• 한국지구물리탐사학회:학술대회논문집
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• 2003.11a
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• pp.501-503
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• 2003

Soil-gas radon level and other atmospheric factors have been measured at residual soil profiles that overlie granite bedrock which consists of major geology in Korea for 6 months from November, 2000 to April, 2001. Seasonal variations of soil-gas radon concentration are generally of greater magnitude than day-to-day fluctuations. The highest radon concentrations of 5,131 pCi/L measured during winter season and the lowest radon concentrations of 107 pCi/L during spring season. Two study areas, Bongcheon-dong(granite bedrock) and Seongnam-Yongin(gneiss bedrock) were investigated to assess the radon potential according to their field survey and emanation tests. The mean values of radon decrease in sequentially from Suji-A(813 pCi/L)>Suji-B(757 pCi/L)>Bundang-B(691 pCi/L)>Bundang-A(643 pCi/L)>Bongcheon-dong(513 pCi/L). Estimated soil-gas radon potential using maximum radon emanation ratios of each study area decreases in the order of Bongcheondong(950 pCi/L)>Suji-B(524 pCi/L)>Bundang-A(437 pCi/)>Bundang-B(259 pCi/L)>Suji-A(230 pCi/L) areas. The values of indoor radon and its daughter product concentrations in Bongcheon-dong area show that indoor basement rooms in poor ventilation condition could be classified as extremely high radon risk location of more than 4 pCi/L Rn and 0.02 WL.

• The Journal of the Petrological Society of Korea
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• v.18 no.2
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• pp.171-179
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• 2009

LA-ICP-MS U-Pb zircon age was determined from the granite gneiss from Jeungsan-Pyeongwon area located to the west of Pyeongan Basin, North Korea, yielding concordant age of $1,873{\pm}19(2{\sigma})$Ma interpreted as Paleoproterozoic granitic magmatism. Considering relatively precise data reported recently using SHRIMP and LA-ICP-MS, ages around 1,870 Ma have been most frequently reported from Precambrian basement rocks of Korean peninsula, including Yeongnam, Gyeonggi, and Nangnim massifs altogether. Geologic events of this period are interpreted as not only granitic magmatism but also hightemperature regional metamorphism depending on their localities. The magmatic and regional metamorphic events of similar periods have also been reported from neighboring cratons of both North China and South China. Therefore, we need more data and efforts to decipher correlation between Precambrian basements between Korea and China.

• Journal of the Korean Geotechnical Society
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• v.22 no.7
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• pp.55-64
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• 2006

Shallow failures of slopes in weathered soils are caused by infiltration caused by prolonged rainfall. These failures are mainly triggered by the deepening of the wetting band accompanied by a decrease in suction induced by the water infiltration. In this paper, hysteresis on soil-water characteristic curve (SWCC) of granite and gneiss weathered soils is investigated using transient flow analysis respectively. Each case was subjected to artificial rainfall intensities and time duration depending on the laboratory-based drying and wetting processes. The results show that the unsaturated seepage on weathered slopes are very much affected by the initial suction of soils and unsaturated permeability of the soils. In addition, a granite weathered soil has a lower air-entry value, residual matric suction, and wetting front suction and less hysteresis loop than a gneiss weathered soil.

• The Journal of the Petrological Society of Korea
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• v.13 no.4
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• pp.214-223
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• 2004

Oxygen and hydrogen isotopic compositions of the Jurassic peraluminous Hwacheon granite were measured, and compared with those of other Jurassic peraluminous Daebo granite in Korea. $\delta$$\^$18/O values for quartz and feldspar of the Hwacheon granite range from 8.2 to 10.6 and 5.8 to 9.0$\textperthousand$, respectively. Whole rock $\delta$$\^$18/O values for banded biotite gneiss country rocks surrounding the Hwacheon granites range from 8.1 to 9.4$\textperthousand$. Whole rock and biotite $\delta$D Values for Hwacheon granite range from -84 to -113 and -107 to -113$\textperthousand$, respectively. Whole rock $\delta$D values for banded biotite gneiss country rocks range from -76 to -100$\textperthousand$. Both $\delta$$\^$18/O and $\delta$D values of the Hwacheon granite are characterized by low values compared to the 'normal' values for the fresh peraluminous granitic rocks. Low $\delta$$\^$18/O values of the Hwacheon granite resulted from fluid-rock interaction for a long period. Isotopic modelling result renders that a relatively low-$\delta$$\^$18/O fluid below -1$\textperthousand$ was involved in subsolidus isotopic exchange under a relatively high fluid/rock ratio (<-6). The fluid of meteoric origin has experienced a modification of oxygen isotopic composition as a result of fluid-rock interaction with the Hwacheon granite and surrounding metapelitic country rocks.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.2 no.4
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• pp.1-8
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• 1999

