• Title/Summary/Keyword: Lithology

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Influence of Tectonic Uplift on Longitudinal Profiles of Bedrock Rivers: Numerical Simulations (융기가 기반암 하상하천의 종단곡선에 미치는 영향에 대한 연구 -수리 모형을 통한 연구-)

  • Kim Jong Yeon
    • Journal of the Korean Geographical Society
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    • v.39 no.5 s.104
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    • pp.722-734
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    • 2004
  • Longitudinal profiles of bedrock rivers play a fundamental role in landscape history by setting the boundary conditions for landform evolution. Longitudinal profiles are changed with climatic conditions, lithology and tectonic movements. Tectonic movement is an important factor controlling longitudinal profiles, especially in tectonically active area where uplift rates are regarded as a major factor controlling channel gradient. However study on bedrock channel has made little progress, because controls over bedrock river incision are yet to be clarified. Previous numerical simulations have used a simple diffusion model, which links together the overall processes of bedrock channel erosion as in other landform evolution models. In this study, previous bedrock incision models based on physical processes (especially abrasion) are reviewed and new modifications are introduced. Using newly formulated numerical model, the role of spatial pattern and intensity of tectonic uplift on changes in river longitudinal profile was simulated and discussed.

Study on Landslide using GIS and Remote Sensing at the Kangneung Area(II)-Landslide Susceptibility Mapping and Cross-Validation using the Probability Technique (GIS 및 원격탐사를 이용한 2002년 강릉지역 태풍 루사로 인한 산사태 연구(II)-확률기법을 이용한 강릉지역 산사태 취약성도 작성 및 교차 검증)

  • Lee Saro;Lee Moung-Jin;Won Joong-Sun
    • Economic and Environmental Geology
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    • v.37 no.5
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    • pp.521-532
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    • 2004
  • The aim of this study is to evaluate the susceptibility of landslides at Kangneung area, Korea, using a Geographic Information System (GIS) and remote sensing. Landslide locations were identified from interpretation of satellite image and field surveys. The topographic, soil, forest, geologic, lineament and land cover data were collected, processed and constructed into a spatial database using GIS and remote sensing data. Using frequency ratio model which is one of the probability model, the relationships between landslides and related factors such as slope, aspect, curvature and type of topography, texture, material, drainage and effective thickness of soil, type, age, diameter and density of wood, lithology, distance from lineament and land cover were calculated as frequency ratios. Then, the frequency ratio were summed to calculate a landslide susceptibility indexes and the landslide susceptibility maps were generated using the indexes. The results of the analysis were verified and cross-validated using actual landslide location data. The verification results showed satisfactory agreement between the susceptibility map and the existing data on landslide locations.

Conservation Treatment and Deterioration Evaluation of the Namwon Singyeri Maaeyeoraejwasang (Rock-Carved Seated Buddha Statue), Korea (남원 신계리 마애여래좌상의 손상도 평가 및 보존처리)

  • Chun, Yu Gun;Lee, Myeong Seong;Lee, Jae Man;Lee, Jae Jin
    • Journal of Conservation Science
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    • v.29 no.4
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    • pp.321-332
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    • 2013
  • Namwon Singyeri Maaeyeoraejwasang (Rock-Carved Seated Buddha Statue) is composed mainly foliated granite and is different metamorphic grade and weathering degree on rock location. As the results of deterioration evaluation, upper part of the buddha statue was estimated that granularity decomposition was serious and rock strength was lower than lower part. Furthermore organism assessed most effect of among weathering factors. Chl. a amount of organism species were calculated $0.2{\mu}g/cm^2$ of crustaceous lichen, $1.1{\mu}g/cm^2$ of foliose lichen, $2.3{\mu}g/cm^2$ of bryophyte. Organism was taken treatment in order of amount of Chl. a and pre-cleaning, dry cleaning, wet cleaning in sequence. It should be establish conservation plan that strengthening in consideration of lithology characteristics and setting in good condition environment to conserve long-term of Maaeyeoraejwasang.

Lithological and Structural Lineament Mapping from Landsat 8 OLI Images in Ras Kammouna Arid Area (Eastern Anti-Atlas, Morocco)

  • Es-Sabbar, Brahim;Essalhi, Mourad;Essalhi, Abdelhafid;Mhamdi, Hicham Si
    • Economic and Environmental Geology
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    • v.53 no.4
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    • pp.425-440
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    • 2020
  • The study area is located in the southern part of the M'aider Paleozoic basin in the Moroccan Eastern Anti-Atlas. It is an arid region, characterized by minimal vegetation cover, which can provide an ideal environment to apply remote sensing. In this study, remote sensing and field investigations were integrated for lithological and structural lineaments mapping. The Landsat 8 OLI data were processed in order to understand the role of lithology and geological structures in the distribution of mineral deposits in the study area. To achieve this purpose, the Color Composite (CC), the Principal Component Analysis (PCA) and Band Rationing transformation (BR) tests were performed. The results of remote sensing techniques coupled with field investigations have shown that the zones of high lineaments densities are highly correlated with the occurrences of barite mineralization. These findings depict a spatial relationship between structural lineaments and the mineralization distribution zones. Therefore, the barite and Iron oxides mineralization veins, which occur mainly in the Ras Kammouna district, seem to have a structural control. The methodological approach used in this study examining lithological mapping and lineament extractions can be used to explore mineral deposits in arid regions to a high degree of efficiency.

