• Title/Summary/Keyword: 동남

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Mineralogical Characterization of Buserite from the Janggun and Dongnam Mines, Korea (장군광산과 동남광산에서 산출되는 부서라이트의 광물학적 특성)

  • Choi, Hun-Soo;Kim, Soo-Jin;Kim, Jeong-Jin
    • Journal of the Mineralogical Society of Korea
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    • v.18 no.4 s.46
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    • pp.259-266
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    • 2005
  • X-ray diffraction (XRD), Electron microprobe analyses (EPMA) and heating experiments were used for mineralogical characterization of natural buserites collected from the Janggun and Dongnam mines. They are closely associated with $7-{\AA}$ phase (usually rancieite) in manganese oxide ores of the supergene oxidation zones of manganese carbonate deposits. Electron microprobe analyses give the average formula $(Ca_{0.78}Mg_{0.64}Mn^{2+}\;_{0.45})Mn^{4+}\;_{8.03}O_{18}\cdot13.2H_{2}O\;and\;(Zn_{0.81}Ca_{0.77}Mg_{0.26})Mn^{4+}\;_{8.00}O_{18}\cdot10.9H_{2}O$ for buserite from the Janggun and the Dongnam mine, respectively. The basal reflection of buserite from the Janggun mine shifts continuously from $9.86\;{\AA}\;at\;40^{\circ}C\;to\;7.60\;{\AA}\;at\;90^{\circ}C$, but the buserite from the Dongnam mine shows tendency of decreasing intensity in the $9.67^{\circ}C$ peak and of increasing intensity in the $7.53\;{\AA}$ peak in the range of $40\∼90^{\circ}C$, showing no gradual shifting of peaks.

Analysis of Plate Motion Parameters in Southeastern South Korea using GNSS (GNSS를 활용한 한반도 동남권 지역의 지각 변동 파라미터 분석)

  • Lee, Seung Jun;Yun, Hong Sic
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.38 no.6
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    • pp.697-705
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    • 2020
  • This paper deals with an analysis of crustal movement for the sourthern part of Korean peninsula using GNSS (Global Navigation Satellite System) data. An earthquake of more than 5.0 occurred in the southeastern region of the Korean Peninsula, and it is necessary to evaluate the risk of earthquakes in various ways.In order to reveal long-term tectonic movement patten in Pohang and Gyeongju provinces, we derived crustal movement parameters related with elastic theory. We used GAMIT/GLOBK for analyzing seven-year interval GNSS data of CORS (Continuously Operating Reference Stations). The azimuth of velocity vectors trended generally about 110° with an mean magnitude of 31mm/yr.The main characteristics of the strain change for seven-year in Korea obtaind from our study. Direction of the principal axis of the maximum compression is ENE-WSW as a whole, through there are some exceptions. The mean rate of the maximum shear strain change is (0.11±0.07)μ/yr, that is approximately one third that of Chubu district, Central Japan. Taking into account our results, the mean rate of maximum shear in southern part of Korean peninsula is considered as reasonable. The mean azimuth of principal strain is about (85.4°±26.8°). There are some exceptions of azimuth because the average azimuth differ from the left and right side in Yangsan fault which are about (73.2°±21.5°) and (105.2°±17.0°) respectively, It is noteworthy that the high seismicity areas in the southern part of Korea peninsula almost coincides with the area of large strain rate. As a conclusion, it could be stated that the our study represents the characteristics of crustal deformation in the southern part of peninsula, and contributes to the researches on earthquake disaster management.