• 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.

• Korean Journal of Soil Science and Fertilizer
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• v.45 no.6
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• pp.890-896
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• 2012

This study was conducted to evaluate soil erosion risk with a standard unit watershed in the upper Upper Nakdong River Basin according to soil characteristics and landuse using the spatial soil erosion map. The study area is $3,605.6km^2$, which consists of 2 subbasins, 35 standard unit watersheds (Andong basin 18, Imha basin 17). As a evaluation of soil erosion potential using the spatial soil erosion map, total annual soil loss and soil loss per area estimated $2,013{\times}10^3Mg\;yr^{-1}$ (Andong basin 979, Imha basin 1,034) and $6.1Mg\;ha^{-1}yr^{-1}$ (Andong basin 6.0, Imha basin 5.2), respectively. 54.2% of soil loss was originated from Arable land (Andong basin 49.0%, Imha basin 59.0%), and the area of regions, graded as higher "Moderate" for annual soil loss, was $201.7km^2$ (Andong basin 84.9, Imha basin 116.8). Average soil loss per area of unit watersheds by classification according to soil dominant parent material types ranked "Sedimentary rock group" > "Mixed group" > "Metamorphic rock group" > "Igneous rock group". In conclusion, the results of this study inform that the classification of soil parent material type would be effective for soil erosion analysis and interpretation in the Upper Nakdong River Basin.

• The Journal of the Petrological Society of Korea
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• v.18 no.4
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• pp.315-336
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• 2009

We have studied the orientational characteristics of microcrack frequency, it's length and density in Tertiary crystalline tuff from the northeastern part of the Gyeongsang Basin. 134 sets of microcracks on horizontal surfaces of 3 rock samples from Heunghae-eup were distinguished by enlarged photomicrographs of the thin sections. The variability in patterns among microcrack length-frequency histograms for three rock samples from different altitudes were derived. The pattern of histograms changes progressively from negative exponential form to log-normal form in proportion to altitude. The distribution pattern for rock sample no.1 from lower altitude shows the broad length distribution characterized by higher mean and median, and higher standard deviation. Meanwhile, this distribution pattern corresponds with characteristics of joint length distribution in sedimentary rocks of the lower part of the Gyeongsang Supergroup. The occurrence frequency of shorter microcracks increases toward both NW and NE directions from the $N0{\sim}10^{\circ}W$, with the dominant direction of $N80{\sim}90^{\circ}W$ and $N80{\sim}90^{\circ}E$, respectively. This distribution pattern represents the relative differences in formation timing among microcrack sets and the result of the new initiation of shorter microcracks. Meanwhile, the longest microcracks within $N60{\sim}70^{\circ}W$($L_{max}$:1.18 mm) and $N0{\sim}10^{\circ}W$($L_{max}$:0.80 mm) directions are seen, but this kind of microcracks are very limited in number. Whole domain of the directional angle($\theta$)-frequency(N), length(L) and density($\rho$) chart can be divided into five sections in terms of phases of the distribution of related curves. From the distribution chart, density curve shows five distinct peaks in the WNW-ESE($N70{\sim}80^{\circ}W$), NS~NNE-SSW($N0{\sim}10^{\circ}W$, $N10{\sim}20^{\circ}E$), ENE-WSW($N50{\sim}60^{\circ}E$), and nearly EW($N80{\sim}90^{\circ}E$) directions, respectively. Especially, main directions of faults correspond with the directional angle showing high density. Consequently, these distribution patterns of density curve reflect the representative maximum principal stress orientations suggested in previous studies.

• Korean Journal of Soil Science and Fertilizer
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• v.41 no.3
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• pp.223-227
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• 2008

This experiment was conducted to describe the distribution of stable isotope Cd in the mine tailing and uncultivated soils derived from different parent rocks (Igneous rock, Metamorphic rock, and Sedimentary rock) as well as the movement of Cd isotopes from soil to plants, soybean and pepper. The results showed that there was no significant difference in isotopic ratios in soil among the eight kinds of stable isotope of Cd. However the relationship among isotopic ratios of stable isotope of Cd in soils were classified to four types, linear type between $Cd^{106}/Cd^{111}$ and $Cd^{108}/Cd^{111}$, quadratic type between $Cd^{114}/Cd^{108}$ and $Cd^{111}/Cd^{110}$, reverse quadratic type between $Cd^{110}/Cd^{116}$ and $Cd^{108}/Cd^{116}$, and cluster type between $Cd^{110}/Cd^{113}$ and $Cd^{116}/Cd^{113}$. While the individual stable isotopes of Cd in root were remained except on the plot of pepper without mine tailing application. $Cd^{116}$, $Cd^{114}$, and $Cd^{112}$ played active roles among other stable isotopic Cds in bean and red pepper, and $Cd^{116}$ was ranked the highest abundance ratio. Contrary to crop itself, the abundance ratios of $Cd^{116}$ in bean and read pepper roots were decreased, and the ones of other Cds were relatively increased.

