• Title/Summary/Keyword: 암괴

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Morphology and Genesis of Block Fields on the Seoraksan National Park in Kangwon Province, Korea (설악산국립공원에 발견되는 암괴원에 관한 고찰)

  • Park, Kyeong
    • Journal of the Korean Geographical Society
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    • v.35 no.5
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    • pp.653-663
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    • 2000
  • 본 논문에서는 설악산 아고산대에 나타나는 산정형 암괴원에 관한 여러 가지 논의를 제시하였다. 이 암괴원은 산악인들에게는 너덜지대로 너리 알려져 있었으며, 설악산의 북쪽 황철봉과 귀떼기봉에서 대청에 이르는 서북주릉 상 화강암류의 기반암에 암괴원이 분포하고 있다. 이들 암괴원은 규모가 클 뿐망 아니라 암괴상에는 풍화쇄설물을 가지고 있는 나마(gnamma)와 그루브(groove)를 비롯한 많은 화학적 풍화에 의한 미지형들이 발견되고 있어 한반도의 제 4기 후반의 기후변화와 지형형성 영력을 연구할수 이는 기후지형학적으로 중요한 연구지역이라 하겠다. 본 논문에서는 추후 발표될 암괴원의 성인과 고기후학적 의의에 관한 논의에 앞서 먼저 분포지역에 대한 소개와 몇 가지 이론적 고찰에 관하여 논의를 제한하고자 한다. 국내에서는 테일러스, 암괴류 등에 관한 논의가 상당히 이루어지고 있으나 암괴원에 관한 본격적인 논의는 아직 시작단계에 있다. Landsat 영상에 의한 구조선 분석 결과 구조선 밑도는 설악산 지역에서 큰 차이를 나타내지는 않으며, 암괴원은 대부분 화강암 지역에서 나타나는 것으로 판단된다.

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Type and Characteristics of Debris Landform in Mt. Mudeung (무등산 암설지형의 유형과 특징)

  • Oh, Jong-Joo;Park, Seoung-Phill;Seong, Yeong-Bae
    • Journal of the Korean association of regional geographers
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    • v.18 no.3
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    • pp.253-267
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    • 2012
  • The study looked into the type and characteristics of debris landforms in Mt. Mudeung. By focusing on the representative area, we aimed to categorize the debris landforms based on the morphologic and genetic characteristcis. The types of debris areas in Mt. Mudeung can be divided into the exposed debris type, mixed type of matrix, and the boulder-hidden type. Supply of block in the debris slope area displays different features depending on types of rocks. For the stony slopes of andesite, the block must be moved from the columnar joint or cliff in the upper part. The andesite debris slopes display dominant edge shape while displaying no round shape. The granite stony slopes display dominant round shape and the present exposed slope was assumed to be formed as the core stone which was deep weathered moved along slope during the periglacial era and the matrix was removed after post-glacial era. The movements of blocks are assumed to be caused by solifluction process. The joint area where granite and andesite areas meet, granite is located beneath andesite area, and this implies that blocks were actively freezing and creeping by solifluction and freezing and thawing at that time. It can be assumes that the granite matrix formed plain slope and then andesite boulder covered up the slope. Currently, the blocks in the stony slopes of Mt. Mudeung shows almost no mobility and the stony slopes created under periglacial climate can be considered to be fossil landform.

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Blockfields of Seoraksan National Park: Age and Origin (설악산 국립공원 지역 아고산대의 암괴원의 기원과 연대에 관한 고찰)

  • Kyeong Park
    • Journal of the Korean Geographical Society
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    • v.38 no.6
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    • pp.922-934
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    • 2003
  • On top of several peaks of Seoraksan National Park. many extensive blockfields are found. After initial report was made in year 2000, further field work and analysis of satellite image have been made. Blockfields on top of mountain peaks exhibit evidence of chemical weathering including gnammas and grooves. Also, several lichen colonies larger than 80 cm in diameter have been found on the surface of many blocks. High resolution IKONOS image has been used to delineate the boundary of blockfields which are hard to access during the field trip. Blockfields of Mt. Seoraksan lack fine material necessary for age dating and clay mineral analysis because they experienced long period of wash and erosion during the Holocene. The ages of blockfields seem to be pre-Holocene on the basis of size of lichen colony and weathering pits.

Evaluation of Crack Behavior and Climate Monitoring of Ipseok-dae Columnar Joints and Jigong Neodeol Rock Blocks in Mudeungsan National Park (무등산국립공원 입석대 주상절리 및 지공너덜 암괴의 균열 거동과 기후 모니터링 평가)

