• Title/Summary/Keyword: 홍성지역

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Evaluation of Seismic Response Characteristics of Hong-Seong Area based on In-Situ and Laboratory Tests (현장 및 실내시험에 기초한 홍성지역 지진응답특성 평가)

  • 박덕근;김교원
    • The Journal of Engineering Geology
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    • v.11 no.1
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    • pp.25-35
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    • 2001
  • For the ground resrxmse analysis, both in-situ and laboratory testing techniques such as downhole, SASW, resonant column and torsional shear tests were perlormed for Hong-Seong area. The grOlmd upper 30m is classified as SD since it has an average shear wave velocity as 209m/s. The response specLrums obtained by site-specific analyses generally satisfied the seismic code, but near the resonance period the motion was evaluated to be higher than the code.

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Geochronological and Geochemical Studies for Triassic Plutons from the Wolhyeonri Complex in the Hongseong Area, Korea (홍성지역 월현리 복합체 내에 분포하는 트라이아스기 심성암류의 지질연대학 및 지구화학적 연구)

  • Oh, Jae-Ho;Kim, Sung Won
    • Economic and Environmental Geology
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    • v.46 no.5
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    • pp.391-409
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    • 2013
  • The Hongseong area of the southwestern Gyeonggi massif is considered to be part of suture zone that is tectonically correlated with the Qinling-Dabie-Sulu belt of China in terms of the preservation of collisional evidences during Triassic in age. The Wolhyeonri complex, preserved at the center of the Hongseong area, consists mainly of Neoproterozoic orthogneisses and Middle Paleozoic intermediate- to high-grade metamorphic schists, orthogneisses and mafic metavolcanics. The area includes various Middle to Late Triassic intrusives (e.g. dyke or stock). They are mainly monzonite and aplite with small intrusions of monzodiorit, syenite and diorite in composition. The SHRIMP U-Pb zircon ages yield 237 Ma to 222 Ma. The geochemistry of the studied Triassic intrusives show similar subuction- or arc-type signatures having Ta-Nb troughs, depletion of P and Ti, and enrichment of LILEs (large ion lithophile elements). In addition, the Triassic plutons in the Hongseong area, including those from this study, mostly possess high-K calc-alkaline to shoshonitic tectonic affinity. These results could be tectonically correlated to the post-collisional magmatic event following the Triassic collision between the North and South China blocks in China. Therefore, the Triassic plutons in the Hongseong area offer an important insight into the Triassic geodynamic history of the NE Asian region.

Estimation of Site Effects at Hongsung Based on 2-Dimensional Basin Modeling within Spatial Geotechnical Information System (공간 지반 정보 시스템을 활용한 2차원 분지 모델링 기반의 홍성 지역 부지 효과 평가)

  • Sun, Chang-Guk;Choo, Yun-Sik;Chung, Choong-Ki
    • 한국방재학회:학술대회논문집
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    • 2008.02a
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    • pp.253-256
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    • 2008
  • 지하 토사 조건 및 지질 구조는 지진 시 지반 운동의 증폭에 관련된 부지 효과에 매우 큰 영향을 미친다. 본 연구에서는 국내 홍성 지역을 대상으로 시추 조사와 현장 탄성파 시험을 포함한 현장 조사 및 지표 부근지질 정보를 획득하기 위한 부지 답사를 통해 부지 효과를 확인하였다. 홍성 지역은 1978년 계기 지진이 발생한 지역으로서 기반암 상부에 최대 약 50 m 두께의 풍화대 지층이 분포한다. 연구 대상 지역의 공간 지층 구조를 효율적으로 확인하기 위하여 지리정보시스템(GIS) 기법 기반의 지반 정보 시스템(GTIS)의 구축하였으며, 홍성 지역은 분지는 얕고 넓은 형상임을 확인하였다. 홍성 지역의 부지 지진 응답을 평가하기 위하여 대표 단면에 대한 2차원 유한 요소 해석을 수행하였다. 도출된 지진 응답으로부터 지반 운동이 기반암 상부 토사층을 통해 전단파가 전파되면서 증폭되고 분지 형상에 따른 전단파의 상호 작용으로 생성된 표면파로 인해 분지 경계 부근 진동 지속 시간이 증가됨을 확인하였다. 뿐만 아니라, 분지 내의 선정된 토사 부지들에 대해서 추가적인 1차원 유한 요소 지진 응답 해석을 수행하였으며, 본 연구 대상 분지가 매우 얕고 넓음에 따라 분지 경계 부근을 제외하고는 분지 내 대부분의 위치에서 2차원 지진 응답과 유사한 결과를 보였다.