• Economic and Environmental Geology
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• v.40 no.5
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• pp.651-660
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• 2007

Acid drainage has been recognized as an environmental concern in abandoned mine sites for long time. Recently, the environmental and structural damage by acid drainage is a current issue in construction sites in Korea. Here, the author introduces the type of damages by acid drainage in construction sites and emphasizes the importance of geoscience discipline in solving the problem. Metasedimentary rock of Okcheon group, coal bed of Pyeongan group, Mesozoic volcanic rock. and Tertiary sedimentary and volcanic rocks are the major rock types with a high potential for acid drainage upon excavation in Korea. The acid drainage causes the acidification and heavy metal contamination of soil, surface water and groundwater, the reduction of slope stability, the corrosion of slope structure, the damage on plant growth, the damage on landscape and the deterioration of concrete and asphalt pavement. The countermeasure for acid drainage is the treatment of acid drainage and the prevention of acid drainage. The treatment of acid drainage can be classified into active and passive treatments depending on the degree of natural process in the treatment. Removal of oxidants, reduction of oxidant generation and encapsulation of sulfide are employed for the prevention of acid drainage generation.

• The Journal of the Petrological Society of Korea
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• v.6 no.1
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• pp.19-33
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• 1997

This study reports the results about the petrography and geochemical characteristics of 10 representative volacanic rocks. The Cretaceous volcanic rocks distributed in the vicinity of the Kageo island composed of andesitic rocks, dacitic welded tuff, and rhyolitic rocks in ascending order. Sedimentary rock is the basement in the study area covered with volcanic rocks. Andesitic rocks composed of pyroclastic volcanic breccia, lithic lapilli tuff and cryptocrystallin lava-flow. Most dacitic rocks are lapilli ash-flow welded tuff. Rhyolitic rocks consists of rhyolite tuff and rhyolite lava flow. Rhyolite tuff are lithic crystal ash-flow tuff and crystal vitric ash-flow tuff with somewhat accidental fragments of andesitic rocks, but dacitic rocks. The variation of major and trace element of the volcanic rocks show that contents of $Al_2O_3$, FeO, CaO, MgO, $TiO_2$ decrease with increasing of $SiO_2$. On the basis of Variation diagrams such as $Al_2O_3$ vs. CaO, Th/Yb vs. Ta/Yb, and $Ce_N/YB_N$ vs. $Ce_N$, these rocks represent mainly differentiation trend of calc-alkaline rock series. On the discriminant diagrams such as Ba/La and La/Th ratio, Rb vs. Y + Nb, the volcanic rocks in study area belongs to high-K Orogenic suites, with abundances of trace element and ternary diagram of K, Na, Ca. According to the tectonic discriminant diagram by Wood, these rocks falls into the diestructructive continental margin. K-Ar ages of whole rocks are from andesite to rhyolite $97.0{\pm}6.8~94.5{\pm}6.6,\68.9{\pm}4.8,\61.5{\pm}4.9~60.7{\pm}4.2$ Ma, repectively. Volcanic rocks in study area show well correlation to the Yucheon Group in terms of rock age dating and geochemcial data, and derived from andesitic calc-alkaline magma that undergone low pressure fractional crystallization dominated plagioclase at <30km.

• The Journal of the Petrological Society of Korea
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• v.22 no.2
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• pp.179-195
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• 2013

The study area, which is located in the southeastern part of the Jirisan province, Yeongnam massif, Korea, is mainly composed of the Precambrian Hadong southern anorthosite complex (HSAC), the Jirisan metamorphic rock complex (JMRC) and Cretaceous sedimentary rock which unconformably covers them. Lithofacies distribution of the Precambrian constituent rocks mainly shows NS and partly NE trends. This paper researched deformational phased structural characteristics of HSAC and JMRC based on the geometric and kinematic features and the forming sequence of multi-deformed rock structures, and suggests that the geological structures of this area was formed through at least three phases of ductile deformation. The first phase ($D_1$) of deformation happened due to the large-scale top-to-the SE shearing, and formed the sheath or "A"-type fold and the regional tectonic frame of NE trend in the HSAC and JMRC. The second phase ($D_2$) of deformation, like the $D_1$ deformation, regionally occurred under the EW-directed tectonic compression, and most of the NE-trending $D_1$ tectonic frame was reoriented into NS trend by the active and passive folding, and the persistent and extensive ductile shear zone (Hadong shear zone) with no less than 2.3~1.4 km width was formed along the eastern boundary of HSAC and JMRC through the mylonitization process. The third phase ($D_3$) of deformation occurred under the NS-directed tectonic compression, and partially reoriented the pre-$D_3$ structural elements into ENE or WNW direction. It means that the distribution of Precambrian lithofacies showing NE trend locally and NS trend widely in this area is closely associated with the $D_1$ and $D_2$ deformations, respectively, and the NS-trending Hadong shear zone in the eastern part of Hadong northern anorthosite complex, which is located in the north of Deokcheon River, also extends into the HSAC with continuity.

