• Journal of Soil and Groundwater Environment
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• v.16 no.6
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• pp.143-149
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• 2011

In order to figure out the characteristics of radionuclides concentrations of nine provinces, we analyzed uranium and radon in 681 samples of groundwater. Most of uranium concentrations in each province were less than $10{\mu}g/L$, and Gyeongnam, Jeonnam, Jeju provinces did not have groundwaters exceeding the US EPA drinking water MCL ($30{\mu}g/L$) of uranium. The ratio of radon values exceeding US EPA drinking water AMCL (4,000 pCi/L) was 22.6% (154/681) and Gyeongnam and Jeju provinces had no groundwaters exceeding the AMCL (alternative maximum contaminant level). Uranium and radon concentrations in groundwaters of Gyeonggi, Chungbuk, Jeonbuk, Chungnam mainly composed of the Mesozoic granite and the Precambrian gneiss were relatively high, but the concentrations of Gyeongnam and Jeju widely comprised of the sedimentary rock and the volcanic rock were relatively low. A week correlation between uranium and radon values showed in Gangwon, Chungbuk, Gyeonggi provinces.

• Economic and Environmental Geology
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• v.19 no.1
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• pp.19-24
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• 1986

The Samkwang mine is one of gold deposits distributed mainly in the southwestern province (Chungnam) of the Korean peninsula. Golds occur in quartz veins aged of $223{\pm}4MA$ according to K-Ar age dating from muscovite in a pegmatitic quartz vein. Quantz veins intrude Precambrian biotite-granite gneiss and mica schist of unknown age. Fluid inclusions in the quartz show a range of homogenization temperatures from 159 to $274^{\circ}C$. A calculated temperature from the isotopes of the galena-sphalerite pair is $375^{\circ}C$. Two phases-fluid inclusions homogenized either by liquid or vapor phase are frequently observed in specimens over $260^{\circ}C$, which may indicate the boiling of the fluids. Pressure of formation of the quartz veins inferred by the homogenization temperatures of liquid-$CO_2$ bearing fluid is 1kb. Based on these data, it is assumed that the temperature of the formation of the Samkwang mine may lie in between $350^{\circ}-230^{\circ}C$. ${\delta}^{34}S_{{\Sigma}s}$ values of sulphide minerals show narrow range of +2.1 to +4.6, and show a trend of enrichments of $^{34}S$ in the fluid from deep to the surface. ${\delta}^{34}S_{{\Sigma}s}$ in the fluid estimated is less than 3 permil, suggesting sulphur fluid originated from the magma.

• Proceedings of the Korean Geotechical Society Conference
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• 2008.10a
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• pp.455-465
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• 2008

In this study, the load distribution and deformation of rock-socketed drilled shafts subjected to axial load are investigated based on small scale model tests. In order to analyze the effects of major influencing factors of end bearing capacity, Hoek-cell triaxial tests were performed. From the test results, it was found that the initial slope of end bearing load transfer (q-w) curve was highly dependent on rock mass modulus and pile diameter, while the ultimate unit toe resistance ($q_{max}$) was influenced by rock mass modulus and the spacing of discontinuities. End bearing load transfer function of drilled shafts socketed in rock was proposed based on the Hoek-cell triaxial test results and the field loading tests which were performed on granite and gneiss in South Korea. Through the comparison with pile load tests, it is found that the load-transfer curve by the present study is in good agreement with the general trend observed by field loading tests, and thus represents a significant improvement in the prediction of load transfer of drilled shaft.

• Proceedings of the Korean Geotechical Society Conference
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• 2009.09a
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• pp.233-242
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• 2009

Based on the data obtained from field investigation and soil testing to slope hazards occurrence section and non-occurrence section in crystalline rocks like gneiss, granite, and so on, a prediction model was developed by the use of a decision tree model. The classification standard of the selected prediction model is composed of the slope angle, the coefficient of permeability and the void ratio in the order. The computer program, SHAPP ver. 1.0 for prediction of slope hazards around an important national facilities using GIS technique and the developed model. To prove the developed prediction model and the computer program, the field data surveyed from Jumunjin, Gangneung city were compared with the prediction result in the same site. As the result of comparison, the real occurrence location of slope hazards was similar to the predicted section. Through the continuous study, the accuracy about prediction result of slope hazards will be upgraded and the computer program will be commonly used in practical.

