• Title/Summary/Keyword: 대자율

Search Result 87, Processing Time 0.03 seconds

Relationship between Physicochemical Properties, Heavy Metal Contents and Magnetic Susceptibility of Soils (토양의 물리화학적 특성, 중금속 함량, 대자율 간의 상호관계 연구)

  • Chon, Chul-Min;Park, Jeong-Sik;Kim, Jae-Gon;Lee, Youn-Soo
    • Journal of the Mineralogical Society of Korea
    • /
    • v.23 no.4
    • /
    • pp.281-295
    • /
    • 2010
  • This paper deals with magnetic susceptibility, mineralogy, soil properties (pH, EC, CEC, loss on ignition), iron and manganese oxides, the content and partitioning of heavy metals (As, Cd, Cr, Cu, Ni, Pb, Zn), and their mutual relationship in the soil samples of an unpolluted, abandoned mine area, and industrial complex area. The various minerals derived from weathered bedrock were identified by X-ray diffraction in the unpolluted soil samples, except for the magnetic minerals. XRD analysis also revealed the existence of hematite and magnetite related to mine tailings and waste rocks in the abandoned mine area samples. The industrial complex area samples had carbonate minerals, such as calcite and dolomite, that might be due to anthropogenic deposition. The sum of the reducible, oxidizable, and residual fractions was over 80% for the abandoned mine area samples and over 50% for the industrial complex area samples using the sequential extraction method. The industrial complex area samples had a relatively high carbonate fraction that was associated with carbonate minerals. The content of aqua regia-extractable Fe, Mn, As, and Zn had a high positive correlation with the content of the dithionite-citrate-bicarbonate (DCB)-extractable method related to Fe/Mn oxide phases. The 54% and 58% of aqua regia-extractable Fe and As content, respectively, acted together with the concentrations of the DCB-extractable phases. Magnetic susceptibility values of total samples ranged from 0.005 to $2.131{\times}10^{-6}m^3kg^{-1}$. The samples including iron oxide minerals, such as hematite and magnetite, had a high magnetic susceptibility. The magnetic susceptibility showed a significant correlation with the heavy metals, Cd (r=0.544, p<0.05), Cr (r=0.714, p<0.01), Ni (r=0.645, p<0.05), Pb (r=0.703, p<0.01), and Zn (r=0.496, p<0.01), as well as Fe (r=0.608, p<0.01) and Mn (r=0.615, p<0.01). The aqua regia-extractable Fe and Mn content had a significant positive correlation with Cd, Cr, Cu, Ni, and Zn. However, the DCB-extractable Fe and Mn content had a significant positive correlation with As and Ni, indicating that the heavy metals were associated with Fe and Mn oxide minerals.

Integrated Interpretation of ERT Data from the Mineralized Zone in Geumpung Mine (금풍광산 광화대에 대한 전기비저항 토모그래피탐사 자료의 복합해석)

  • Jung, Yeon-Ho;Byun, Joong-Moo
    • Geophysics and Geophysical Exploration
    • /
    • v.10 no.4
    • /
    • pp.322-331
    • /
    • 2007
  • In this study, electrical resistivity tomography (ERT) were conducted to find the mineralized zone at the Geumpung mine in Dojeon-ri, Susan-myeon, Jecheon-si, Chungcheongbuk-do. The deviation of the inclined borehole was measured to obtain the exact positions of the electrodes for correcting apparent resistivity values from ERT. Geophysical loggings such as resistivity and natural gamma were conducted to obtain the properties of the material near the borehole. Measurements of the physical properties of the cores, such as porosity, water content, density, susceptibility, resistivity were performed to analyze the correlation between physical properties and resistivity. Grade analysis for core sample was also conducted to identify relationship between grade and resistivity. Rock property analysis shows that the resistivity is more dominated by susceptibility and grade than by porosity and water content in the mineralized zone. The results of ERT are well consistent with geophysical logging data and geologic column. So ERT is powerful method to identify conductive mineralized zone.

