• Title/Summary/Keyword: 용암대지

Search Result 36, Processing Time 0.02 seconds

오대연지의 화산호 풍경

  • 원일평
    • Proceedings of the Speleological Society Conference
    • /
    • 1997.10a
    • /
    • pp.91-94
    • /
    • 1997
  • 오대연지는 중국 흑룡강성의 덕도현 경내에 자리잡고 있는 화산지역이다. 본 지역에는 제4기이래에 형성된 화산들이 많이 분포되어 있는데 그 중심 부위에는 구슬 모양으로 된 다섯 개 못이 있기에 오대연지라 한다. 본 지역의 면적은 약 800$km^2$가 되는데 지형상에서는 주로 화산추와 용암대지로 이루어져 있다. 화산의 형성시대가 다르고 자연경관이 전형적이기 때문에 국내외에서 자연적인 화산박물관으로 널리 알려져 있다.(중략)

  • PDF

오대연지의 화산호 풍경

  • 임철호
    • Journal of the Speleological Society of Korea
    • /
    • v.36 no.37
    • /
    • pp.114-117
    • /
    • 1994
  • 오대연지는 중국 흑룡강성의 덕도현 경내에 자리잡고 있는 화산지역이다. 본 지역에는 제4기 이래에 형성된 화산들이 많이 분포되어 있는데 그 중심부위에는 구슬 모양으로 된 다섯개 못이 있기에 오대연지라 한다. 본 지역의 면적은 약800$\textrm{km}^2$가 되는데 지형상에서는 주로 화산추와 용암대지로 이루어져 있다. 화산의 형성시대가 다르고 자연경관이 전형적이기 때문에 국내외에서 자연적인 화산박물관으로 널리 알려져 있다.(중략)

  • PDF

Granite Landforms in the Vicinity of Seungil-gyo Bridge at Cheorwon, Central Korea (철원군 승일교 인근의 화강암 지형 경관)

  • LEE, Min-Boo;HAN, Joo-Yup;KIM, Chang-Hwan
    • Journal of The Geomorphological Association of Korea
    • /
    • v.19 no.4
    • /
    • pp.27-37
    • /
    • 2012
  • This study investigated granite landforms formed by Hantan-gang fluvial erosion and deposition, or by weathering in the area neighboring the Seungil-gyo bridge in Cheorwon-gun Gangwon-do Korea, in which the contact zone of Myeongseongsan granite and Cheorwon lava plateau creates a unique landform. Major granite landforms are deeply weathered hill, sheet erosional landform, paleo-landform surface and paleosoil, micro-fluvial landforms such as pothole and groove, granite rampart, sand bar and boulder bar, former riverbed. And river cliffs on a weakly weathered dome act as a barrier to lateral shifting of the river.

Geomorphological Processes of Jaein Waterfall and Dissection Valley in Hantangang Lava Plateau, Central Korea (한탄강 용암대지의 재인폭포와 개석곡의 지형 형성)

  • Lee, Min-Boo;Lee, Gwang-Ryul
    • Journal of The Geomorphological Association of Korea
    • /
    • v.24 no.3
    • /
    • pp.47-59
    • /
    • 2017
  • This study aims to analyze geomorphologically Jaein Falls in Hantangang Lava Plateau for the landform structure, landform classification, falls dissection and recession. The height and recession length of the Falls are approximately 18m and 340m. after dissection valley arrive at area of the Jijangbong Volcanic Rock Complex of Mesozoic era, the fall will disappear. The structure of the dissection valley shows totally well vertical columnar joint near falls and plunge pool, colluvial talus deposits toward lower reach by the freezing-thawing and wet-dry activities, and alluvial cone and delta in estuary to Hantangang River. The Falls' age date and recession rate in the valley maybe relate to the age of the lava plateau. The estimated recession rate of the fall should be 8.75m/ka to 2.3m/ka, depending on the age 500ka to 40ka in lava plateau.

