• Journal of the Korean Geotechnical Society
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• v.21 no.5
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• pp.83-92
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• 2005

The aim of this study was to investigate damage conditions of cut slope structures due to acid rock drainage (ARB) and to assess the acid production potential of various rocks. Acid rock drainage is produced by the oxidation of sulfide minerals contained in coal mine zone and mineralization belt of Pyeongan supergroup and Ogcheon group, pyrite-bearing andesite, and Tertiary acid sulfate soils in Korea. Most of cut slopes producing ARB have been treated with shotcrete to reduce ARD. According to the field observations, ARD had an adverse effect on slope structures. The corrosion of shotcrete, anchors and rock bolts and the bad germination and growth diseases of covering plants due to ARD were observed in the field. The concentration of heavy metals and pH of ARD from cut slope exceeded the environmental standard, indicating a high potential of environmental pollution of surrounding soil, surface water and ground water by the ARD. According to acid base accounting (ABA) of the studied samples, hydrothermally altered volcanic rocks, tuffs, coaly shales, tailings of metallic mine had a relatively high potential of acid production but gneiss and granite had no or less acid production potential. It is expected that the number of cut slopes will increase hereafter considering the present construction trend. In order to reduce the adverse effect of ARD in construction sites, we need to secure the data base for potential ARD producing area and to develop the ARD reduction technologies suitable.

• Korean Journal of Environment and Ecology
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• v.26 no.1
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• pp.1-10
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• 2012

The habitats characteristics of Polypodium vulgare L. in Ulleung-do were investigated to compile basic data for conservation and restoration. Natural habitats were located at altitudes of 410~748m with inclinations of $12{\sim}80^{\circ}$. Sixty six vascular plants were identified from 10 quadrats in 4 habitats. Dominant species among the woody plants, based on importance value, were Acer pictum subsp. mono(49.52%) in the tree (T1) layer, Sorbus amurensis(28.99%) in the subtree (T2) and Schizophragma hydrangeoides(51.99%), Ligustrum foliosum(8.82%), Fagus engleriana(7.25%) in the shrub (S) layer. Importance value for members of the herb (H) layer were as follows: Polypodium vulgare 23.23%; Maianthemum dilatatum 9.65%; Phryma leptostachya var. asiatica 9.23%; Dryopteris crassirhizoma 8.40%; Carex shimidzensis 6.75% and Dystaenia takesimana 5.42%. The importance value of the last five species were high, so they were at affinity with Polypodium vulgare in their habitats. Species diversity was 1.18, and dominance and evenness were found to be 0.11 and 0.84, respectively. The soil types were sandy loam. Average field capacity was 30.42%, and the organic matter and pH were 17.95%, and 4.70. Correlation coefficients based on environmental factors, vegetation and soil analysis were showed that positive correlations between species diversity and species richness, whereas between species diversity and dominance, coverage of Polypodium vulgare and species richness were showed negative correlations.

• Journal of the Mineralogical Society of Korea
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• v.22 no.4
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• pp.297-305
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• 2009

Ores of the Jeonnam pyrophyllite province mainly consist of not only pyrophyllite but also kaolinite, and they usually contain minor amounts of muscovite and quartz. We usually call them as porcelaneous stones which usually show lower grade characteristics in the viewpoint of Korean nonmetallic industries. Mineralogical studies for the ores and their intimate formations revealed that another kind of clay minerals could have been produced from the volcanic sediments with similar ages and compositions. Corundum is commoner than the diaspore in the pyrophyllite deposits, and so diaspore can be regarded as one of temporary minerals from which corundum would be finally formed. Kaolinite deposits contain neither diaspore nor corundum, but alunites produced by an advanced argillic alteration are often observed in the upper portions of the kaolin ores. The lowest formation interbedded with pyrophyllite and/or kaolinite ores usually contain purple tuff bed on the uppermost part, and in ascending order, siliceous formation, fine ash tuff and lapillistone are found in the study areas. As ages are becoming younger, amounts of pyrophyllite and kaolinite are radically decreased, or disappeared completely. On the other hand, content of muscovite is slightly increased, and those of plagioclase feldspars and quartz are found to have been preserved from the original rocks during alteration process. Most of ore bodies show rather well bedded formations which are easily discernable in the outcrops, but more effective discremination is desirable where rather massive ores exist. Siliceous beds and purple tuff ones on the upper part of ore bodies would be useful as marker horizons or key beds which have distinct lithologies and extensions.

