• 한국전자현미경학회:학술대회논문집
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• 1993.06a
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• pp.24-24
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• 1993

• Economic and Environmental Geology
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• v.31 no.6
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• pp.485-498
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• 1998

The water-rock interaction and anthropogenic contamination affecting to geochemical composition of shallow and deep groundwaters were investigated in the agricultural area of Myunggok-ri, Kongju. The shallow groundwater is classified into the chemical types of $Ca-HCO_3$ and $Ca-Cl(SO_4)$ and shows weak acid having an average pH 6.2. Deep groundwater shows the uncontaminated composition of the chemical types of $Na-HCO_3$ and Na $(Ca)-HCO_3$ with pH of 8.4~8.8. The grouping approach of chemical data of waters shows the distinguished trend between water composition influenced anthrophogenic input and water composition mainly determined by natural process such as water-rock interaction. The main anthropogenic inputs affecting chemical composition of shallow groundwater are the contaminants such as $K^+$, $NO_3{^-}$, $Cl^-$ having average values of 4.4 mg/l, 22 mg/l, 13.7 mg/l, respectively. The contaminants were probably derived from fertilizer, sweage, septic tank, and stable, etc. The hydrogen and oxygen isotopic compositions indicate that five deep groundwaters were recharged from different altitudes, and that shallow and deep groundwaters were originated from meteoric water. Tritium contents of waters suggest that deep groundwater was recharged before or just after 1950s, and that shallow groundwater is much younger than deep groundwater. The results of this study may serve as a basic data for the future study of shallow groundwater as a drinking water in agricultural area, in Korea.

• The Journal of Engineering Geology
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• v.17 no.3
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• pp.367-379
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• 2007

This study intended to evaluate hydrogeological characteristics in relation to subsurface geology data obtained from borehole, groundwater level, borehole flowmeter test, and field hydraulic tests. The regression equation of groundwater level (Y) versus ground elevation (X) is expressed by Y=0.75X-7.00 with quite high correlation coefficient of 0.78. Relationship between groundwater level and thickness of landfill, alluvium, and weathered zone results in higher correlation of groundwater level (Y) versus natural log value of weathered tone (A) than other correlations, with the regression equation Y= exp(9.974A)-14.155. The result of groundwater flow measurement in the boreholes indicates that groundwater flows towards between south and southwest, and this approximately agree with regional distribution of groundwater levels.

• Economic and Environmental Geology
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• v.27 no.3
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• pp.289-294
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• 1994

This paper describes an effective utilization method of well logging data and boring cores for understanding the geology of Keoje-do area. Six holes were drilled in 1988-1989, and all rock cores were recovered. Nevertheless, seven kinds of logs were carried out in each borehole. The geologic situations of the drilling sites are accurately evaluated from a comparison between core descriptions and well logging data. Porosities and clay contents of sedimentary rocks can be calculated using the data of density and gamma-ray logs. Fractured zones are easily detected from the change in inside diameter of borehole by caliper log. Sonic, density and gamma-ray logging data clearly indicate alternated and dyke zones; the former can be detceted from an acoustic wave attenuation and a decline of compaction by sonic and density logs, the latter can be detected from the amount of potassium contents of bed rock and dyke by gamma-ray log.

• The Journal of Engineering Geology
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• v.28 no.2
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• pp.175-182
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• 2018

We analyze geological, petrophysical and geomechanical characteristics of a $CO_2$ sequestration test site, Pohang. The target reservoir exists at a depth of 750 m, where porous and permeable sandstones/conglomerates prevail. The reservoir is underlain by thick mudstone formations. We estimate in situ stress conditions using an exploratory wellbore drilled through the target reservoir. The in situ stress condition is characterized by a strike-slip faulting favored stress regime. We discuss various aspects of reservoir fracture pressures and fault reactivation pressures based on the stress magnitudes.

