• Journal of the Geological Society of Korea
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• v.54 no.6
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• pp.631-640
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• 2018

To understand the formation and evolution of a sedimentary basin in basin analysis and modelling studies, it is important to analyze the thickness and age range of sedimentary layers infilling a basin. Because the compaction effect reduces the thickness of sedimentary layers during burial, basin modelling studies typically restore the reduced thickness using the relation of porosity and depth (compaction trend). Based on the compilation plots of published compaction trends of representative sedimentary rocks (sandstone, shale and carbonate), this study estimates the compaction trend ranges with exponential curves and equations. Numerical analysis of sedimentary compaction is performed to evaluate the variation of porosity and layer thickness with depth at key curves within the compaction trend ranges. In sandstone, initial porosity lies in a narrow range and decreases steadily with increasing depth, which results in relatively constant thickness variations. For shale, the porosity variation shows two phases which are fast reduction until ~2,000 m in depth and slow reduction at deeper burial, which corresponds to the thickness variation pattern of shale layers. Carbonate compaction is characterized by widely distributed porosity values, which results in highly varying layer thickness with depth. This numerical compaction analysis presents quantitatively the characteristics of porosity and layer thickness variation of each lithology, which influence on layer thickness reconstruction, subsidence and thermal effect analyses to understand the basin formation and evolution. This work demonstrates that the compaction trend is an important factor in basin modelling and underlines the need for appropriate application of porosity data to produce accurate analysis outcomes.

• Geophysics and Geophysical Exploration
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• v.19 no.4
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• pp.212-219
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• 2016

The development of more advanced geophysical exploration techniques is necessary because the orebodies as yet discovered are increasingly changing in characteristics from shallow/high-grade to deep/low-grade. In this work, laboratory measurement of physical properties of rock samples and a field survey and interpretation of spectral induced polarization (SIP) have been conducted in a skarn metallic deposit, Gagok mine. The purpose of this study is that the applicability of SIP in the exploration of skarn metallic deposits is verified by the comprehensive interpretation between SIP characteristics of rocks obtained from the laboratory measurements and inverted survey results from the field data. In order to understand the SIP characteristics of each lithology, the data of eighty nine rock samples utilized in the previous studies were revaluated. The field survey was carried out using frequency of 0.25 Hz along a survey line designed for intersecting lithological boundaries and evaluating mineralized zones. The mineralized rocks were more conductive (low-resistivity) and capacitive (high-chargeability or strong-phase) than other rocks. Thus, SIP can be one of the very useful tools for the mineral exploration of the skarn deposits.

• The Journal of Engineering Geology
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• v.28 no.4
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• pp.619-630
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• 2018

The purpose of this study is to investigate the existence of faults and intrusive rocks in the volcanic rock mass of Ulleung-do using magnetic anomalies. The magnetic survey data show that basaltic (mafic) rocks have high magnetic anomalies and that trachytic (felsic) rocks have low magnetic anomalies, implying that the anomaly distributions can be used to distinguish between different volcanic rock types that may be covered by regolith (such as alluvial and colluvial deposits) and other sedimentary layers. Our results show that basaltic rocks are not present within the Nari caldera. However, outside the caldera, the occurrence of high magnetic anomaly values of >$1,000{\gamma}$ is presumed to reflect the existence of basaltic craters or volcanic vents that formed prior to the eruption of the trachytic rocks. In particular, the area with anomaly values of >$1,000{\gamma}$ in the vicinity of Namyang-ri, southwest of Ulleung-do, is interpreted as having a high probability of hosting a crater and vent originating from mafic volcanism.