• The Journal of Engineering Geology
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• v.12 no.2
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• pp.127-135
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• 2002

The relationship between the seismic velocity and RQD was estimated using the RQD data obtained from the optical borehole image processing and drill core logs and the seismic velocity measured from the PS logging. The seismic velocity and crack aperture show a high correlation in the granite in Yuseong area and banded gneiss in Paldang area. However, such a relationship cannot be found in the sedimentary rock in Sabuk area. In the sedimentary rock of Sabbuk area, the seismic velocity shows widespread distribution especially in the 0∼20mm range of accumulated crack aperture probably because the wide distribution of fracture zone in coaly shale results in the inaccurate measurements of the crack aperture.

• Korean Journal of Remote Sensing
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• v.5 no.2
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• pp.109-122
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• 1989

The ISODATA method, which is one of the most famous of the square-error clustering methos, has been applied to two Chungju multivariate data sets in order to evaluate the effectiveness of the regional lithological mapping. One is an airborne radiometric data set and the other is a mixed data set of the airborne radiometric and Landsat TM data. In both cases, the classification of the Bulguksa granite and the Kyemyongsan biotite-quartz gneiss are the most successful. Hyangsanni dolomitic limestone and neighboring Daehyangsan quartzite are also classified by their typical lowness of the radioactive intensities, though it is still confused with some others such as water-covered areas and nearby alluvials, and unaltered limestone areas. Topographically rugged valleys are also classified as the same cluster as above. This could be due to unavoidable variations of flight height and the attitude of the airborne system in such rugged terrains. The regional geological mapping of sedimentary rock units of the Ockchun System is in general confused. This might be due to similarities between different sediments. Considarable discrepancies occurred in mapping some lithological boundaries might also be due to secondary effects such as contamination or smoothing in digitizing process. Further study should be continued in the variable selection scheme as no absolutely superior method claims to exist yet since it seems somewhat to be rather data dependent. Study could also be made on the data preprocessing in order to reduce the erratic effects as mentioned above, and thus hoprfully draw much better result in regional geological mapping.

• Korean Journal of Soil Science and Fertilizer
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• v.4 no.1
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• pp.33-40
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• 1971

Using radioactive $^{40}K$ in potassium, a study was conducted to evaluate the potassium supplying power of different soil types developed on different parent materials. A conversion factor based on two parameters namely $\frac{available\;K_{soil}}{total\;K_{soil}}$ and $\frac{K_{plant}}{K_{soil}}$ was developed and found to be closely related to plant response. According to this characterization soils derived from the various parent materials were ranked as basalt >Silla series>gneiss>porphyry>granite${\gg}$schist. From the point of view of potassium response as measured by yield as similar response pattern was observed. That is, soils derived from basalt to be most responsive as compared to the other soils. The variations among the soils may be accounted for to their potassium bearing mineralogical composition and their stability.

• Journal of The Geomorphological Association of Korea
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• v.28 no.1
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• pp.1-12
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• 2021

This study tried to reveal relative surface denudation resistance and ranking by geologic types in the Southern Korean Peninsula using an 1:250,000 digital geologic map and ASTER GDEM. Among rock types such as igneous, sedimentary and metamorphic rocks, metamorphic rock showed the greatest resistance to surface denudation. The most resistant rock to surface denudation by geologic periods (e.g., the Precambrian, Paleozoic, Mesozoic and Cenozoic) was found from the Precambrian. Among the major tectonic settings in the Southern Korean Peninsula such as the Gyeonggi massif, Okcheon belt, Yeongnam massif, Gyeongsang basin and Pohang basin, the Okcheon belt indicated the greatest resistance. The most and least resistant rocks from the representative nine rocks in the Southern Korean Peninsula were Paleozoic limestone, and Cretaceous sedimentary rock and Cenozoic sedimentary rock, respectively. This study suggests that Paleozoic limestone, Cretaceous volcanic rock, Paleozoic sedimentary rock and Precambrian gneiss can be regarded as hard rocks with high elevation, steep slope and complicated relief, while soft rocks with low elevation, gentle slope and simple relief are Jurassic granite, Cretaceous sedimentary rock and Cenozoic sedimentary rock.

