• Title/Summary/Keyword: 퇴적 환경

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Battery of bioassays에 의한 소양호 표층 퇴적물의 환경독성평가

  • 문성환;정진애;류성민;이순애;김재현;정대교;김기영;황인영
    • Proceedings of the Korea Society of Environmental Toocicology Conference
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    • 2003.10a
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    • pp.154-155
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    • 2003
  • 호소 퇴적물은 일반 하천에 비해, 입자성물질의 침강속도가 느리고 한번 퇴적된 물질의 교반이 잘 일어나지 않는 안정된 상태를 유지한다. 그러므로, 퇴적토질의 변화는 수질 변화의 추이를 대변해 줄 가능성이 높다. 소양호는 유역면적 2,703$\textrm{km}^2$, 유로연장 166.2km, 만수면적 70$\textrm{km}^2$으로 국내 최대 상수원 인공호이다. 본 연구에서는 담수 퇴적토의 오염 여부를 판단할 수 있는 생물학적 시험기법들을 활용하여 소양호의 표층 퇴적토질을 평가하였고, 주변잠재오염원의 분포와 비교하였다.

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Sedimentologic Characteristics of Tidal Flat Sediments after the Construction of Sea Dyke in Kwangyang Bay, South Coast of Korea (호안 건설 후 광양만 조간대 퇴적물의 퇴적학적 특성)

  • Ryu, Sang-Ock;Sin, Yong-Sik
    • Journal of the Korean earth science society
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    • v.27 no.6
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    • pp.659-669
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    • 2006
  • In Kwangyang Bay, the south coast of Korea, surface sediments and sedimentation rates have been investigated to understand the distribution and variation of tidal flat sediments after the construction of sea dyke. The mean grain size of the surface sediments during autumn is coarser, and decrease from winter to summer except for temporarily coarsening in the early summer. The depositional processes are prevalent in spring, while erosional processes are dominant in summer and autumn. This seasonal variation of sedimentary processes show similar results monitored from 2001 to 2003 before the construction of sea dyke. In the northern area of the bay, net annual sedimentation rates show similar results monitored from 2001 to 2003 before the construction of sea dyke. However, in the western area of the bay, net annual sedimentation rates change from erosion-dominated to deposition-dominated environments. It is considered that the western area of the bay is changed to erosion-dominated environments, as a result of the changes of hydrodynamic conditions, caused by sea dyke construction.

Gugokri-Nongdari Sedimentary Succession and Environment in the Southwestern Eumsung Basin (Cretaceous), Korea (백악기 음성분지 남서부의 구곡리-농다리 퇴적층과 퇴적환경)

  • Ryang, Woo-Hun
    • Journal of the Korean earth science society
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    • v.39 no.6
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    • pp.545-554
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    • 2018
  • The Cretaceous Eumsung (Eumseong) Basin is a pull-apart basin, formed along a series of the Gongju strike-slip faults trending NE-SW. The Nongdari-Meer forest of the Gugokri area in the southwestern part of the basin is comprised of thick purple mudstone, intercalating conglomerate, pebbly sandstone, and green mudstone beds. The succession mainly consists of seven sedimentary facies: stratified conglomerate (C2), conglomerate encased in siltstone (CE), stratified pebbly sandstone encased in siltstone (PSE2), purple sandy siltstone (Zp), green sandy siltstone (Zg), purple mudstone (Mp), and green mudstone (Mg). Sedimentary environment is mainly indicative of alluvial-plain setting in an alluvial-to-lacustrine sedimentary system, developed in the southwestern part of the basin. Geological survey was fulfilled in succession of the Gugokri sedimentary system using 1:5000 topographic map, which resulted in a geological route map. This study newly suggested that there be fluvial systems showing ENE and NNE trends in the study area, based on data of palaeocurrent direction and sedimentary characteristics in new outcrops of the forest. The study also revised the precedent sedimentation model of the Gugokri system.

Characteristics of Sedimentary Environments in Gamak Bay based on Numerical Experiments (수치실험에 기초한 가막만의 퇴적 환경 특성)

  • Kim, Byeong Kuk;Park, Sung Jin;Lee, Moon Ock;Lee, Yeon Gyu;Kim, Jong Kyu
    • Journal of the Korean Society for Marine Environment & Energy
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    • v.17 no.2
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    • pp.70-80
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    • 2014
  • We carried out numerical experiments to understand sedimentary environments in Gamak Bay where is located in the center of the southern coast of Korea. Deposition rates in Gamak Bay appeared to increase in the autumn and spring whereas they appeared to decrease in the summer and winter. These seasonal variations qualitatively coincided with seasonal variations of Ignition Loss (IL) for surface sediments. Furthermore, deposition rates turned out to be prevalent compared to erosion rates in most areas of the bay. On the other hand, current measurement results at both the northeast and south mouths of the bay showed their residual components to flow into the bay. Therefore, we can conclude that contaminated materials flowing into Gamak Bay will precipitate to be deposited in the bay as long as there is no specific events such as dredging.