  • Noh, Jeongdu;Kang, Seong-Seung
    • The Journal of Engineering Geology
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    • v.31 no.4
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    • pp.621-630
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    • 2021
  • This study evaluated cracks and climate monitoring in Ipseok-dae columnar joints and Jigong Neodeol rock blocks in Mudeungsan National Park. The rocks' state of cracking and their surface temperatures were measured alongside air temperature, relative humidity, and wind velocity. The maximum crack behavior in Ipseok-dae was 0.367 mm at one point, and showed a slight tendency at other points. One in Jigong Neodeol was within 0.15 mm and showed a stable state with little change. The surface temperature of the Ipseok-dae columnar joints was higher on the side exposed to sunlight than on the shaded side. All blocks of Jigong Neodeol rock showed similar temperatures. The air temperature showed a similar distribution for both rock types. The air temperature showed a similar distribution for both Ipseok-dae and Jigong Neodeol. The relative humidity was mostly between 20% and 60% in Ipseok-dae and was between 20 and 70% in Jigong Neodeol. Both areas had low wind speeds, with maxima of 5 m/s in Ipseok-dae and 3 m/s in Jigong Neodeol. As a result, it is evaluated that crack behavior in Ipseok-dae columnar joints and Jigong Neodeol rock blocks have maintained a very stable state so far. The surface temperature, temperature, relative humidity, and wind velocity of the two areas showed small difference depending on the season, indicating that they were affected to some extent by the season. From a long-term perspective, this can continuously affect the deformation of the Ipseok-dae columnar joints or Jigong Neodeol rock blocks. Therefore, in order to accurately evaluate their stability, it is considered that the current microscopic delamination and exfoliation or the propagation and expansion of cracks should be continuously measured.

A Short Note on 3-Dimensional Slope Stability Analysis (3차원 사면안정해석에 관한 소고)

  • 서용석;윤운상
    • The Journal of Engineering Geology
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    • v.14 no.2
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    • pp.235-241
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    • 2004
  • 사면활동은 삼차원적인 토괴 혹은 암괴의 입체적 움직임의 산물이며 여러 가지 복잡한 지질학적 요인에 의하여 발생하고 있다. 하지만 사면안정해석은 일반적으로 이차원적으로 수행됨으로써 해석모델을 극히 단순화시키고 있다.(중략)

Spatial pattern and surface exposure ages of cryoplanation surface at Mt. Moodeung (무등산 평활사면(cryoplanation surface)의 형성시기와 분포특성)

  • OH, Jong Joo;PARK, Seoung-Phil;SEONG, Yeong Bae
    • Journal of The Geomorphological Association of Korea
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    • v.19 no.1
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    • pp.83-97
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    • 2012
  • Slopes of Seoseokdea~ Jangbuljae, at Mt. Moodeung, appears repeatedly the cliffs are mostly greater than $70^{\circ}$, and the planations maintain around $5^{\circ}$ in general. They studied the creation of development environments, cryoplanation are mainly facing the southwest. It is assumed that rock falling had been wostly occurred under a periglacial environment through jointing due to repeated freezing and thawing. Planation at the bottom of Columnar joint are described structural benches. Movement precesses of planation matrix are solifluction or jelifluction. The result of age determination of the slopes in Jangbuljae tells that the upper part of Ibseokdae has been remaining exposed to the land surface from 110,000 year ago. The blocks in the bottom part has been exposed to the surface around 10,000 year ago while Jangbuljae has been exposed to the surface about 50,000 year ago. It was assumed that they moved to the current location since being separated from columnar joint after exposure to the surface.

Changes in Distribution of Debris Slopes and Vegetation Characteristics in Mudeungsan National Park (무등산국립공원의 암설사면 분포변화 및 식생 특성)

  • Seok-Gon Park;Dong-Hyo Kim
    • Korean Journal of Environment and Ecology
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    • v.37 no.1
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    • pp.1-12
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    • 2023
  • We analyzed the distribution area of debris slopes in Mudeungsan (Mt. Mudeung) National Park by comparing aerial photos of the past (1966) and the present (2017) and identified the vegetation characteristics that affect the change in the area of the debris slopes by investigating the vegetation status of the debris slopes and the surrounding areas. The area of debris slopes in Mt. Mudeung appears to have been reduced to a quarter of what it used to be. Debris slopes here have decreased at an average rate of 2.3 ha/yr over 51 years by vegetation covers. Notably, most of the small-area debris slopes in the low-inclination slopes disappeared due to active vegetation coverage. However, there are still west-facing, south-west-facing, south-facing, and large-area debris slopes remaining because the sun's radiant heat rapidly raises the surface temperature of rock blocks and dries moisture, making tree growth unfavorable. Because of these locational characteristics, the small-scale vegetation in the middle of Deoksan Stony Slope, which is the broadest area, showed distinct characteristics from the adjacent forest areas. Sunny places and tree species with excellent drying resistance were observed frequently in Deoksan Stony Slope. However, tree species with high hygropreference that grow well in valleys with good soil conditions also prevailed. In some of these places, the soil layer has been well developed due to the accumulation of fine materials and organic matter between the crevices of the rock blocks, which is likely to have provided favorable conditions for such tree species to settle and grow. At the top of Mt. Mudeung, on the other hand, the forest covered the debris slopes, where Mongolian oaks (Quercus mongolica) and royal azaleas (Rhododendron schlippenbachii), which typically grow in the highlands, prevailed. This area was considered favorable for the development of vegetation for the highlands because the density of rock blocks was lower than in Deoksan Stony Slope, and the soil was exposed. Moreover, ash trees (Fraxinus rhynchophylla) and Korean maple trees (Acer pseudosieboldianum) that commonly appear in the valley areas were dominant here. It is probably due to the increased moisture content in the soil, which resulted from creating a depressive landform with a concave shape that is easy to collect rainwater as rock blocks in some areas fell and piled up in the lower region. In conclusion, the area, density of the rock blocks, and distribution pattern of rock block slopes would have affected the vegetation development and species composition in the debris slope landform.

