$and high $H_2$O fugacity.

• Journal of Korean Society of Environmental Engineers
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• v.37 no.8
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• pp.465-471
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• 2015

Adsorption experiments for radionuclides such as $^3H$, $^{90}Sr$ and $^{99}Tc$ were conducted using fractured rock collected in unsaturated zone. The released radionuclide through artificial barrier from the near surface repository can be transported by the flow of rainfall or pore water through fractures in unsaturated zone and reach to groundwater flow. Therefore, it is important to investigate transport behavior (retardation) of radionuclides through fractured rock for the safety assessment and long-term performance of repository. Fractured rock samples were collected and characterized by X-ray microtomography (XMT) analysis, which can be used to develop a more robust unsaturated fracture transport model. When fracture-filling materials are exist, distribution coefficient of $^{90}Sr$ is higher than without fracture-filling materials. In this study, batch sorption distribution coefficient ($K_d$) of radionuclide was determined and used to increase our understanding of radionuclide retardtion through fracture-filling materials.

• Conservation Science in Museum
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• v.20
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• pp.77-92
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• 2018

A stone seated bodhisattva (Sinsu5971) was discovered in Pyeongchang-gun, Gangwon-do in 1974 and was transferred to the Chuncheon National Museum upon its opening in 2002. The statue had damage to wide areas and was thus difficult to restore. This study utilized 3D scanning and 3D printing technologies to identify the overall form of the statue and the degree of damage, which allowed the restoration of lost portions that otherwise could not have been accurately restored to their original shape. Prior to the conservation treatment, the pigments used to decorate the surface were investigated using an optical microscope, and their main components were analyzed with a p-XRF (Potable X-ray Fluorescence Analyzer). The deteriorated lacquered surface was stabilized using animal glue and consolidated with stone strengthener (OH-100). The investigation found that the surface of the statue was made of zeolite that was lacquered and then gilded. As for pigments, white lead was used for the white color and red lead and cinnabar were used for red. The lost portions were redesigned by mirroring the remaining parts with 3D technologies. However, it was difficult to affix the 3D printing outputs to the statue without visible gaps since the damaged parts suffered flection. The portions of the outputs to be connected to the statue were thus modified and supplemented. It was also difficult to collect data on the properties of 3D printing materials due to the lack of previous in-depth study. These obstacles are subjects for further study.

• Journal of the Mineralogical Society of Korea
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• v.15 no.4
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• pp.259-272
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• 2002

This study was tried to interpret the important major factors controlling some physicochemical properties by comparing mineralogical and physicochemical characteristics such as pH, cation exchange capacity, Methylene Blue adsorption amount, swelling, viscosity, strength (compressional and tensile), and surface area etc. Investigated bentonite samples are five Korean samples from Dusan, Naa, Oksan, Dongyang, and Yeonil deposits and two Japanese bentonites from Tsukinuno and Tomioka deposits which were formed under a similar geological environment of the Tertiary basin. Tsukinuno bentonite is only natural Na-type bentonite and the others are all Ca-type bentonites. Most of the properties are not explained by the montmorillonite content only though the most important factor controlling the physicochemical properties is the montmorillonite content. The layer charge of montmorillonite will strongly control cation exchange capacity and Methylene Blue adsorption. Zeolite bearing bentonites show the strong alkaline character and causes the increase of cation exchange capacity, however decrease swelling, viscosity and strengths. Pyrite bearing bentonites decrease green compressional strength and wet tensile strength. The exchangeable interlayer cations control some physicochemical properties. Na-type bentonite than Ca-type shows more strong alkaline character and much more advanced swelling and viscosity. Also the size and thickness of montmorillonite flakes seem to control some physicochemical properties. Bentonite mainly composed of montmorillonite of very thin and large flakes is characterized by the very high surface area, cation exchange capacity, viscosity, swelling, Methylene Blue adsorption, green compressional strength and wet tensile strength. Domestic Dusan bentonite shows the most excellent physicochemical properties, which is due to the high content(84%) and very well crystallinity of montmorillonite.

• Economic and Environmental Geology
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• v.34 no.1
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• pp.13-23
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• 2001