• The Journal of Engineering Geology
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• v.27 no.2
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• pp.153-164
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• 2017

The geological factors for causing ground subsidence are very diverse. It can be affected by any geological or extrinsic influences, and even within the same geological factor, the soil depression impact factor can be determined by different physical properties. As a result of reviewing a large number of papers and case histories, it can be seen that there are seven categories of ground subsidence factors. The depth and thickness of the overburden can affect the subsidence depending on the existence of the cavity, whereas the depth and orientation of the boundary between soil and rock are dominant factors in the ground composed of soil and rock. In case of soil layers, more various influencing factors exist such as type of soil, shear strength, relative density and degree of compaction, dry unit weight, water content, and liquid limit. The type of rock, distance from the main fracture and RQD can be influential factors in the bedrock. When approaching from the hydrogeological point of view, the rainfall intensity, the distance and the depth from the main channel, the coefficient of permeability and fluctuation of ground water level can influence to ground subsidence. It is also possible that the ground subsidence can be affected by external factors such as the depth of excavation and distance from the earth retaining wall, groundwater treatment methods at excavation work, and existence of artificial facilities such as sewer pipes. It is estimated that to evaluate the ground subsidence factor during the construction of underground structures in urban areas will be essential. It is expected that ground subsidence factors examined in this study will contribute for the reliable evaluation of the ground subsidence risk.

• The Korean Journal of Petroleum Geology
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• v.3 no.1 s.4
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• pp.28-39
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• 1995

The objective of this study is to investigate the origin of the dolomite in the Pungchon Formation of the Choseon Supergroup near Taebaeg City, Kangwondo, Korea. The Pungchon Formation is composed of limestone, dolomitic limestone, and dolomite with thin beds of flat pebble conglomerate (FPC) and mudrock. Texturally, the dolomite in the Pungchon Formation can be divided into four types; 1) coarse-sized, xenotopic dolomite in massive dolomite, 2) medium-siEed, idiotopic dolomite in flat pebble conglomerate, 3) xenotopic dolomite replacing ooids, algalnodules, and echinoderms, and 4) the dolomite in mottled fabric. The dolomite in mottled fabric can be subdivided into three types; a) coarse-sized, xenotopic saddle dolomite cement, b) medium-sized, idiotopic, cloudy-centered, clear-rimmed (CCCR) dolomite, and c) coarse-sized, idiotopic dolomite. The carbon isotopic composition of the Pungchon dolomite is in the range of $-2.8-1.4\%_{\circ}(PBD)$, suggesting that the carbon isotopic composition was buffered by the preexisting marine carbonates. Lighter oxygen isotopic values ($\delta^{18}O-15.7-8.7\%_{\circ}, PBD$) indicate that the Pungchon dolomite may have formed under high temperature in a burial diagenetic environment. The higher initial $^{87}Sr/^{86}Sr$ ratio of the Pungchon dolomite (0.7010-0.7161) than that of the coeval Cambrian seawater (0.7088-0.7092) indicates that dolomitizing fluids had been modified from the isotopic exchange with continental crust. Low Sr and Na contents(<200 ppm) of dolomite agree well with previously reported data for burial dolomite. Hifh Fe and Mn contents of the dolomite support the idea that the Pungchon dolomite may have formed in a deep burial diagenetic environment.

• Proceedings of the Korean Society for Information Management Conference
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• 2017.08a
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• pp.100-100
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• 2017