• Korean Journal of Mineralogy and Petrology
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• v.35 no.3
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• pp.313-331
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• 2022

Natural or native abiotic molecular hydrogen (H₂) is a major component in natural gas, however yet its importance in the global energy sector's usage as clean and renewable energy is underestimated. Here we review the occurrence and geological settings of native hydrogen to demonstrate the much widesprease H₂ occurrence in nature by comparison with previous estimations. Three main types of source rocks have been identified: (1) ultramafic rocks; (2) cratons comprising iron (Fe²⁺)-rich rocks; and (3) uranium-rich rocks. The rocks are closely associated with Precambrian crystalline basement and serpentinized ultramafic rocks from ophiolite and peridotite either at mid-ocean ridges or within continental margin(Zgonnik, 2020). Inorganic geological processes producing H₂ in the source rocks include (a) the reduction of water during the oxidation of Fe²⁺ in minerals (e.g., olivine), (b) water splitting due to radioactive decay, (c) degassing of magma at low pressure, and (d) the reaction of water with surface radicals during mechanical breaking (e.g., fault) of silicate rocks. Native hydrogen are found as a free gas (51%), fluid inclusions in various rock types (29%), and dissolved gas in underground water (20%) (Zgonnik, 2020). Although research on H₂ has not yet been carried out in Korea, the potential H₂ reservoirs in the Gyeongsang Basin are highly probable based on geological and geochemical characteristics including occurrence of ultramafic rocks, inter-bedded basaltic layers and iron-copper deposits within thick sedimentary basin and igneous activities at an active continental margin during the Permian-Paleogene. The native hydrogen is expected to be clean and renewable energy source in the near future. Therefore it is clear that the origin and exploration of the native hydrogen, not yet been revealed by an integrated studies of rock-fluid interaction studies, are a field of special interest, regardless of the presence of economic native hydrogen reservoirs in Korea.

• The Korean Journal of Petroleum Geology
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• v.6 no.1_2 s.7
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• pp.8-19
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• 1998

In the Sinri area located at the mid western boundary of the Jinan basin, the Manduksan Formation which mainly consists of coarse sandstone narrowly intercalated with shale and the alternation of sand and shale and the Dalgil Formation mainly of shale are distributed. It consists of four lithofacies, such as coarse sandstone, interbedded sandstone/shale, shale and volcanic rock lithofacies. All sediments are interpreted to be deposited by turbidity currents and free fallouts in a lacustrine basin. In these rocks many penecontemporaneous defomation structures are observed such as fold and thrust fault at large scale, and swelling, boudin structure, flame structure, load structure, ptygmatic fold and convolute bedding at small scale. All these structures are developed between upper and lower undisturbed sedimentary strata. Two large folds are similar folds, but lower one gradually developed into concentric shape. The swelling structures by convergence of the sediments are observed in the hinge area and the boudin structures are developed in the limb. The thrust faults including minor folds and sandstone lobes show duplex structure with asymmetric and kink fold on and below in front of the detached sandstone layer. Development of the swellings, boudins and lobes indicates the flexbility of the sediments during deformational episodes. The folds and thrust faults rarely contain fractures relative their scales and lithologies. This feature also indicates the retrievability of sediments during deformation. At the flanks of the thrust faults the normal faults are formed contemporaneously. The deformation structures at small scale such as flame structures, load structures, ptygmatic folds and convolute beddings are syndepositional and penecontemporaneous, which show the effects of tectonic movements. All these deformed sedimentary structures of the Sinri area suggest the continuing tectonic movements during and/or after deposition.

• The Journal of Engineering Geology
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• v.15 no.4 s.42
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• pp.447-462
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• 2005

The purposes of this study are to evaluate and discuss the importance of geochemical properties of soil materials that play an important role in the occurrence of the landslide, using analyses of microtexture, particle size distribution, XRC, and FE-SEM equipped with energy dispersive spectrum on soils collected from landslide slopes of gneiss, granite and sedimentary rock areas. Soils from gneiss and granite areas where landslides took place have much clay content relative to those from non landslide areas, particularly pronounced in the granite area. Therefore the clay content is considered a sensitive factor on landslide. Clay minerals contained in soils are illite, chlorite, kaolinite and montmorillonite. Especially the content of clay minerals in soils from the Tertiary sedimentary rocks is highest, with abundant montmorillonite as expandable species. It is believed that this area was much vulnerable to landslide comparable to other areas because of its high content of monoorillonite, even though there might be weak precipitation. Since no conspicuous differentiation in mineralogy between the landslide area and non landslide area can be made, the occurrence of landslide may be influenced not by mineralogy, but by local geography and mechanical properties of soils. Geochemical information on weathering properties, mineralogy, and microtexture of soils is helpful to better understand the causes and patterns of landslide, together with engineering geological analyses.