Detection of formation boundaries and permeable fractures based on frequency-domain Stoneley wave logs

  • Saito Hiroyuki;Hayashi Kazuo;Iikura Yoshikazu
    • Geophysics and Geophysical Exploration
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    • v.7 no.1
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    • pp.45-50
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    • 2004
  • This paper describes a method of detecting formation boundaries, and permeable fractures, from frequency-domain Stoneley wave logs. Field data sets were collected between the depths of 330 and 360 m in well EE-4 in the Higashi-Hachimantai geothermal field, using a monopole acoustic logging tool with a source central frequency of 15 kHz. Stoneley wave amplitude spectra were calculated by performing a fast Fourier transform on the waveforms, and the spectra were then collected into a frequency-depth distribution of Stoneley wave amplitudes. The frequency-domain Stoneley wave log shows four main characteristic peaks at frequencies 6.5, 8.8, 12, and 13.3 kHz. The magnitudes of the Stoneley wave at these four frequencies are affected by formation properties. The Stoneley wave at higher frequencies (12 and 13.3 kHz) has higher amplitudes in hard formations than in soft formations, while the wave at lower frequencies (6.5 and 8.8 kHz) has higher amplitudes in soft formations than in hard formations. The correlation of the frequency-domain Stoneley wave log with the logs of lithology, degree of welding, and P-wave velocity is excellent, with all of them showing similar discontinuities at the depths of formation boundaries. It is obvious from these facts that the frequency-domain Stoneley wave log provides useful clues for detecting formation boundaries. The frequency-domain Stoneley wave logs are also applicable to the detection of a single permeable fracture. The procedure uses the Stoneley wave spectral amplitude logs at the four frequencies, and weighting functions. The optimally weighted sum of the four Stoneley wave spectral amplitudes becomes almost constant at all depths, except at the depth of a permeable fracture. The assumptions that underlie this procedure are that the energy of the Stoneley wave is conserved in continuous media, but that attenuation of the Stoneley wave may occur at a permeable fracture. This attenuation may take place at anyone of the four characteristic Stoneley wave frequencies. We think our multispectral approach is the only reliable method for the detection of permeable fractures.

Interpretation of Provenance and Transportation Process for Bakseok of Geunjeongjeon Hall in Gyeongbokgung Palace, Korea (경복궁 근정전 박석의 산지와 운송과정 해석)

  • Choie, Myoungju;Lee, Chan Hee;Jo, Young Hoon
    • The Journal of the Petrological Society of Korea
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    • v.24 no.3
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    • pp.181-191
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    • 2015
  • The Bakseok of Geunjeongjeon Hall in Gyeongbokgung Palace is platy floor stone acting as drainage, protected glaring and sliding. The Bakseoks were composed of anisotropic medium-grained biotite granite with a weak myrmekitic texture. Interpretation of transportation process for the Bakseok and original granite provenance trace of and analyze of identity based on ancient writings and detail field survey. As a result, the very similar granite with the Bakseok in lithology, composition mineral, texture and geochemical characteristics was found around Mt. Nakgasan in the Seokmodo Island. There were interpreted stonework process of the Bakseok used exfoliation granite dome with physical weathering properties in Seokmodo Island, to get platy stone economically stonework at the state level as a minimized on burden of supply and men power.

Distribution of Clay Minerals in Soils on the Northern Drainage Basin of the Nakdong River (낙동강 북부 배수유역의 토양 점토광물 분포)

  • Lee, Bong-Ho;Jeong, Gi-Young
    • Journal of the Mineralogical Society of Korea
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    • v.21 no.4
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    • pp.349-354
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    • 2008
  • Semiquantitative mineralogical analysis of clays in soils was performed to understand the distribution of clay minerals in relation to bedrock lithology on the northern basin of the Nakdong River. The soils developed on the granitic bedrocks have high contents of kaolinite and smectite. mite was the major clay mineral in the soils from sedimentary bedrocks, with minor kaolinite, smectite, and intergrade (interstratified chlorite-smectite or hydroxy-interlayed vermiculite) clay minerals. Illite and kaolinite contents of the soils from metamorphic and volcanic bedrocks fall between those of the soils from the granitic bedrocks and those of the soils from the sedimentary bedrocks. The clay mineralogy of the soils depends on the compositions of bedrock minerals and their susceptibility to chemical weathering. The weathering of plagioclase resulted in the high kaolinite content of the soils derived from granitic bedrocks, while the soils derived from sedimentary bedrocks are abundant in residual illite.