100년의 역사를 지닌 한국지질자원연구원(KIGAM)은 국내 유일의 지질자원 전문연구기관으로서 그간 생산한 조사 연구데이터는 우리나라 과학기술의 귀중한 역사적 학술적 가치가 큰 유산으로써 보존 가치가 매우 크다고 할 수 있다. 하지만 현재 KIGAM의 상황은 최종성과물 위주로 자료관리가 이루어지고 있으며, 조사 연구 과정에서 생산된 암석 토양 지하수샘플이나 조사 탐사장비를 통해 얻어지는 자료는 연구자 또는 연구실 팀에서 개별적으로 관리하고 있다. 이러한 자료관리체계는 자료의 공동 활용이 어렵고, 자료를 보유하고 있는 연구자의 퇴직이나, 조직개편으로 인한 팀 실의 분리 과정에서 자료의 손실과 훼손 가능성이 높고, 누가 어디에 어떤 자료를 무슨 형태로 보관하고 있는지 찾기 어려워 자료의 재활용도가 떨어질 뿐만 아니라, 이로 인한 중복 조사 연구 가능성도 배제할 수 없다. KIGAM은 지질자원분야 국가데이터센터 구축을 목표로 연구과정에서 생산되는 연구데이터의 체계적인 관리와 공유, 활용체계 구축을 위해 2015년도에 기획사업을 통해 중장기 로드맵을 포함한 추진전략을 수립하였으며, 한국과학기술정보연구원(KISTI)의 DataNest를 기술이전받아 지질자원 연구데이터 리포지토리 시스템(GDR: Geoscience Data Repository)를 개발하였다. GDR 시스템 개발을 위해 연구데이터 분류코드를 작성하였으며, 2016년부터 데이터관리계획(DMP: Data Management Plan)을 주요사업 연구계획서 양식에 포함시켜 제출하도록 하였다. 과거 KIGAM은 연구데이터를 수집, 관리하기 위해 몇 차례에 걸쳐 시도를 했지만 실패한 경험을 가지고 있다. 실패 요인에는 (1) 관련 정책, 제도, 조직, 인력, 예산 등 데이터 관리 인프라 부재, (2) 연구사업에서 생산된 데이터는 개인소유라는 인식 및 공유 의식 부족, (3) 데이터 관리 활동은 귀찮은 것이고, 시간 낭비라는 인식, (4) 데이터 관리 공개 공유 활동에 대한 보상체계 부재 등을 꼽을 수 있다. 즉, 제도를 포함한 인프라 부족과 경영진과 구성원의 인식부족이 제일 큰 원인으로 판단된다. 성공적인 연구데이터 관리를 위해서는 지속적이고 꾸준한 투자가 이루어져야 하지만 경영진의 의지에 따라 사업이 중단되기도 한다. 이러한 과거의 실패 요인에 대한 해결 없이 지난 1년 6개월 정도의 GDR 운영은 지지부진하였다. 이러한 문제점을 해결하기 위해서는 국가차원의 제도적 뒷받침이 따라야 한다. 즉 국가 R&D 성과물 관리차원에서 연구데이터를 주요 성과물로 관리해야 할 것으로 판단된다. 연구사업계획서에 DMP를 포함시키고, 연구주제 및 분야별로 데이터센터(혹은 데이터 리포지토리)를 지정하고, 국가 R&D에서 생산되는 연구데이터를 의무적으로 제출하도록 하는 것이다. 또한 데이터센터의 안정적이고 지속적인 운영을 위해 연구사업비 항목에 데이터 관리비를 신설하여 데이터센터의 운영비로 사용하도록 하면 예산문제도 어느 정도 해결 될 수 있을 것으로 본다. 또한 데이터 제출 및 인용도에 따라 데이터 생산부서 혹은 생산자에게 평가점수를 부여하는 등 보상체계 마련을 위한 연구도 필요할 것으로 보인다. 국가 R&D 연구데이터의 수집, 관리, 공유, 활용을 제대로 성공시키려면 국가 R&D 최고정책결정자의 지속적인 관심과 지원이 필수적이다.

• Economic and Environmental Geology
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• v.56 no.4
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• pp.385-396
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• 2023

The Mesozoic Bansong Group, distributed along the NE-SW thrust fault zone of the Okcheon Fold Belt in the Danyang-Yeongwol-Jeongseon areas, contains important information on the two Mosozoic orogenic cycles in the Koran Peninsula, the Permian-Triassic Songrim Orogeny and the Jurassic Daebo Orogeny. This study aims to review previous studies on the stratigraphy, depositional period, and basin evolution of the Bansong Group and to suggest future research directions. The perspective on the implication of the Bansong Group in the context of the tectonic evolution of the Korean Peninsula is largely divided into two points of view. The traditional view assumes that it was deposited as a product of the post-collisional Songrim Orogeny and then subsequently deformed by the Daebo Orogeny. This interpretation is based on the stratigraphic, paleontologic, and structural geologic research carried out in the Danyang Coalfield area. On the other hand, recent research regards the Bansong Group as a product of syn-orogenic sedimentation during the Daebo Orogeny. This alternative view is based on the zircon U-Pb ages of pyroclastic rocks distributed in the Yeongwol area and their structural position. However, both models cannot comprehensively explain the paleontological and geochronological data derived from Bansong Group sediments. This suggests the need for a new basin evolution model integrated from multidisciplinary data obtained through sedimentology, structural geology, geochronology, petrology, and geochemistry studies.

• Economic and Environmental Geology
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• v.56 no.3
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• pp.229-238
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• 2023

Bentonite is a type of rock that has been used as a traditional mineral medicine. It has a variety of pharmacological activities, and is used in traditional Korean medicine to treat jaundice, diarrhea, and hemostasis. In modern medicine, it is used as a raw material and additive for medicines such as antacids, gastrointestinal protective agents, and laxatives. Bentonite produced in Korea was produced through diagenesis or hydrothermal alteration of tertiary volcanic debris distributed in the Pohang and Gyeongju areas. It is mainly used for industrial purposes such as papermaking, paint, civil engineering, casting, and animal feed. Recently, technology is being developed to use it in cosmetics and pharmaceuticals. In this study, the geochemical characteristics of bentonite were identified by analyzing the main components and trace elements of 40 and 21 types of bentonite produced in the Gampo Gyeongju and Yeonil Pohang area. Also it were classifed by formation envrionment of bentonite deposits in the Gampo and Yeonil. As a result of the study, bentonite from the reserch area may be cased by argillic alteraton that alkali elements are removed form basaltic rocks by hydrothermal fluids and AI-CCPI alteration indices wrere also indentified argillic alteraton. It was found that there is a correlation between the behavior characteristics of heavy metal elements (P b, Cr, As) and the hydrothermal alteration of bentonite in the reserch area.