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Insect Pests Occurrence and Control in Organic and Conventional Rice Paddy Field (유기 및 관행벼 재배지 충해 발생 및 방제에 관한 연구)

  • Lee Sang-Guei;Lee Yong-Hoan;Kim Ji-Soo;Lee Byong-Mo;Kim Mi-Ja;Shin Jae-Hoon;Kim Han-Myeng;Choi Doo-Hoi
    • Korean Journal of Organic Agriculture
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    • v.13 no.3
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    • pp.301-314
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    • 2005
  • Insect pests were surveyed in 5 Rice paddy field areas of Organic paddy field and conventional paddy field. At the each rice-growth period, the occurrence rate of 'Small brawn plant hopper was high at the case of duck raising and rice bran farming on middle stage of rice paddy field in Gang-Hwa region. The occurrence rate of Rice water weevil was high at the conventional paddy field on the early stage of rice paddy field in Yeo-Ju region. In the Hong-Seong region, the occurrence rate of 'Rice water weevil' and 'Green rice leafhopper' was high at the 'duck raising compare to the conventional farming on the early stage of rice paddy field. According to each period, the occurrence rate of insect was high at late stage of rice paddy field, and there was no difference between each region. It showed high-occurrence tendency at duck pasture farming rice paddy field. The major natural enemies were spiders and parasites. Theridiidae and Linyphiidae were highly occurred on the conventional farming rice paddy field in Hong-Seong. Web builders containing Theridiidae, Linyphiidae and Tetragnathidae was occurred more than wandering spiders containing Lycosidae, Clubionidae and Pisauridae at various regions, and then occurrence of spiders was different at the various regions but was not different at each farming system.

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Electric and Electromagnetic Surveys of the Hongseong Fault Zone (홍성 단층대에서의 전기, 전자 탐사 연구)

  • Kwon, Byung-Doo;Lee, Heui-Soon;Park, Gye-Soon;Oh, Seok-Hoon;Lee, Choon-Ki
    • Journal of the Korean earth science society
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    • v.24 no.4
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    • pp.361-368
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    • 2003
  • We have investigated the electric resistivity structure of the fault zone located in the Hongseong area where a big earthquake with M 5.0 occurred in 1978. Usually, Electric and Electromagnetic methods are broadly operated in the field of engineering works since these methods are effective to understand the distribution of geological weak zones - fault or fracture zones. We have conducted the dipole-dipole array resistivity method and MT(magnetotelluric) method and interpreted the resistivity distribution of the fault zone with the aid of various inversion methods. An MT survey was performed at 18 points along a 2.9 km survey line perpendicular to the fault line and a magnetic dipole source was used to enhance the S/N ratio in the high frequency. A Electric dipole-dipole array resistivity survey with the dipole length of 50 meters was carried out perpendicular to the fault. In view of two survey results, the fault marks the boundary between two opposite resistivity structures, especially the low resistivity zone is exhibited deeply through the prospective fault line. The result that the low resistivity zone is located at the center of the fault zone corresponds with the fact that the fault zone of the Hongseong area is active. We expect these results to provide basic information about the physical properties of fault zones in Korea.

The tectonic evolution of South Korea and Northeast Asia from Paleoproterozoic to Triassic (원생대 이후 트라이아스기까지의 남한과 동북아시아의 지구조 진화)

  • Oh, Chang-Whan
    • The Journal of the Petrological Society of Korea
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    • v.21 no.2
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    • pp.59-87
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    • 2012
  • Recent studies reveal that eclogite formed in the Hongseong area and post collision igneous rocks occurred throughout the Gyeonggi Massif during the Triassic Songrim Orogeny. These new findings derive the tectonic model in which the Triassic Qinling-Dabie-Sulu collision belt between the North and South China blocks extends into the Hongseong-Yangpyeong-Odesan collision belt in Korea. The belt may be further extended into the late Paleozoic subduction complex in the Yanji belt in North Korea through the Paleozoic subduction complex in the inner part of SW Japan. The collision belt divides the Gyeonggi Massif into two parts; the northern and southern parts can be correlated to the North and South China blocks, respectively. The collision had started from Korea at ca. 250 Ma and propagated to China. The collision completed during late Triassic. The metamorphic conditions systematically change along the collision belt:. ultrahigh temperature metamorphism occurred in the Odesan area at 245-230Ma, high-pressure metamorphism in the Hongseong area at 230 Ma and ultra high-pressure metamorphism in the Dabie and Sulu belts. This systematic change may be due to the increase in the depth of slab break-off towards west, which might be related to the increase of the amounts of subducted ocecnic slab towards west. The wide distribution of Permo-Triassic arc-related granitoids in the Yeongnam Massif and in the southern part of the South China block indicate the Permo-Triassic subduction along the southern boundary of the South China block which may be caused by the Permo-Triassic collision between the North and South China blocks. These studies suggest that the Songrim orogeny constructed the Korean Peninsula by continent collision and caused the subduction along the southern margin of the Yeongnam Massif. Both the northern and southern Gyeonggi Massifs had undergone 1870-1840 Ma igneous and metamorphic activities due to continent collision and subduction related to the amalgamation of Colombia Supercontinent. The Okcheon metamorphic belt can be correlated to the Nanhua rift formed at 760 Ma within the South China blocks. In that case, the southern Gyeonggi Massif and Yeongnam Massif can be correlated to the Yangtz and Cathaysia blocks in the South China block, respectively. Recently possible Devonian or late Paleozoic sediments are recognized within the Gyeonggi Massif by finding of Silurian and Devonian detrital zircons. Together with the Devonian metamorphism in the Hongseong and Kwangcheon areas, the possible middle Paleozoic sediments indicate an active tectonic activity within the Gyeonggi Massif during middle Paleozoic before the Permo-Triassic collision.