A Study on the Research History of Stone Pagoda after Japanese Colonial (일제강점기 이후 석탑(石塔) 조사연구사)

  • Ji, Sung-Jin;Seo, Chi-Sang
    • Journal of architectural history
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    • v.20 no.1
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    • pp.61-75
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    • 2011
  • This study aims to investigate the changing aspects about research methodology of stone pagoda from the period of Japanese colonial to now. There were the differences in purpose, method and analysis of the research according to each period. In Japanese colonial period, the purpose of research was to make lists of almost stone pagodas in Korea. Following this, Japanese researchers conducted detailed research for academic purpose. They took measurements of stone pagodas and made drawings. After liberation the research was focused on the relics contained in pagodas. They proceeded to investigate the inner relics in order to attract the attention of the people. In the late 1900's, the repair works of cultural heritages were increased. Many reports of the repair works were released and sent to administration offices. The reports contained the change aspects of situation between before work and after with drawings or simple investigation documents. In the 1990's, the restoration works for important stone pagodas were started by the National Research Institute of Cultural Heritage. Since then, researches from various way - architectural and conservational researches about historical interpretation, shape, structure, proportion, technique, etc. - progressed for careful restoration and accurate study. In Recent years, various professional organizations(in the field of structure, physics, chemistry, biology, lithology, etc.) started to join the researches. Researches conducted studies directly with the stone pagodas, as well as conducting indirect studies with the stone pagodas, such as the structural stability of stone pagodas, the characteristics of rock, and conservation chemicals. Today the research project 'The preservation project of stone cultural property' is being conducted by the National Research Institute of Cultural Heritage. The purpose of this project is to gain more detailed and accurate investigation documents to be provided for the people. In conclusion, researches from various fields must be included in the research. Furthermore, a synthetic study should be done through comparing similar characteristics or different characteristics among many research results.

Distribution Characteristics of the Incised Meander Cutoff in Gyeonggi and Gangwon Provinces, Central Korea (경기${\cdot}$강원 지역 감입곡류 하천의 곡류절단면 분포 특성)

  • Lee Gwang-Ryul;Yoon Soon-Ock
    • Journal of the Korean Geographical Society
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    • v.39 no.6 s.105
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    • pp.845-862
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    • 2004
  • The aim of this study is to investigate distribution characteristics of incised meander cutoff in Gyeonggi and Gangwon Provinces of Central Korea. The density of meander cutoff is highest in the mountain rivers including Naerin and Dongdae flowing on Jeongseon-gun and Inje-gun of Gangwon Province. Most of meander cutoff process has been occurred repeatedly during the Quaternary period, especially concentrated in the period of climatic change between glacial and interglacial stages. In the aspect of the lithology, the density of cutoff is highest in sedimentary rock, but lowest in igneous rock. As for geological structure, its frequency is high at $11{\sim}20km$ westerly away from the Taebaek Mountains, at subsequent channel, lower part of resequent channel, and channels crossing the fault line. The relation between distance from the Taebaek Mountains and altitude is very obvious at the western side of the Taebaek Mountains. The values of altitude, height from riverbed, and stream order are highest at sedimentary rock and lowest at volcanic rock.

3-Dimensional Sequence Interpretation of Seismic Attributes in the Structurally Complex Area (복잡한 지질구조 지역에서의 3차원 탄성파 Attribute를 이용한 층서해석 사례)

  • Kim, Kun-Deuk
    • Geophysics and Geophysical Exploration
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    • v.2 no.3
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    • pp.149-153
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    • 1999
  • The study was performed as a part of 3-D exploration project of the South Con Son basin, where Korea National Oil Co. (KNOC) and SHELL Company are performing joint operation. In the structurally complex area, seismic facies or lap-out patterns, which are usually the tools for the conventional seismic stratigraphy developed by Exxon Group (Vail et at., 1977), are not easily identifiable. Therefore, stratigraphic informations are mainly extracted from seismic attribute maps of each sequence or systems tracts, and isopach maps in correlation with the stratigraphic information from the wells. The attribute maps of the sequence or systems tract boundaries and isopach map describe the variations of paleodepositional environments. The shape of the attribute maps of the boundaries is a reasonable description of the shape of the paleodepositional surface. With other maps such as isopach and structural maps, the variations of the parasequences in the systems tracts can be projected using the surface attribute maps. The reflection intensity attribute at each sequence or system tract boundary can be related to lithology, facies or porosity distributions. The azimuth attribute of source rock sequence can be used to identify the hydrocarbon migration patterns into the prospects. The overall risks of reservoir rocks, cap rocks, structure and hydrocarbon migrations were computed using the results of the study.

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