• Economic and Environmental Geology
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• v.33 no.5
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• pp.435-442
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• 2000

Although the mummies of Lee Myeong-Jung and his wife who were a member of the Moon family, were buried in similar sites in around 1560, the degree of decay of the dead bodies and antiquities between two people were quite different. This study was focused on the cause of-those differences in terms of engineering geology. Cranular soil found several metered depth around the study site has good drainage ability and such characteristic could be a factor of excellent conservation of dead body. From the physical characteristics of the lime-containing material that is considered to be a barrier from water and air, it was observed that the material around dead body of wife was more compact and denser than that of husband. Such results could be a clear evidence that the lime containing material around dead body of wife was excellent barrier for keeping away from water and air. To investigate those differences of physical characteristics and constituent materials between two lime-containing materials, minerals had to be identified from the two materials. It was revealed that lime-containing material around dead body of wife contains gypsum and more calcite, which could be the reason for better barrier preventing from water and air than those around husband.

• Economic and Environmental Geology
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• v.29 no.1
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• pp.57-63
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• 1996

The Dalsung copper-tungsten mine in the Taegu area, Korea was closed in 1975 and may be the sources of the heavy metal contamination in the tributary system and soil-plant system due to the mine drainage derived from the mine wastes and tailings. To examine the degree and extent of heavy metal contamination in the vicinity of Dalsung mine area, stream water and soil samples were taken and analyzed for heavy metals by ICP-AES and AAS. Highly contaminated soils are found near the Lower Tunnel No.0 ranging up to $1760{\mu}g/g$ As, $2060{\mu}g/g$ Cu, $1120{\mu}g/g$ Pb and 346 ${\mu}g/g$ Zn. From the results of the sequential extraction methods for the metal speciation, the heavy metals in soils may be derived from soil parent materials and acid mine drainage. With the processes for the heavy metal removal, most of the heavy metal ions in the acid mine drainage are removed by being exchanged with Ca ions held by the bentonite, hydroxyapatite and calcium hydoxide.

• Economic and Environmental Geology
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• v.30 no.6
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• pp.637-644
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• 1997

Active young back-arc basin such as Mariana, Havre, Lau, Manus, East Scotia basins have asymmetric topography of two types in respect to the spreading axis. The arc-trench wing of Mariana Trough, Lau basin and Havre Trough are shallower toward the active arc, whereas those Manus and East Scotia basins are nearly symmetric to the opposite wings. The other asymmetry which shows the spreading axis deviated from the geographic axis toward the active arc is observed in each basin. Active young back-arc basins show a large variety of asymmetry rates ranging from the lowest East Scotia Basin to the highest Mariana Trough. The asymmetric topography of these young back-arc basins seems to be caused by the rollback rate of downgoing slab under the basin. As the rollback rate increases, the asymmetry rate systematically decreases.

• The Journal of Engineering Geology
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• v.2 no.2
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• pp.131-140
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• 1992

GIS(Geographic Information System) technology was applied for analysis of the potential degree of regional geologic hazard, especially landslide hazards in the suburb of Seoul City, whereby a regional geologic hazard map was produced. The factors causing a landslide such as slope geometry, geology, groundwater, soil property, rainfall and vegetation were incorporated through GIS in order to predict the potential hazards in this area. Cartographic simulation was finally made with these factors to produce a regional geologic hazard map. For this study, ARC/INFO and ERDAS systems were used in SUN 4-390 workstation.

• The Journal of Engineering Geology
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• v.7 no.3
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• pp.207-216
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• 1997

Estimation of loads on tunnel lining is one of the major issues to be addressed in the design of a tunnel. The existing analytical methods do not consider important details of construction and the variation of geology along the tunnel axis. The measured loads obtained from several sanitary and subway tunnels in Edmonton, Alberta, Canada, are compared with the lining loads calculated using the existing analytical methods. However, the existing methods are determined to be not fully satisfactory for the estimation of lining loads. To account for face and heading effects occurring prior to lining installation, the stress reduction factor determined using Eisenstein and Negro's method is used coupled with an analytical solution for calculation of lining loads.