Physical property analysis of sediments for development of maritime archaeological survey techniques (수중문화재 탐사기법 개발을 위한 퇴적물 물성분석)

  • Kim, Sung-Bo;Ko, Eun-Ji;Jung, Yong-Hwa;Lee, Young-Hyun;Kim, Jin-Hoo
    • Journal of Advanced Marine Engineering and Technology
    • /
    • v.38 no.3
    • /
    • pp.333-341
    • /
    • 2014
  • Since distribution and preservation of cultural artifacts in the submarine sediments are directly affected by not only ocean currents and tides, but also their composition, it is very important to investigate geological characteristics of sediments and ocean-sediment interactions for maritime archaeological survey. Physical properties of submarine sediments, which are collected by grab sampler and vibro-corer, are analyzed in order to investigate effects of submarine environment on development of maritime archaeological survey techniques. Result of physical property analysis showed that bulk density, shear strength, and magnetic susceptibility increase with depth, while water contents and porosity decrease with depth. Since the magnetic susceptibility of bedrock is about 40 times that of submarine sediments, it might impact greatly on the response of magnetic survey. Physical properties of sediments with depth and sediment classification by Folk's ternary diagram indicate that submarine sediment mainly consists of silt, and cultural artifacts can not penetrate no deeper than 1.5 m in sediments.

Mass-Movement of Slope Material Since the Last Glacial Period at Angol Basin within Downstream Area of Gurongcheon in Cheonan, Choongnam Province (충남 천안 구룡천 하류부 안골유역의 최종빙기 이후 사면물질이동)

  • PARK, Ji-Hoon;PARK, Kyeong
    • Journal of The Geomorphological Association of Korea
    • /
    • v.17 no.3
    • /
    • pp.31-47
    • /
    • 2010
  • The history of mass movement has been reconstructed from the Angol basin in Guryongcheon drainage basin. Sedimentary facies study, radiocarbon dating, particle size analysis, magnetic susceptibility and geomorphological analysis have been performed to reconstruct the paleo-environmental history of Angol basin. From 40,480 to 9,850yrBP there were five periods of slope instability and from 9,850yrBP to present there were at least four periods of slope instability. Magnetic susceptibility curves match well with the sedimentary facies data. This study may help reconstruct the denudational history of the small basins in Cheonan area and could be the cornerstone of the paleo-climatological study of the Korean Peninsula.

Interpretation of Aeromagnetic Anomalies in the Southwestern Part of the Ogcheon Belt, Korea (옥천대 남서지역의 항공자력자료해석)

  • Baag Chang-Eob;Kang Taeseob;Lee Jung Mo
    • The Korean Journal of Petroleum Geology
    • /
    • v.4 no.1_2 s.5
    • /
    • pp.20-26
    • /
    • 1996
  • In order to uncover the subsurface geological structure in the southwestern rim of the Ogcheon Fold Belt including the Cretaceous Neungju Sedimentary Basin, we analysed and interpreted the aeromagnetic anomalies over the region. The study area belongs to Muan-gun, Yeongam-gun, Gangjin-gun, Jangheung-gun, and eastem Haenam-gun. From the qualitative analysis and quantitative modeling of the reduced-to-the-pole magnetic anomalies, following things are revealed or suggested; Even though the porphyry of higher susceptibility is not crop out in the Donggang Myeon in the northwestern part of the study area, it is supposed to have intruded the Precambrian gneiss and the Cretaceous Bulgugsa granite of lower susceptibility. Two-dimemsional modeling of profile data across the sedimentary basin of Neungiu Group reveals that the northern part of the basin is deeper than the southern part, and that the maximum depth of the basin is supposed to be $3\cal{km}$ below the surface. The western flank of the basin bottom is steeper than the eastern flank. The high susceptibility value of the Neungju Group sedimentary rocks indicates that the rocks comprises large amount of volcanic materials. This fact implies that it is hard to expect hydrocarbon reservoir in the sedimentary rocks of the Neungiu Basin.