Forest devastation in Korea was caused by several factors such as internal factors from geological features and external factors from artificial forest damages including fuel wood collection from forests, forest fires, shifting cultivations and so on. According to the reports of 1935, lots of forest devastation in Kyungpook province area occurred around the main and branch stream of Nakdong river. Main factors of occurring forest devastation in 1935 were investigated by the methods of forest devastation rate and the population density at the basin of Nakdong river. But based on our study, forest devastation mainly occurred in rock zones of granite and granite gneiss, next to Nakdong formation but scarcely occurred in Hayang formation. Clay of the weathered soils of granite and granite gneiss was lost by rainfall, but remaining coarse-sandy soils(or grits) have poored conditions in vegetation's growth, which are due to high level of water permeability, lack of water-holding capacity and dried conditions. Generally, pine forests are mainly growing up in these regions. It is supposed that forest devastation was accelerated due to long periods of natural regeneration and no ability of natural regeneration by sprout after frequent collections of fuel wood and cuttings from pine forest on those grit areas. These results indicated that the high rate of forest devastation occurred around the basin with the high resident population density, which was partly due to forest damages by fuel collection. Moreover, both geological features and number of residents had much influence on forest devastation. Forest devastation was positively correlated with those variables(r=+0.73).

• Magazine of the Korean Society of Agricultural Engineers
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• v.13 no.4
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• pp.2426-2438
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• 1971

Geology of the Dogdo Quadrangle consissed of metamorphosed sediments and granite. By microscopic observation the writer divided the former rocks into the feldspar quartz schist, biotite gneiss and sericite schist. The Seoul granite, which has intruded in the feldspar quartz schist, is distributed in the west half of the age Dogdo quadrangle. The Seoul granite is believed to have intruded in jurassic period, but the age of the metamorphic rocks is Pre-jurassic, though the schist and gneiss have been correlated to the Yeoncheon System of Precambrian. Soil samples were sampled from the locations where no contamination of other rockes is permitted. Results of mechanical analysis, PH and soil structure of the samples are shown, Soils from metamorphic rocks have been subjected to more weathering than granite soil though some of them have higher sorting coeffcient.

• Journal of Korean Society of Forest Science
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• v.22 no.1
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• pp.63-65
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• 1974

In this study, it is aimed to elucidate the relationship between the distribution of barren land in mountainous area and the geological and topographical characteristics of barren land in south Korea. To do this, the Land Use Classification Maps for mountainous areas (scale:1/50,000), compiled by the Roseources Survey Office of Mountainous and Forest Areas, Geological Maps of Korea (scale: 1/50,000), and Map of Geology of Korea (scale: 1,000,000), compiled by the construction Research Institute of Korea were used. The following conclusions have been obtained from this study. 1) Areas of strata that are most liable to dilapidation are found in such order of the broadest to broad as region of granite, granite-gneiss, and the specific stratum called the Kyongsang Stratum (named after the provinces) of the northern and southern Kyongsang Provinces comprising sandstones, gravelstones, crumblestones, and other stones similar to these species. These rocky hills occupy vast areas in size, so to speak, they are estimated to cover roughly 57% of the total barren and naked areas in the country. 2) The average size in area of barren and nated land, as one piece of land, 32 hectares of granite region, 15 hectares of granite-gneiss region and little less than 13 hectares of Kyongsang strata region were calculated.

