• Geophysics and Geophysical Exploration
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• v.11 no.4
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• pp.335-342
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• 2008

Electrical resistivity and seismic refraction surveys were conducted to investigate geologic structures and geotechnical characteristics of the subsurface, along with rock physical property measurements in Dokdo island. The survey results in Seodo island show that the fault adjacent to the fisherman's shelter is a normal fault and extended towards the NW direction, and that Bedded Lapilli Tuff in the downstream was more severely influenced by weathering and erosion than Trachy Andesite II in the upstream of the survey area. In Dongdo island, Trachy Andesite III and Scoria Bedded Lapilli Tuff were severely weathered and eroded, considered as weathered to soft rock formations, and their weathered zone becomes thicker towards the antiaircraft facility in the NE direction of the survey area. The study results also illustrate that Trachyte and Trachy Andesite are hardest, Massive Tuff Breccia is next, and Stratified Ash Tuff is the most soft rock in Dokdo island.

• Journal of Science Education
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• v.41 no.3
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• pp.426-446
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• 2017

The purpose of this study was to analyze undergraduate students' reasoning for solving a problem about a rock and investigate the roles and importance of critical evidence (CE) and critical resource models (CRMs) in abductive reasoning. Participants were 20 senior undergraduate students enrolled in a science major course in a university of education. They were asked to abductively infer geologic processes of sedimentary rocks having a lot of holes and represent them with models. Their reasoning were analyzed according to a scheme for modeling-based abductive reasoning. As a result, successful student reasoning was characterized by using a diversity of grains and lots of holes as CE, activating the sedimentary rock formation and weathering as CRMs, and combining the CRMs into a scientifically sound explanatory model (SSEM). By contrast, in the reasoning unsuccessful in proposing a SSEM, students activated the igneous rock (basalt) formation and deposition as resource models (RMs) based on the evidence of the holes in the rocks and diverse grains, respectively, and used the RMs to construct their own explanatory models (EMs). It was suggested that to construct SSEMs to solve earth scientific problems about rocks, students need to know what could be CE in a particular problem situation, take an integrative or systemic approach to a rock problem, use multiple RMs, and evaluate RMs or EMs in light of evidence.

• Economic and Environmental Geology
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• v.40 no.5
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• pp.661-673
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• 2007

Rock materials of the three-storied stone pagoda in the Cheongryongsa temple in Korea are mainly composed of gneissose two-mica granite and fine-grained granite. This stone pagoda shows structural instability due to cracks and breaking-out of the stones. The surface properties of the stone is highly degraded by various inorganic pollutants and epilithic biospecies. Therefore, this study carried out comprehensive deterioration diagnosis by non-destructive methods, and some conservation treatments base on the diagnosis were carried out to reduce weathering progress. As the treatments, the biospecies and lichen that covering on the stone surfaces were removed by dry and wet cleaning, and degraded concrete applied to the pagoda for restoration in the past was removed and repaired with epoxy resin. Oxidized iron plates inserted between the rock properties were also substituted titanium stainless steels. After all processes are completed, we sprayed consolidant on the rock surface. Finally, the ground of the stone pagoda was rearranged using small rock aggregates, and the fence was established for control of artificial deterioration by visitors and environmental maintenance.

• The Journal of Engineering Geology
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• v.16 no.4 s.50
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• pp.359-371
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• 2006

In this study, the soil characteristics are analyzed using the result of various soil tests as an object of the soil layer of natural slopes in landslides areas composed with gneiss, granite, and the tertiary sedimentary rock. To investigate the soil characteristics according to landslide and non landslide areas, soils are sampled from Jangheung, Sangju and Pohang. The landslides at three areas are occurred due to heavy rainfall in same time. The geology of Jangheung area, Sangju area and Pohang area is gneiss, granite, and the tertiary sedimentary rock, respectively. On the basis of the landslide data and the result of soil test, the soil characteristics at the landslide area and the differentiation between landslide area and non landslide area are analyzed. However soil characteristics have a little differentiation to geological condition, the uniformity coefficient and the coefficient of gradation of soils at the landslide area is larger than those of soils at the non landslide area. Also, the proportion of fine particle of soils at the landslide area is higher. The plastic limit of soils sampled from the granite and the sedimentary rock regions is larger than that sampled from the gneiss region. However the liquid limit is irrelevant to the geological condition. Also, the consistency of soils at the landslide area is smaller. The natural moisture content of soils in the sedimentary rock regions is larger than that of the granite and gneiss. It is mainly influenced by mineral composition, soil layer structure, weathering condition, and so on. The soils sampled from landslide area have higher porosity and lower density than those from non landslide area. It means that the soils of landslide area have poor particle size distribution and loose density. Therefore, the terrain slope with poor distribution and loose density is vulnerable to occur in landslides. Also, landslides are occurred in the terrain slope with high permeability. The permeability is mainly influenced by the soil characteristics such as particle size distribution, porosity, particle structure, and the geological origins such as weathering, sedimentary environment. Meanwhile, the shear strength of soils is little difference according to the geological condition. But, the internal friction angle of soils sampled from the landslide area is lower than that of soils from the non landslide area. Therefore, the terrain slope with low internal friction angle is more vulnerable to the landslide.

