• The Journal of Engineering Geology
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• v.26 no.1
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• pp.23-32
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• 2016

This study evaluates landslide susceptibility using statistical analysis by SVM (support vector machine) and the illite index of clay minerals extracted from ASTER(advanced spaceborne thermal emission and reflection radiometer) imagery which can be use to create mineralogical mapping. Landslide locations in the study area were identified from aerial photographs and field surveys. A GIS spatial database was compiled containing topographic maps (slope, aspect, curvature, distance to stream, and distance to road), maps of soil properties (thickness, material, topography, and drainage), maps of timber properties (diameter, age, and density), and an ASTER satellite imagery (illite index). The landslide susceptibility map was constructed through factor correlation using SVM to analyze the spatial database. Comparison of area under the curve values showed that using the illite index model provided landslide susceptibility maps that were 76.46% accurate, which compared favorably with 74.09% accuracy achieved without them.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.12 no.5
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• pp.747-754
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• 2001

This paper describes measurement of relative permittivity of illite found in young-dong area. A measurement of relative permittivity of the illite was made using cylindrical cavity resonators with a moveable cap. A concentric dielectric-rod inserted the cylindrical cavity resonator and an exact field representation of non-decaying mode of the resonator are introduced for the measurement of relative permittivity. The exact electromagnetic fields in cylindrical cavity with a concentric dielectric rod is analysed. The relative permittivity of dielectric in the cavity is calculated by analyzing a characteristic equation. The characteristic equation is solved by using the ContourPlot graph of Mathematica. We know that the field representation of non-decaying mode is exact. As a result, the relative permittivity of dielectric materials was 7.820 for a sample with binder and 7.894 for a pure sample.

• Economic and Environmental Geology
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• v.49 no.2
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• pp.97-104
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• 2016

Here we firstly present that a timing of reactivated event of Yangsan fault, the major fault in the southeastern Korean Peninsula, by using combined approaches of the optimized illite-polytype quantification, the K-Ar age-dating, and the recently developed illite-age-analysis (IAA) approach for the fault clays from Sangcheon-ri area of Yangsan main fault line. Two chronological record of brittle fault-activation event at about 41.5~43.5 and 50.7 Ma were determined from 3 fault gouges suggesting a crucial reactivation time-scheme. Furthermore, the regional processes that drive tectonics to form and reactivate the Yangsan fault may be explained from the chronological analysis for additional sites along the Yangsan fault.

• Economic and Environmental Geology
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• v.25 no.1
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• pp.41-50
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• 1992

Mineral assemblages, mineral chemistries and stable isotope compositions of altered rocks of the Ogmae, Seongsan, Haenam and Gusi mines near the Haenam volcanic field in the southwestern part of the Korea peninsula were studied. Characteristic hydrothermal alteration zones in these deposits occurring in the Cretaceous volcanics and volcanogenic sediments, acidic tuff, and rhyolite, were outlined. Genetic environment with particular reference to the spatial and temporal relationships for these deposits were considered. The alteration zones defined by a mineral assemblage in the Ogmae and Seongsan deposits can be classified as alunite, pyrophyllite, kaolinite or dickite, quartz, illite or illite/smectite. Alunite was not developed in the Gusi and Haenam deposits. Boundaries between the adjacent zones are always gradational except for vein-type alunite. Alteration zones are superimposed upon each other in some localities. These deposits formed $71.8{\pm}2.8{\sim}76.6{\pm}2.9$ Ma ago, which is the almost same age of later volcanic rocks $79.4{\pm}1.7{\sim}82.8{\pm}1.2$ Ma, the Haenam Group, corresponding to Campanian. It indicates that hydrothermal alteration of these deposits appeared to be related to felsic volcanism in the area. Consideration of the stability between kaolinite, alunite, pyrite and pyrophyllite, and the geothermometry based on the mineral chemistry of illite and chlorite suggests that the maximum formation temperature for alunite and pyrophyllite can be estimated at about $250^{\circ}C$ and $240{\sim}290^{\circ}C$, respectively. It also suggests that these deposits were formed by acidic sulfate solution with high aqueous silica and potassium activity in a shallow depth environment. Compositional variation of alunite also suggests that the physico-chemical conditions fluctulated considerably during alteration processes, indicating shallow depth environment. The Haenam deposit was formed at a relatively greater depth than the others. The sulfur isotope composition of alunite and pyrite indicates that sulfur probably had a magmatic source, and the oxygen isotope composition for kaolinite indicates that the magmatic hydrothermal solution was diluted by circulating meteoric water.