• Journal of Korean Society of Forest Science
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• v.113 no.1
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• pp.51-65
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• 2024

Phyto-sociological methods were used in this study to assess the vegetation structure of a forest stand at Mt. Goehwa in Sejong-Si with the aim of providing vegetation information for urban forest utilization and management plans. The actual forest vegetation was classified into two types of community groups (Quercus serrata-Lindera obtusiloba and Coreopsis lanceolata community groups) at the highest hierarchical level. The Q. serrata-L. obtusiloba community group was classified into six units, which included artificial forest and natural forest vegetation. Artificial forests were classified into three communities (Pinus rigida, Castanea crenata, and Robinia pseudoacacia), whereas natural forests were classified into three communities (Quercus variabilis, Quercus acutissimaa, and Pinus densiflora). The Coreopsis lanceolata community group, which exhibited vegetative characteristics of urban forest edge areas, was categorized into four units. The urban forest edges were classified into four communities (Indigofera bungeana, Lespedeza bicolor, Amorpha fruticosa, and Lespedeza cuneata). Accordingly, the vegetation structure of Mt. Goehwa was categorized into 10 vegetation unit systems. An importance value analysis showed the highest importance value for C. crenata at 6.7%, followed by P. rigida at 6.4%, and R. pseudoacacia at 6.3%, indicating that the ecological impact of plantation species can be significant on Mt. Goehwa. A community coefficient of similarity analysis revealed that the artificial and natural forests had similar species compositions; however, both forests differed from the urban forest edge. This variation was further confirmed by Detrended correspondence analysis(DCA), with similar results. Canonical correspondence analysis(CCA) showed that the artificial forest and natural forest community types were positively correlated with altitude, bare rock, and the present species. By contrast, the urban forest edge community types were negatively correlated with these factors.

• The Journal of Engineering Geology
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• v.29 no.2
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• pp.85-97
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• 2019

It can be observed that steep slopes ($65^{\circ}$ to $80^{\circ}$) consist of rock masses were kept stable for a long time. In rock-mass slopes with similar ground condition, steeper slopes than 1 : 0.5 ($63^{\circ}$) may be applied if the discontinuities of rock-mass slope are distributed in a direction favorable to the stability of the slope. In making a decision the angle of the slope, if the preliminary rock mass conditions applicable to steep slope are quantitatively setup, they may be used as guidance in design practice. In this study, the above rock mass was defined as a good continuum rock mass and the quantitative setup criterion range was proposed using RMR, SMR and GSI classifications for the purpose of providing engineering standard for good continuum rock mass conditions. The methods of study are as follows. The stable slope at steep slopes ($65^{\circ}$ to $80^{\circ}$) for each rock type was selected as the study area, and RMR, SMR and GSI were classified to reflect the face mapping results. The results were reviewed by applying the calculated shear strength to the stable analysis of the current state of rock mass slope using the Hoek-Brown failure criterion. It is intended to verify the validity of the preliminary criterion as a rock mass condition that remains stable on a steep slope. Based on the analysis and review by the above research method, it was analyzed that a good continuum rock mass slope can be set to Basic RMR ${\geq}50$ (45 in sedimentary rock), GSI and SMR ${\geq}45$. The safety factor of the LEM is between Fs = 14.08 and 67.50 (average 32.9), and the displacement of the FEM is 0.13 to 0.64 mm (average 0.27 mm). This can be seen as a result of quantitative representation and verification of the stability of a good continuum rock mass slope that has been maintained stable for a long period of time with steep slopes ($65^{\circ}$ to $80^{\circ}$). The setup guideline for a good continuum rock mass slope will be able to establish a more detailed setup standard when the data are accumulated, and it is also a further study project. If stable even on steep slopes of 1 : 0.1 to 0.3, the upper limit of steep slopes is 1 : 0.3 with reference to the overseas design standards and report, thus giving the benefit of ensuring economic and eco-friendlyness. Also, the development of excavation technology and plantation technology and various eco-friendly slope design techniques will help overcome psychological anxiety and rapid weathering and relaxation due to steep slope construction.