• Korean Journal of Soil Science and Fertilizer
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• v.48 no.4
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• pp.255-261
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• 2015

Soil catena can be characterized by some properties, such as drainage levels and soil textures. Characteristics of soil catena are different drainage levels from a summit to the direction of gravity and similar soil textures. Therefore this study was performed GIS (Geographic information system) and statistical analyses using perimeters from soil series in order to characterize quantitatively and objectively soil distributional properties in Korea. The total of 16 soil series from representative granite and granite gneiss originated soils were selected among inland soils from detailed soil maps (1:25,000 scale) in Rural Development Administration (RDA) and analyzed. After the detailed soil maps were merged by soil series unit, perimeters were measured from one soil series to neighboring soil series using functions of table join, merge, dissolve, buffer, and clip in ArcGIS (10.1). The covering ratio of each soil series unit was calculated from neighboring perimeters by soil series and applied to clustering analysis. Soils that were analyzed were the total of 16 soil series; 7 of sandy loam and 9 of clay loam. As a result, analyzed soil series adjoined complicatedly such as Hyocheon series adjoined 26 series and Jisan did 276 series. The results of the clustering analysis showed that soils were clustered by soil textures except a few soil series. This study applied only one property that was a length of neighboring soil series to GIS and statistical analyses. These results were compared to existing soil groups that were classified by new-soil taxonomy, texture, soil type and drainage level. It showed that these analyses can provide soil characteristics by soil texture. Based on this study, there is a need to investigate further objectively and quantitatively in statistical analyses of soil series.

• Journal of the Korean earth science society
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• v.22 no.6
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• pp.528-547
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• 2001

The blastoporphyritic granite gneiss (BPGN) including much alkali-feldspar megacrysts occurs in Jiri mountains area, southwestern part of Sobaegsan massif, Korea. The BPGN is formed gneiss complexes with other gneisses in Precambrian. The BPGN was named as porphyroblastic gneiss with porphyroblasts of alkali-feldspar megacrysts by other researchers, but the BPGN includes of euhedral alkali-feldspars (microcline), and the boundary with the granitic gneiss represents sharp contact as intrusive relationship. The BPGN mainly composes of alkali-feldspar megacrysts, quartz, plagioclase, K-feldspar and biotite some almandine and accessary minerals are muscovite, chlorite, apatite, zircon and opaques. The alkali-feldspar is microcline with perthitic texture. An content of plagioclases show 30 to 40. Biotites occur two type, one is Brown biotite which shows compositional ranges of Mg/Fe+Mg ratios from 0.38 to 0.52, the other is Green Bt. which is retrograde product. Camels to be various sizes and shapes have composition of almandine with 73 to 80 mole percent, but represent retrogressive zoning from core (X$_{pyr}$: 15.9${\sim}$20.8) to rim (X$_{pyr}$:13.7${\sim}$15.9) to be evidence of retrograde metamorphism. Megacrysts of alkali-feldspar in the BPGN show rectangular shape of euhedral and some become ellipsoidal or spheroidal in shape and the average size up to 20 cm long. The megacryst includes of biotite, plagioclase and quartz, and rarely euhedral apatite as inclusions. In petrochemistry the BPGN represents granodiorite composition, characteristics of peraluminous S-type granitoid and calc-alkaline features.

• Economic and Environmental Geology
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• v.27 no.1
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• pp.11-28
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• 1994

The Anyang Feldspar Mine is located in Seoksu Dong, Anyang City, Kyeonggi Do, Korea and has a long exploitation record that is once produced high grade sodium feldspars, for glaze. Geologically, This area is mainly composed of Mesozoic Jurassic biotite granite (Anyang granite) which intruded Precambrian Kyeonggi Gneiss Complex outcroped near the mining area. The deposit is localized on the southwest hill side of Anyang granite batholith and is confined in hydrothemal alteration zone formed by sodium-rich alkali hydrothermal fluids along the fractures of leucocratic granite showing later differentiation facies in the biotite granite. The hydrothermal alteration is characterized by albitization, sericitization, and desilication. The microscopic observation and EPMA, XRD analysis of the feldspar ores show that major minerals are albite and quartz and accessory minerals are orthoclase and sericite, and they are rarely associated with perthite, fluorite, zircon, kaolinite, molybdenite, microcline and iron-oxide. In the REE pattern, the strong negative Eu anomalies of the feldspar ores indicate the influence of feldspar fractionation and show similiar pattern of the host leucocratic granite. The filling temperature of quartz crystals in ore zone ranges from $276^{\circ}C$ to $342^{\circ}C$, and it is inferred that the alteration occurred by the hypothermal solution.