A Study on Bounce Height and Impact Energy Considering Slope Height, Rockfall Weight Using Rockfall Program Considering Slope Height, Rockfall Weight (낙석해석프로그램을 이용한 비탈면 높이, 낙석중량별 도약높이 및 충격에너지 검토)

  • You, Byung-Ok;Han, Won-Jun;Lee, Sang-Duk;Shim, Jea-Won
    • Journal of the Korean GEO-environmental Society
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    • v.12 no.3
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    • pp.47-54
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    • 2011
  • The rockfall protection fence installed to secure safety against rockfall occurring in cut slope has been designed under the condition with 50kJ of impact energy arising when the 400kg of rock block is falling from 12.5m height. However, in falling case of bigger rock block or from higher place, it is hard to be secure of safety with existing rockfall protection fence. Using the rockfall program, safety analysis for rockfall is conducted in this paper by changing slope height, separating distance from fence, and slope angle, according to rock block sizes. In the result of analysis, when a 400kg of rock block which is designed load is fallen, the existing rockfall protection fence with 2.5m height can secure most of rock fall except some cases for the slope having 20m or less hight, whereas for more than 20m height, the fallen rock is frequently splattered over the rockfall protection fence, as well as the impact energy of rockfall may exceed designed impact energy. Therefore, in the design of rock fence, it is considered appropriate to design that after conducting safety review for rockfall according to the ground conditions, evaluating the bounce height and impact energy of rock fall, and then installing appropriate rockfall protection fence would be applicable rather than just following standards based design drawing.

A study on landforms in Gosung, Gangwon province (강원도 고성 일대의 지형 경관에 대한 연구)

  • Kim, Jong Yeon
    • Journal of The Geomorphological Association of Korea
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    • v.18 no.3
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    • pp.65-81
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    • 2011
  • The landforms based on granite and basalt in Gosung, Gangwon province were analysed. Some part of this area experienced volcanic activities while most of the area was experiencing erosion of weathered mantle(saprolites) of mesoic granites during cenozoic period. Two different lithologies affect the mode of landscape evolution. The basalt covers the mountain tops as a 'cap rock' with flat surfaces. It shows relatively fresh rock surface with cliff or steep slops at the boundary with weathered granite. The blocks detached from the cliff accumulated at the foot of the cliff(talus) or moved and filled the valley(block streams). These debris slopes cover the deeply weathered granites. In the case of Oeum Mt. and Duibaekjae, the number of point of origin of the basalt flow is not clear. The orientation of blocks from block stream coincides with slope aspects and it can be assumed that the bolcks were moved by solifluction. The landscape change of the block streams are dominated by removal of weathered material from beneath of the valley rather than removal of bedrock blocks themselves.

Structural Stability, Weathering and Conservation Method of Granite Standing Sculptured Buddha at Hwangsang-dong, Kumi (구미 황상동 마애여래입상의 구조적 안정성, 풍화 및 보존방안)

  • Lee, Chan Hee;Choi, Suck Won;Suh, Mancheol;Chae, Sang Jeong
    • Journal of Conservation Science
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    • v.9 no.1
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    • pp.21-32
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    • 2000
  • Rock composition of the Hwangsang-dong Granite Standing Sculptured Buddha (Treasure No. 1122) in the Kumi City is biotite-hornblende granodiorite which consists of about 30 pieces of individual rock blocks of same compositions. However, the cap rocks is pebble-bearing coarse sandstone. Rock blocks of the Standing Buddha and surrounding out crops occur well developed several joint systems of $N25^{\circ}$ to $45^{\circ}W$ strike and nearly vertical (70 to $85^{\circ}SE$) dipping. Rock blocks of the Standing Buddha showed vertical, horizontal and oblique joints, and those blocks are well supported by individual blocks. However, the junction part of the blocks are under dangerous situation due 10 seriously mechanical and chemical weathering. Host rock of the Standing Buddha belongs to the HW grade, therefore mostly rock-forming minerals of the granodiorite Standing Buddha altered with clay and iron hydroxide minerals by mineralogical and chemical weathering. Near surface of the Standing Buddha show spore and mycelium of green algaes, and a joint plane alive with weeds. We suggest that if structural stability for the Standing Buddha remove essentially a unstable rock blocks from the main body, and the main body necessitate supporting by rock bolting method because of repeated unstability and minimizing stress to the rock blocks. For the opened joint planes, fractured surface and alive weeds will attempt to fill in a petro-epoxy, petro-filler and biochemical treatments for the algaes, and ground water curtain and wall seems to be necessary for water flow and diminishing humidity of the Standing Buddha.

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