Seismic Stratigraphy and Depositional History of Holocene Transgressive Deposits in the Southeastern Continental Shelf, Korea (한국 남동해역 홀로세 해침퇴적층의 탄성파층서 및 퇴적역사)

  • Yoo, Dong-Geun;Kim, Seong-Pil;Lee, Chi-Won;Park, Soo-Chul
    • Economic and Environmental Geology
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    • v.44 no.4
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    • pp.303-312
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    • 2011
  • Analysis of high-resolution seismic profiles from the southeastern continental shelf of Korea reveals that the Holocene transgressive deposits consist of five sedimentary units characterized by retrograding or backstepping depositional arrangements. Unit I, forming a linear sediment body along the shelf margin, is an ancient beach/shoreface deposit formed during the early stage of transgression. During the transgression, the paleo-channels were backfilled with fluvial or coastal-plain sediments, forming Unit II as an incised-channel fill deposit. The near-surface sediment was reworked and eroded by shoreface erosion, forming a thin lag of sands (Unit III) on the midshelf. During the middle stage of the transgression, the shoreline may have stabilized at around 70 - 80 m below the present sea level for some period of time to allow the formation of sand ridge systems (Unit IV). Unit V in the inner shelf was deposited in an estuarine environment during the middle to late stage of transgression. Such transgressive stratigraphic architecture is controlled by a function of lateral changes in the balance among rates of relative sea-level rise, sediment input and marine processes at any given time.

Biogeochemical Organic Carbon Cycles in the Intertidal Sandy Sediment of Nakdong Estuary (낙동강 하구 갯벌 사질 퇴적물에서 생지화학적 유기탄소순환)

  • Lee, Jae-Seong;Park, Mi-Ok;An, Soon-Mo;Kim, Seong-Gil;Kim, Seong-Soo;Jung, Rae-Hong;Park, Jong-Soo;Jin, Hyun-Gook
    • The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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    • v.12 no.4
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    • pp.349-358
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    • 2007
  • In order to understand biogeochemical cycles of organic carbon in the permeable intertidal sandy sediments of the Nakdong estuary, we estimated the organic carbon production and consumption rates both in situ and in the laboratory. The Chl-a content of the sediment and the nutrient concentrations in below surface pore water in the sandy sediment were lower than in the muddy sediment. The sediment oxygen consumption rates were relatively high, especially when compared with rates reported from other coastal muddy sediments with higher organic carbon contents. This implied that both the organic carbon degradation and material transport in the sandy sediment were enhanced by advection-related process. The simple mass balance estimation of organic carbon fluxes showed that the major sources of carbon in the sediment would originate from benthic microalgae and detrital organic carbon derived from salt marsh. The daily natural biocatalzed filtration, extrapolated from filtration rates and the total area of the Nakdong estuary, was one order higher than the maximum capability of sewage plants in Busan metropolitan city. This implies that the sandy sediment contributes greatly to biogeochemical purification in the area, and is important for the re-distribution of materials in the coastal environment.

퇴적물의 산성화에 따른 우수관 퇴적물의 중금속 용출특성과 존재형태 연구

  • 이평구;유연희
    • Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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    • 2001.09a
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    • pp.249-253
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    • 2001
  • 퇴적물에 오염된 중금속의 지화학적 특성을 규명하고자, 연속추출방법을 이용하여 구성광물 과의 지구화학적 수반관계와 산성화에 따른 중금속 용출특성을 연구하였다. 용출실험과 연속추출 실험을 종합한 연구결과, 서울시 도로변의 하수퇴적물이 산성비와 같은 요인에 의해 pH 5.0정도의 약산성환경과 접촉하였을 때 중금속의 상대적인 용출특성은 Zn>>Cd$\geq$Co>Ni>Cu$\geq$Pb>Cr이며, 원소별 용출량은 Zn 40-90%, Cd 10-30%, Co 15-25%, Ni 5-25%, Cu 0-20%, Pb 0% 및 Cr 0% 이었다. 하수퇴적물에 오염된 Zn, Cd, Cu 및 Ni의 용출은 매우 우려할 만한 수준이며, 수계의 물리화학적 변화(pH 등)에 따라 이들 원소의 일부분이 용해되어 지표수 및 강물을 오염시킬 것으로 예상된다.

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Significance of Modern Analog Studies for Exploration and Development of Oil Sand (오일샌드 탐사 및 개발을 위한 현생유사퇴적환경 연구의 중요성)

  • Choi, Kyung-Sik
    • The Korean Journal of Petroleum Geology
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    • v.14 no.1
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    • pp.12-20
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    • 2008
  • Oil sands in Canada are representative example of unconventional resources whose reserve estimates are as large as those in Saudi Arabia. Typical reservoir rocks of oil sands consist of channel-related deposits formed in a tide-dominated depositional setting. The tidal deposits are commonly characterized by spatially complicated and heterogeneous properties. Successful engineering methods to develop oil sands require in-depth understanding in the spatial distribution of reservoir properties. Geological model for oil sand reservoir characterization can be built on the basis of comparative studies of ancient and modem analogues. In particular, modern analogue studies become increasingly indispensable, since they provide better understanding in the reservoir-rock forming process and more importantly in the external mechanism responsible for the reservoir heterogeneity. Tide-dominated environment along the west coast of Korea is considered as one of the most excellent modem analogues of oil-sand forming depositional environment. Korean tidal environment provides insights on the origin of mud breccia, facies and stratigraphic architecture which are key issues to the characterization of oil sand reservoirs.

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