• Korean Journal of Mineralogy and Petrology
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• v.35 no.3
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• pp.183-197
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• 2022

Geochemical data, including Sr-Nd-Pb-Mg-Zn isotopes, reported on the late Cenozoic intraplate basaltic rocks in the Korean Peninsula (Mt. Baekdu, Jeongok, Baengnyeong Island, Pyeongtaek, Asan, Ganseong, Ulleung Island, Dok Island, and Jeju Island) are summarized to constrain their mantle source lithologies, and the nature of mantle end-members required. In the Sr-Nd isotope correlation diagram, Jeju basalts plot in the field of EM2-type oceanic island basalts (OIB), while the other basalts fall in the EM1-type OIB field. In Pb-Pb isotope space, Jeju basalts show a mixing array between Indian MORB and EM2 component, whereas the other basalts display an array with EM1 component. The Korean basalts were derived from a hybrid source of garnet lherzolite and recycled stagnant slab materials (eclogite/pyroxenite, pelagic sediments, carbonates) in the mantle transition zone. The EM1 component could be ancient (~2.0 Ga) K-hollandite-bearing pelagic sediments that were isolated for a long period in the mantle transition zone due to their neutral buoyancy. The EM2 component might have been relatively young (probably Pacific slab) and recently recycled clay-rich pelagic sediments. Eclogite and carbonates are unlikely to account for the EM components, but they are common in the mantle source of the Korean basalts.

• Journal of The Korean Association For Science Education
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• v.28 no.8
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• pp.955-963
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• 2008

This study was conducted to assess any change in students' views on the nature of science (NOS) after lessons through the activities of model construction and pattern identification. The instrument used to examine NOS views was the Views of Nature of Science questionnaire (VNOS). Four students' responses on VNOS before and after instruction were analyzed. The two levels of their views, novice and expert, were judged by the authors based on criteria set by several science educators. The instruction consisted of six hours of the so-called black box and cube activities developed for model construction and pattern identification, respectively. Students' views were at the novice level in definition of scientific theory, tentativeness of scientific knowledge, difference of hypotheses, theories and laws, model construction, and creativity and imagination in experiments and investigations. Students' views on NOS knowledge such as model and theory have improved for two students after instruction. The improvement seemed to be due to an explicit approach using the activities of model construction and pattern identification. The factors of changes and no-changes of views on NOS were identified and discussed in terms of improvement of the views.

• Geophysics and Geophysical Exploration
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• v.27 no.1
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• pp.23-36
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• 2024

In this study, we analyze the structure of the Korea-Japan Joint Development Zone (JDZ) using gravity, magnetic, and seismic data. Gravity and magnetic data analysis confirmed that the Jeju Basin exhibits low anomalies compared to adjacent areas. We applied the total gradient to the Bouguer anomaly to identify basin boundaries, and computed the analytic signal from the total magnetic anomaly data to enhance the edges of the magnetic anomalies. The Taiwan-Sinzi Belt, exhibits high magnetic anomalies and crosses the center of the JDZ in the northeast-southwest direction; we presume that intrusive rocks are sporadic in the JDZ. The 3D inversion results of the gravity and magnetic data show a strong correlation between magnetic susceptibility and density (i.e. a low-density zone in the Jeju Basin and the Ho Basin, and a high magnetic susceptibility distribution in the Taiwan-Sinzi Belt). Comparison of the density and seismic profiles of the Jeju Basin shows that high densities are associated with sill, horst, and basement highs, whereas low densities are associated with basement low and grabens. These results suggest that interpretations based on seismic, gravity and magnetic data can effectively reveal the subsurface structure of the JDZ.

• Economic and Environmental Geology
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• v.52 no.6
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• pp.617-626
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• 2019

In this study, we investigated the petrographic characteristics and physical property of the Rock-carved Seated Buddha at Bugmireugam hermitage of Daeheungsa temple in Haenam. The Buddha Statue was carved on micrographic granite, and the rock was composed of the fine quartz encircled by orthoclase. The results of diagnosis for deterioration evaluation have shown a highly damage rate of black contaminants (8.4%) and crack index (6.6). The ultrasonic velocity have detected SW (slightly weathered) grade of weathering coefficient (mean 0.18). Various weathering factor on the surface of the Buddha Statue was affected by precious shelter, and physical property with ultrasonic was directly influenced by the structural characteristics and fissure of host rock.