• Korean Journal of Soil Science and Fertilizer
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• v.6 no.3
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• pp.141-152
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• 1973

The mineralogical studies of the eleven sub-soil samples derived from granite, granodiorite, diorite and arkose sandstone, taken from apple orchards in the province of Kyungsangbukdo, Korea are made to investigate the relationships between the mineral weathering, soil forming processes and mineralogical composition. The fine sand fraction (less than 0.2mm) and the clay fraction (less than 2 micron) are dispersed with the shaker after hydrogen peroxide treatment for the removal of organic matter, and separated from each suspension by gravity sedimentation. The fine sand are observed by mineral microscope and the clay are observed by X-ray diffraction patterns, differential thermal analysis curves and infrared spectrum. The outline of the results are as follows. 1. The primary minerals ; Quartz, changed-feldspar, plagioclase, alkali-feldspar are dominant in almost all samples, and some samples contain an appreciable amount of hornblende, biotite, muscovite and plant opal. There are also those samples which contain very small quantity of pyroxene group, tourmaline, epidote, cyanite, magnetite, volcanic glass and zircon. They are mainly derived from weathering products of granite, granodiorite, diorite, arkose or its mixtures. 2. All samples contain expanding or nonexpanding $14{\AA}$ minerals, illite and kaolin minerals, and some samples contain chlorite, cristobalite, gibbsite, and those primary minerals as quartz and feldspar, but the quantities vary according to the parent matrials. 3. Non-expanding $14{\AA}$ minerals may be dioctahadral vermiculite which sandwiches gibbsite layer or chlorite in between layer lattices. 4. As for clay minerals, montmorillonite was principal component in the samples derived from weathering products of arkose sandstone and tertiary. Minerals which are derived from weathering products of arkose have kaolin minerals and vermiculite as their principal component, and minerals derived from weathering products of acidic rock group are generally classified into two groups, the kaolin mineral group, and the kaolin minerals and vermiculite group.

• Journal of the Mineralogical Society of Korea
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• v.13 no.2
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• pp.73-83
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• 2000

다덕 광산 폐석내 섬아연석과 함망간탄산염 광물의 풍화현상과 그에 따른 중금속의 거동을 조사 하였다. 섬아연석은 풍화초기에 극미립 산화철의 망상구조 집합체로 교대되었으며, 후기에는 자연황이 용해중인 섬아연석과 산화철 집합체 사이에 침전되었다. 산화철 집합체에는 As가 다량 함유되어 있다. 능망간석와 함망간 방해석은 함아연산화망간의 망상구조 집합체로 교대되었으며, 함망간방해서과 함아연산화망간 사이에는 스미소나이트가 침전되었다. 선택적 용해외 X선회절분석을 이용하여 감정한 결과, 함아연산화망간은 헤테롤라이트/하이드로헤테롤라이트인 것으로 판명되었다. Zn의 일부는 규산과 결합하여 입간 공극에 월레마이트로 침전되었다. 풍화 초기에 형성되는 극미립 산화철 및 함아연산화망간의 치밀한 망상 집합체는 풍화용액의 순환을 차단하여, 모광물의 풍화 반응을 지체시키는 지화학적 장벽 역할을 하였다. 이에 따라 망상구조 내에 조성된 국지적 미환경하에서 풍화중간산물들이 침전되었다. 이상의 연구 결과로 다음과 같은 사항을 추론할 수 있다. 섬아연석의 Fe와 함망간탄산염의 Mn은 각각 산화철과 산화망간으로 침전되어 산성화에 기여하였다. 폐광석 더미내 As의 활동도는 저결정질 산화철에의 흡착에 의해 조절되며, Zn의 활동도는 미소환경조건에 따라 하이드로헤테롤라이트/헤테롤라이트, 스미소나이트, 월레마이트 등의 다양한 이차광물의 용해도에 의하여 조절된다.