• The Journal of the Petrological Society of Korea
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• v.11 no.1
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• pp.1-16
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• 2002

The study area is mostly composed of Precambrian Gyeonggi gneiss complex, Jurassic Daebo granites, Cretaceous tonalite and dykes, and so on. On the basis of field survey and mineral assemblage, the granites can be divided into three types; biotite granite (Gb), garnet biotite granite (Ggb) and two mica granite (Gtm). They predominantly belong to monzo-granites from the modes. Field relationship and K-Ar mica age data in the surrounding area suggest that intrusive sequences are older in order of Gtm, Ggb and Gb. Gb and Ggb, major study targets, occur as medium-coarse grained rocks, and show light grey and light grey-light pink colors, respectively. Mineral constituents are almost similar except for opaque in Gb and garmet in Ggb. Gb and Ggb have felsic, peraluminous, subalkaline and calc alkaline natures. In Harker diagram, both rocks show moderately negative trends of $TiO_2$, MgO, CaO, $Al_2O_3$, $Fe_2O_3$(t), $K_2O$ and $P_2O_5$ as $SiO_2$ contents increase. Among them, $TiO_2$, MgO and CaO show two linear trends. From the trends and the linear patterns in AFM, Sr-Ba and Rb-Ba-Sr relations, it is likely that they were originated from the same granitic magma and Ggb was differentiated later than Gb. REE concentrations normalized to chondrite value have trends of parallel LREE enrichment and HREE depletion. One data of Ggb showing a gradually enriched HREE trend may be caused by garnet accompaniment. Ggb have more negative Eu anomalies than Gb, suggesting that plagioclase fractionation in Ggb have occurred much stronger than that in Gb. In modal (Qz+Af) vs. Op, Gb and Ggb belong to magnetite-series and ilmenite-series, respectively. From the EPMA results, opaques of Gb are magnetite and ilmenite, and those of Ggb are magnetite-free ilmenite or not observed. Bimodal distribution of magnetic susceptibility reveals two different granites of Gb (332.6 ${mu}SI$) and Ggb (2.3 ${mu}SI$). Based on the paleomagnetic analysis as well as modal analysis, the main susceptibilities of Gb and Ggb reside in magnetite and mafic minerals, respectively. They belong to S-type granite of non-magnetic granite by susceptibility value. In addition, $SiO_2$ contents, $K_2O/Na_2O$, A/CNK molar ratio and ACF diagram support that they all belong to S-type granites.

• The Journal of the Petrological Society of Korea
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• v.15 no.3 s.45
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• pp.154-166
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• 2006

Though there are more than 600 active and non-active dimension stone quarries in Korea, most quarries are small-scaled and non-active. Main dimension stone belt in Korea is distributed in the Wonju-jecheon-Mungyeong-Geochang-Jinan-Nanwon-Geogumdo area with NNE direction, which occupies about 50% of domestic dimension stone quarries. The other dimension stone belts occur in the Gangyeong-Iksan-Gimje area, the Pocheon-Ujeongbu area and the Boryeong area. The dimension stones in Korea have been produced from at least fifteen rock types: granite, diorite, syenite, gabbro, homblendite, basalt andesite, rhyolite, tuff felsite, sandstone, marble, gneiss, schist and slate. However, seven or eight rock types such as granite, diorite and marble are currently produced. The dimension stones are quarried out 87% from plutonic rocks (mainly granite and diorite), 6% from sedimentary rocks (mainly sandstone), and 3% from metamorphic rocks (mainly marble). Main rock types of the dimension stones are variable with respect to their production locality. In the Jeollanam-do area, most dimension stones are produced from diorite. Marble is mainly produced from the Gangwon-do and Chungcheongbuk-do areas. Black sandstone is exclusively quarried out from the Chungcheongnam-do area. Granite is most abundant dimension stone in Korea. Above 50% of the domestic dimension stones are medium-grained to coarse-grained granitic rocks, but fine-grained granite dimension stones have 10% of distribution. The color of the dimension stone varies with rock types. Most granite dimension stones have dominant colors of whitish gray and gray, which are produced from the Wonju, Gapyeong, Iksan, Namwon and Geochang areas. Pink-colored granites are rarely produced from the Mungyeong area.