Geochronological and Geotectonic Implications of the Serpentinite Bodies in the Hongseong Area, Central-western Korean Peninsula (한반도 중서부 홍성지역 내에 분포하는 사문암체의 지질연대학 및 지구조적 의미)

  • Kim, Sung Won;Park, Seung-Ik
    • Economic and Environmental Geology
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    • v.49 no.4
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    • pp.249-267
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    • 2016
  • The Hongseong area of the central-western Korean Peninsula is considered to be a part of collision zone that is tectonically correlated to the Qinling-Dabie-Sulu belt of China. The area includes the elliptical-shaped serpentinized ultramafic bodies, together with mafic rocks. The studied bodies are in contact with the surrounded Neoproterozoic alkali granites at the Baekdong and Wonnojeon bodies and the Paleoproterozoic Yugu gneiss at the Bibong body. The Baekdong body contains the blocks of the Neoproterozoic alkali granites and the Late Paleozoic metabasites. The Bibong body also includes the Neoproterozoic alkali granite blocks. The Mesozoic intrusive rocks are also recognized at the Baekdong, Wonnojeon and Bibong bodies. On the other hand, the Early Cretaceous volcanic rocks are occurred at the Bibong body. The detrital zircon SHRIMP U-Pb ages of the serpentinites at three bodies range variously from Neoarchean to Middle Paleozoic at the Baekdong body, and from Neoarchean to Early Cretaceous at the Wonnojeon and Bibong bodies. Although serpentinization does not generally produce minerals suitable for direct isotopic dating, the youngest Middle Paleozoic age at the Baekdong body and the Early Cretaceous age at the Wonnojeon and Bibong bodies indicate the possible upper age limit for the (re)serpentinization. Especially, the Early Cretaceous serpentinization ages may be related to the widespread Early Cretaceous igneous activity in the central-southern Korean Peninsula. Age results for the serpentinite bodies and the included blocks of the studied serpentinized ultramafic bodies in the Hongseong area, therefore, provide several possible interpretations for the serpentinization ages of the ultramafic rocks as well as the geotectonic implications of serpentinization, requiring more detailed study including other serpentinized ultramafic bodies in the Hongseong area.

A Study on the Planning of the Settlement Environment considering Survey in the Periphery of Local Industrial Park in Hongseong, Chungnam (주민의식조사를 통한 홍성 일반산업단지 주변지역 정주환경 계획에 관한 연구)

  • Chang, Dong-Min;Park, Tong-So
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.12 no.4
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    • pp.1968-1975
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    • 2011
  • This study was performed to propose a development guide for the periphery of local industrial park in the region of Hongseng-gun located at the mid-west of Chungnam province., which is a representative agrarian society, has been approached to a super-aged society where the region shows a continuous decrease in population, and the composition ratio of old ages is about 17.1%. Also, the region is a period of a low ebb due to the traditional agriculture based industrial structure in producing mainly simple productions. Many local governments in agrarian and fishing regions have been efforted for luring some businesses in their regions by constructing industrial complex competitively in order to solve such structural problems in such local regions. However, in some cases, these efforts cause certain destructions in the local original natural environment due to such development of industrial complex and the decrease in the settlement environment of residents. The objective of this study is to establish a local development plan for building the sustainable and comfortable settlement environments based on the settlement of the residents and the labors in such industrial complex by preventing sprawl developments in the construction of general industrial complex. This study was processed as following procedures. First, this study drew the trend in the change of the local society of H-gun through collecting literatures and analyzing it. Second, this study proposed a proper level of settlement environments required to the development of surroundings in such industrial complex based on the survey of the consciousness of residents using a statistical method. Finally, this study proposed a development guide for the surroundings based on the proposed level of settlement environments.