• Journal of the Korean association of regional geographers
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• v.17 no.2
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• pp.141-149
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• 2011

The formation of Sajapyeong Alpine Wetland was influenced by factors of drainage basin and its geology, and fire-shifting cultivation. Sajapycong drainage basin had a narrow outlet, Sijeon-cheon in it flowed relatively slowly. Bedrock in basin was weak to mechanical weathering, many rock detritus were, produced. Deforestation for reclamation using fire accelerated topsoil loss. Thus much sediments was supplied to Sijeon-cheon and deposited in the channel bed, and wetland was formed on channel marginal footslope. In Sajapyeong moor were Gullies formed along road. Because they blocked sediments and throughflow transferring into moor, moor became dry land. In order to prevent this drying, we have, to raise water level of a drain ditch to level of weathered bedrock to transfer throughflow into moor, modify the shape of ditch to be naturally irregular, and construct large boulders step on the Sijeon-cheon bed to prevent from lowering of its bed.

• Journal of Applied Tourism Food and Beverage Management and Research
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• v.13 no.2
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• pp.207-221
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• 2002

Wolaksan is a national park which has beautiful scenery with exposed rocks. The mountain is 1097 meters high and has 3 tops which are Jungang(the center), Arae(the lower part), Jjokduri. The highest point of the vertical cliff is 150m from the earth and the total circumferences of three tops is about 4km. These tops are easy to break by grains because they are from sedimentary rocks. Wolaksan is a bad mountain because the area is a Mosikjuk rocky area. However, the area around Wolaksan is thicky wooded and has many achievements and it makes good scenery. From top to southeastern, there are vertical cliff, The tops are originally from one but these are divided by partial weathering corrosion. The slide of path to Wolaksan is about 70。. The lower part of the mountain from Shinroksa to top has a gentle slope but there are a steep slope from the middle. Especially, the area has many rocks. The rocks of Wolaksan are almost granitic-gneiss or metamorphic rocks so it often fall down. Because of these fallen rocks, its valleys have great landscapes. The size of rock is less than 60cm. The landscapes of valleys such as Songgye, Dukju, Yonghwa are the main natural tourism resources.

• Proceedings of the Korean Geotechical Society Conference
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• 2004.03b
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• pp.904-909
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• 2004

The study area adjoins with Yangsan fault in Sangbuk-myeon, Samsam-ri, Kyongsang-namdo and consist of the natural steep slope. After drawing data layer which have altitude by using digital topography data, it is converted to lattice DEM of $10m{\times}10m$ size. From this, gradient map of unit lattice, slant direction map and shadow relif map are made. Using flow apportioning algorithm, upper slope contributing area and wetness index by established lattice can be calculated. Area that have high wetness index shows lineament structure of northwest-southeast direction, and this agrees with shear fracture system. The result of electricity specific resistance survey in the study area shows that area of high wetness index has low electricity specific resistance anomaly. That is, wetness index conforms with distribution of fractured zone that accompanied chemical weathering of rock. Therefore, wetness index can be used as the method of detecting fractured zones and judging the stability of the area.

• 보존과학연구
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• s.27
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• pp.43-61
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• 2006

In this study stone heritages of 533 which is to be investigated through the five years for national treasures and treasures from 2001 to 2005 have been analyzed by statistics for types of stone heritages and rocks, level of alteration in order to make full use of guiding principle in conservation management of stone heritages. The ratio of stone pagoda as a percentage of 34.5% in the stone heritages much higher than others and that is composed of granite(83.0%) in the igneous rock. In the weathering index of surface, a 37.5% of the national treasures were classified with the level 4 and46.3% of the treasure were the level 3 according to state. The present condition of organism distribution take up 30.6% for the level 3 and 22.1% for level 1. In structural stability index, a 40.6%of the national treasures and a 54.2% of treasure were ranked level 3.