• Journal of the Mineralogical Society of Korea
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• v.4 no.1
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• pp.32-42
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• 1991

Illite 'crystallinity' and chlorite chemistry are applied to the evaluation of the thermal grade of the Jigunsan Formation. Illite 'crystallinity' value of the formation has the range fom 4.48 to 32.5 in Weaver index (W.I.) and from $0.14{{\Delta}{\circ}}\;2{\Theta}$to $0.03{{\Delta}{\circ}}\;2{\Theta}$in kubler index (K.I). Most of illite 'crystallinity' values in this formation belong to the epizone field (K.I.<$0.21{{\Delta}{\circ}}\;2{\Theta}$). The chemistry and calculated temperature of chlorites from this formation (Fe/(Fe+Mg)=0.45, Tet. Al/Octa. Al=0.84, the calculated temperature=250-270${\circ}C$) are similar to those of epizone chlorites in the literature. The results of this work show that the metamorphic grade of the Jigunsan Formation belongs to the epizone and the formation is believed to have been reached paleotemperatures of at least 300${\circ}C$.

• Korean Journal of Soil Science and Fertilizer
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• v.32 no.4
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• pp.421-428
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• 1999

Potassium (K) released from weathering of biotite in soils has been recognized as one of major K-sources for plant growth. Sand size biotite in a soil-saprolite-parent rock profile developed under temperate climate was studied in terms of morphological, mineralogical, and chemical changes according to depth employing petrographic and electron microscopes. X-ray diffraction, and electron microprobe. Biotite showed discoloring from black to goldish white and loss paleochroism with decreasing depth. Both edge and layer weatherings of biotite showed in this study. Hexagonal holes and cracks on (001) plane of weathered biotite grains were observed and their members increased with increasing weathering degree. Biotite was altered to kaolinite with or without intermidiate products such as hydrobiotite, degraded biotite, and illite. Average chemical composition of weathered biotite changed to that of katolinite with decreasing depth: increasing concentrations of silicon (Si) and aluminum (Al) and decreasing concentrations of potassium (K), iron (Fe), magnesium (Mg), manganese (Mn), and taitanium (Ti).

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.19 no.4
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• pp.459-467
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• 2021

In the majority of countries, the upper limit of buffer temperature in a repository is set to below 100℃ due to the possible illitization. This smectite-to-illite transformation is expected to be detrimental to the swelling functions of the buffer. However, if the upper limit is increased while preventing illitization, the disposal density and cost-effectiveness for the repository will dramatically increase. Thus, understanding the characteristics and creating a database related to the buffer under the elevated temperature conditions is crucial. In this study, a strategy to investigate the bentonite found in Korea under the elevated temperatures from a mineral transformation and radionuclides retardation perspective was proposed. Certain long-term hydrothermal reactions generated the bentonite samples that were utilized for the investigation of their mineral transformation and radionuclide retardation characteristics. The bentonite samples are expected to be studied using in-situ synchrotron-based X-Ray Diffraction (XRD) technique to determine the smectite-to-illite transformation. Simultaneously, the 'high-temperature and high-pressure mineral alteration measurement system' based on the Diamond Anvil Cell (DAC) will control and provide the elevated temperature and pressure conditions during the measurements. The kinetic models, including the Huang and Cuadros model, are expected to predict the time and manner in which the illitization will become detrimental to the performance and safety of the repository. The sorption reactions planned for the bentonite samples to evaluate the effects on retardation will provide the information required to expand the current knowledge of repository optimization.