• 한국생물공학회:학술대회논문집
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• 2001.11a
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• pp.329-332
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• 2001

The stability of red pigment isolated from RF101 was determined over a period of storage for the pH, light, temperature and various metal ions. The absorption maximum of red pigment was 510nm. Red pigment was stable from pH 5 to pH 9 and in dark conditions. It was also stable against temperature below $25^{\circ}C$ and in $K^+$, $Ca^{2+}$, $Mg^{2+}$, Antibacterial activity of RF101 showed growth-inhibitory activity against plant pathogens Agrobacterium spp.

• Mineral and Industry
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• v.16 no.1
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• pp.1-16
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• 2003

수천 년 전부터 인간생활에 이용되어온 일라이트-운모는 다른 광물자원에 비하여 사용량은 많지 않지만, 요업, 도료, 종이, 건축용 재료, 화장품 소재 및 전자부품과 전기 재료 등 여러 산업 분야에 널리 사용되고 있다. 일라이트-운모는 광물학적으로 같은 계열의 광물군임에도 불구하고 산출상태, 입도 및 용도의 차이에 따라 다른 광물자원으로 취급되고 있다. 특히 국내에서 일라이트는 용어상의 혼란과 불명확한 법정 등록광종 때문에 효율적인 자원관리와 연구개발이 곤란한 실정이다. 그러므로 일라이트를 비롯한 점토광물 자원에 대한 광업법규상의 개선과 제도적 정비가 시급히 요구된다. 국내에서 개발되고 있는 일라이트-운모의 광석 유형은 그 광물상과 산출상태에 따라 페그마타이트상 백운모, 운모편암상 백운모, 납석상 일라이트 및 점토상 일라이트로 구분된다. 일라이트와 운모는 서로 다른 용도로 사용되고, 그 용도에 따라 그 품위 및 품질 개념이 다르다. 일라이트-운모 광석의 품위 및 품질 면에서 가장 기본적인평가방식은 (1) 육안 및 편광현미경 관찰, (2) X-선회질 분석 및 (3) 화학분석인 것으로 생각된다. 특히 리트벨트법을 응용한 X-선회질 정량분석법은 일라이트의 품위를 산정하는데 유력한 수단이 될 수 있을 것으로 여겨진다. 국내 일라이트-운모 자원의 자원잠재성과 부가가치를 향상시키기 위해서는 광석에 대한 정확한 품위 평가를 바탕으로 가장 적절한 이용 분야를 모색해야 할 것으로 판단된다.

• Journal of the Mineralogical Society of Korea
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• v.25 no.1
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• pp.51-61
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• 2012

터키는 알파인 조산대 내의 테티얀 광상대(Tethyan belt)에 위치한다. 이 광상대는 섭입과, 충돌, 열개 운동으로 형성되었고 후기 백악기에서 신생대 화성암류와 오피올라이트(ophiolite)와 관련된다. 터키 지표의 5.5%를 덮고 있는 변성지괴는 북동부의 스트란야(Strandja), 카쟉(Kazdag), 서부의 멘데레스(Menderes), 중부의 키르세히르(Kirsehir), 남동부의 비틀리스(Bitlis)와 포투르지(Poturge)에 분포한다(그림 3과 4). 비교적 연구가 많이 진행된 서부지역의 변성지괴 연구결과에 따르면 변성작용연대는 선캠브리아기에서 올리고세이다. 변성상은 녹색편암상과 각섬암상에서 에콜로자이트상과 백립암상에 이른다(Yigit, 2009). 상기 여러 지괴는 여러 번에 걸쳐 변성작용을 겪었다. 서부의 멘데레스 지괴는 다섯 개의 변성상을 보여주고 있으며, 두 번째 변성작용까지는 알파인 조산운동 이전의 시기이다. 다양한 지질과 지체구조는 터키의 다양한 광상의 부존 가능성을 가능케 한다. 주요자원인 금-동-몰리브덴 광상은 주로 후기 백악기에서 신생대의 화산호와 관련된 반암동과 천열수 광상이다. 동-연-아연 광상은 VMS 중 쿠로코와 사이프러스형 광상과 MVT 광상에 속한다. 알려진 크롬광상의 대부분은 포디폼광상이며 알파인-오피올라이트 암석과 관련된다.