  • PDF

A Petrological Study of Stones Used in the Three Storied Stone Pagoda of Bulguksa Temple (불국사 삼층석탑에 사용된 석재의 암석학적 연구)

  • Park, Sung-Chul;Moon, Sung Woo;Kim, Sa-Duk;Jwa, Yong-Joo
    • The Journal of the Petrological Society of Korea
    • /
    • v.24 no.1
    • /
    • pp.11-24
    • /
    • 2015
  • In this study, the stone used for three storied pagoda of Bulguksa Temple, which is easy to access due to works for dismantle and restore will be analyzed on the basis of petrographic study, magnetic susceptibility, and ${\gamma}$-ray spectrometer, and identify petrographic characteristics. Also we will select candidate areas of fresh rock to change the stone used for three storied stone pagoda as from its provenance is presumed. According to the results of visual inspection, the stones used for the three storied stone pagoda are similar to the features of Namsan granite, which is distributed around Gyeongju-si, and when it comes to the section of the stupa finial, the features of all the parts from the stupa finial is similar to Namsan granite except for the section of Jeweled cover. On the other hand, the color, the composition, and the mineral size of the stones in the section from the part of jeweled cover are similar to Tohamsan granite. As a result of none-destruction inspection, it seems that the stones used for the three stories stone pagoda except for the section of jeweled cover are similar to the values for the magnetic susceptibility and the ${\gamma}$-ray spectrometer. On the other hand, Jeweled cover and the values of Tohamsan granite are alike. Namsan granite is appropriate in case that the stone used for three storied stone pagoda must be replaced to fresh rock because of damage by weathering. Meanwhile, Namsan granite is seperated from Yangsan fault. Due to this fact, Namsan granite appears to not only Mt. Namsan in Gyeongju, but also Dongcheon-dong, Gyeongju, and Huenggok-ri, Pohang. As a result, these two areas are suitable to the candidate area to change the stone used for three storied stone pagoda.

Source Area of the Rocks Using the West Stone Pagoda of Gameunsaji Temple Site, Korea (감은사지삼층석탑(서탑)에 사용된 석재 공급지에 대한 연구)

  • Jwa, Yong-Joo;Kim, Kun-Ki;Ko, Seok-Bae;Kim, Jong-Sun
    • The Journal of the Petrological Society of Korea
    • /
    • v.15 no.3 s.45
    • /
    • pp.128-138
    • /
    • 2006
  • The west stone pagoda of Gameunssji temple site (National Treasure No. 112) has been damaged mainly by fracture, exfoliation and granular disintegration. In this study, the source area of the rocks using the west stone pagoda was examined in terms of petrological feature, magnetic susceptibility, and ${\gamma}-ray$ spectrometer. The stones include abundant crystal fragments of biotite, quartz and feldspars in the fine-grained matrix; they are petrographically discriminated to vitric-crystal tuff or crystal tuff. Measured magnetic susceptibility values are of from 10 to 20 $({\times}10^{-3}\;SI\;unit)$. From the ${\gamma}-ray$ spectrometer measurement K, eU, and eTh contents of the stones are about 3%, 0 to 8ppm, and 9 to 18 ppm, respectively. These features are used as indicators to presume the source area of the stones. Comparing the petrographical and chemical characteristics between the stones of the west stone pagoda and the country rocks near the Gameunsaji temple site, it is suggested that the most similar country rock to the stones could be dacitic volcanic rocks of the Beomgokri group in the Waeup basin. The Beomgokri group is lithostratigraphically divided into Waeupri tuff, Yongdongri tuff and Beomgokri volcanic rocks. Among the three rocks, the crystal tuff of the Beomgokri volcanic rocks seems likely to have been the source rock of the stones of the west stone pagoda.

Study on the Structure of the Korea-Japan Joint Development Zone by Means of Geophysical Data (지구물리 자료를 이용한 한일공동개발구역 일원의 구조 해석)

  • Jeongwon Ha;Sik Huh;Hyoungrea Rim
    • Geophysics and Geophysical Exploration
    • /
    • v.27 no.1
    • /
    • pp.23-36
    • /
    • 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.