• Journal of the Mineralogical Society of Korea
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• v.32 no.3
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• pp.173-184
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• 2019

Variations in grain size distribution and clay mineral assemblage are closely related to the sedimentary facies that reflect depositional conditions during the glacial and interglacial periods. Gravity cores BS17-GC15 and BS17-GC04 were collected from the continental shelf and rise in the eastern Bellingshausen Sea during a cruise of the ANA07D Cruise Expedition by the Korea Polar Research Institute in 2017. Core sediments in BS17-GC15 consisted of subglacial diamicton, gravelly muddy sand, and bioturbated diatom-bearing mud from the bottom to the top sediments. Core sediments in BS17-GC04 comprised silty mud with turbidites, brownish structureless mud, laminated mud, and brownish silty bioturbated diatom-bearing mud from the bottom to the top sediments. The clay mineral assemblages in the two core sediments mainly consisted of smectite, chlorite, illite, and kaolinite. The clay mineral contents in core GC15 showed a variation in illite from 28.4 % to 44.5 % in down-core changes. Smectite contents varied from 31.1 % in the glacial period to 20 % in the deglacial period and 25.1 % in the interglacial period. Chlorite and kaolinite contents decreased from 40.5 % in the glacial period to 30.3 % in the interglacial period. The high contents of illite and chlorite indicated a terrigenous detritus supply from the bedrocks of the Antarctic Peninsula. Core GC04 from the continental rise showed a decrease in the average smectite content from 47.2 % in the glacial period to 20.6 % in the interglacial period, while the illite contents increased from the 21.3 % to 43.2 % from the glacial to the interglacial period. The high smectite contents in core GC04 during the glacial period may be supplied from Peter I Island, which has a known smectite-rich sediment contributed by Antarctic Circumpolar Currents. Conversely, the decrease in smectite and increase in chlorite and illite contents during the interglacial period was likely caused by a higher supply of chlorite- and illite-enriched sediment from the eastern Bellingshausen Sea shelf by the southwestward flowing contour current.

• Journal of the Korean Recycled Construction Resources Institute
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• v.5 no.2
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• pp.185-191
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• 2017

The objective of this paper is to investigate the effect of waste refractory powder(WRP) and desulfurization gypsum(FGD) as activators on the flow properties and the strength development of high volume blast furnace slag mortar incorporating illite(BSM) having adsorption and deodorization. To fabricate the BSMs with 60% of W/B, blast furnace slag are incorporated with 45% and 65%, respectively. WRP and FGD are substituted from 5 to 10%. Test results indicate that the flow is decreased with increase of WRP and FGD, while increase of WRP and FGD enhance the compressive strength due to accelerated reaction of blast furnace slag, The use of illite results in a decrease of compressive strength. pH has increasing tendency until 7days, while it has reduction. In this paper, optimal dosages of WRP and FGD are believed to be around 5% each.

• The Journal of Engineering Geology
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• v.24 no.3
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• pp.411-421
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• 2014

The purpose of this study is to analyze the key factors that contribute to landslide causes through swelling clay minerals and terrain analysis in landslide sites taken place of in Yongin city, Gyeonggi-do, 2011. The study was conducted based on field survey by XRD (X-ray Diffraction), XRF (X-ray fluorescence), spectroscopic analysis on soil samples obtained from landslide sites and ASTER satellite image. Illite shows absorption features; $Fe^{2+}$ and $Fe^{3+}$ at 0.9 and $1.0{\mu}m$, broad water absorption features near 1.4 and $1.9{\mu}m$, and additional Al-hydroxyl features at 2.2, 2.3 and $2.4{\mu}m$, respectively. These absorption features are consistent with the bands 5, 6, and 7 of ASTER (Advanced Spaceborne Thermal Emission and Reflection Radiometer) satellite image. Illite image was extracted using band math of $SWIR_{Illite}$. From these results, we confirmed the applicability of ASTER satellite image using identification of swelling clay minerals to landslide study.