Bentonite layers are intercalated within the basal conglomerates in the Tertiary sedimentary basins of Kampo, Janggi and Pohang, southeastern Korea. Eighteen samples of the bentonites went through X-ray diffraction, scanning electron microscopy, heavy mineral analyses, chemical analyses and oxygen, hydrogen stable isotope analyses to define the mineralogical characters of the bentonites. Heavy minerals such as zircons, apatites, amphiboles and biotites separated from bentonites show clean and euhedral surfaces, which are the characteristic features of volcanic origin. But biotites from the Chunbook Conglomerate are found as altered and heavily broken flakes which implies longer transportation of these bentonites. $TiO_{2}/Al_{2}O_{3} ratios of <2 $\mu$m particle fractions (the Chunbook Conglomerate 0.031; Janggi 0.029; Kampo 0.025) suggest that those are originated from volcanic tuffs. That is, the higher the value is, the more mafic in chemical compositions of the original tuffs. Authigenic montmorillonite and zeolite minerals were observed by SEM, which indicates diagenesis origin of bentonites. But the samples from the Chunbook Conglomerate showed only chaotically packed clay flakes in the matrix of sands or conglomerates, which implies detrital influence, not authigenic origin. The structural formulae of montmorillonite from these basins reflects their environment of formation. Fe (Ⅵ) can show the redox condition of its past environment and much lower $Fe^{2+}(Ⅵ)/Fe^{3+}(Ⅵ)$ ratios in montmorillonite of the Chunbook Conglomerate imply the greater oxidizing influence. Calculated burial depths from oxygen stable isotope data of the samples from the Chunbook Conglomerate generally fall to the range of 929~963 m whereas the real burial depth of this area is only 530~580 m. This could be explained as the bentonites of the Chunbook conglomerate had not been formed in situ. Discriminant analyses with the data from chemical analyses and structural formulae of montmorillonites show that bentonites from three different basins could definitely be distinguished with each other. This result arises from the different chemical compositions of original volcanic ashes and the difference of sedimentary environments.

• Korean Journal of Heritage: History & Science
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• v.37
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• pp.285-307
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• 2004

Synthesize and examine petrological characteristic and geochemical characteristic by weathering formation of rock and progress of weathering laying stress on stone cultural properties of Unjusa temple of Chonnam Hwasun county site in this research. Examine closely weathering element that influence mechanical, chemical, mineralogical and physical weathering of rocks that accomplish stone cultural properties and these do quantification, wish to utilize by a basic knowledge for conservation scientific research of stone cultural properties by these result. Enforced component analysis of rock and mineralogical survey about 18 samples (pyroclastic tuff; 7, ash tuff; 4, granite ; 4, granitic gneiss; 3) all to search petrological characteristic and geochemical characteristic by weathering of Unjusa temple precinct stone cultural properties and recorded deterioration degree about each stone cultural properties observing naked eye. Major rock that constitution Unjusa temple one great geological features has strike of N30-40W and dip of 10-20NE being pyroclastic tuff. This pyroclastic tuff is ranging very extensively laying center on Unjusa temple and stone cultural properties of precinct is modeled by this pyroclastic tuff. Stone cultural propertieses of present Unjusa temple precinct are accomplishing structural imbalance with serious crack, and because weathering of rock with serious biological pollution is gone fairly, rubble break away and weathering and deterioration phenomenon such as fall off of a particle of mineral are appearing extremely. Also, a piece of iron and cement mortar of stone cultural properties everywhere are forming precipitate of reddish brown and light gray being oxidized. About these stone cultural properties, most stone cultural propertieses show SD(severe damage) to MD(moderate damage) as result that record Deterioration degree. X-ray diffraction analysis result samples of each rock are consisted of mineral of quartz, orthoclase,plagioclase, calcite, magnetite etc. Quartz and feldspar alterated extremely in a microscopic analysis, and biotite that show crystalline form of anhedral shows state that become chloritization that is secondary weathering mineral being weathered. Also, see that show iron precipitate of reddish brown to crack zone of tuff everywhere preview rock that weathering is gone deep. Tuffs that accomplish stone cultural properties of study area is illustrated to field of Subalkaline and Peraluminous, $SiO_2$(wt.%) extent of samples pyroclastic tuff 70.08-73.69, ash tuff extent of 70.26-78.42 show. In calculate Chemical Index of Alteration(CIA) and Weathering Potential Index(WPI) about major elements extent of CIA pyroclastic tuff 55.05-60.75, ash tuff 52.10-58.70, granite 49.49-51.06 granitic gneiss shows value of 53.25-67.14 and these have high value gneiss and tuffs. WPI previews that is see as thing which is illustrated being approximated in 0 lines and 0 lines low samples of tuffs and gneiss is receiving esaily weathering process as appear in CIA. As clay mineral of smectite, zeolite that is secondary weathering produce of rock as result that pick powdering of rock and clothing material of stone cultural properties observed by scanning electron micrographs (SEM). And roots of lichen and spore of hyphae that is weathering element are observed together. This rock deep organism being coating to add mechanical weathering process of stone cultural properties do, and is assumed that change the clay mineral is gone fairly in stone cultural properties with these. As the weathering of rocks is under a serious condition, the damage by the natural environment such as rain, wind, trees and the ground is accelerated. As a counter-measure, the first necessary thing is to build the ground environment about protecting water invasion by making the drainage and checking the surrounding environment. The second thing are building hardening and extirpation process that strengthens the rock, dealing biologically by reducing lichens, and sticking crevice part restoration using synthetic resin. Moreover, it is assumed to be desirable to build the protection facility that can block wind, sunlight, and rain which are the cause of the weathering, and that goes well with the surrounding environment.