Stratigraphic Analysis on Paleofluvial Outcrop underJeongok Basalt Layer in the Chugaryeong Rift Valley, Central Korea (추가령 열곡 내 전곡 현무암층 하부 고하성층 노두 층서 분석)

  • Lee, Min-Boo;Lee, Gwang-Ryul
    • Journal of The Geomorphological Association of Korea
    • /
    • v.20 no.3
    • /
    • pp.55-63
    • /
    • 2013
  • The study deals with the geochemical analyses on the stratigraphy and sedimentation of the paleofluvial outcrop under Jeongok basalt layer in Chugaryeong Rift Valley. The results of field survey and analysis show that the paleofluvial sand and gravel layers had been constructed before the arrival of basaltic lava in Jeongok area of Hantan River valley in central Korea. XRF, for the main elements analysis, results present that JG2-3, a test sample from basalt weathering layer, has different characteristics from 5 other samples in the aspects of chemical weathering levels. ICP-MS, for analysis of the rare earth elements analysis, estimates that gravel layer, in the lowest part of the outcrop, had been originated from pre-lava bedrocks near the upper reach of the Hantan River, so the layer is almost not related to basalt layers. Finally, the OSL dating results in paleofluvial sedimentation had been in process until nearly 40,000 BP, before formation of lava plateau in the Jeongok area.

Quaternary Geology and Paleoecology of Hominid Occupation of Imjin Basin (임진강유역 구석기 공작의 고생태학적 배경)

  • Seonbok Yi
    • The Korean Journal of Quaternary Research
    • /
    • v.2 no.1
    • /
    • pp.25-50
    • /
    • 1988
  • The survival of rich evidence of palaeolithic occupation found in the Imjin-Hant'an River basin was possible due to many fortuitous geological conditions provided there. Formation of the basalt plain in a narrow valley system which developed during the late Mesozoic insured the appearance of a basin of sedimentation in which archaeological sites would be preserved with relatively minor post-depositional disturbance. Geomagnetic and K-Ar dating indicates that lava flows occurred during the Brunes Normal Epoch. During and after the process of basin sedimentation, erosion of the plain was confined to the major channel of the present river system which developed along the structural joints formed by the lava flow. Due to characteristic columnar structure and platy cleavage of the basalt bedrock, erosion of the basalt bedrock occurred mainly in vertical direction, developing deep but narrow entrenched valleys cut into the bedrock. Consequently, the large portion of the site area remained intact. Cultural deposits formed on top of the basalt plain were left unmodified by later fluvial disturbances due to changes in the Hant'an River base-level, since they were formed about 20 to 40m above the modern floodplain. Sedimentological evidence of cultural deposits and palynological analysis of lacustrine bed formed in the tributary basin of the Hant'an River indicate that hominid occupation occurred in this basin under rapidly deteriorating climatic conditions. From three thermoluminescence dates, the timing of hominid occupation as represented by 'Acheulian-like' bifaces apparently occur sometime during 45,000 BP. Thus, deposition of cultural layers in this basin approximately coincides with the beginning of the second stadial of the final glacial, during which the Korean Peninsula must have had provided a sanctuary for prolonged human occupation.

  • PDF

A Study of Regional Geomorphology in the Chugaryeong Tectonic Valley, Central Korea (추가령 구조곡의 지역지형 연구)

  • Lee, Min-Boo;Lee, Gwang-Ryul
    • Journal of the Korean Geographical Society
    • /
    • v.51 no.4
    • /
    • pp.473-490
    • /
    • 2016
  • This study aims to analyze the regional geomorphology of the Chugaryeong Tectonic Valley which has been one of the most important areas for Korean geomorphological research. Though the Chugaryeong Tectonic Valley has been thought important for the tectonic settings and orographic processes in Korea, geomorphological and geological discussions still are sustaining for finding out evidences of the settings. The Chugaryeong valley region has many geomorphic themes such as tectonic structure, volcanics, river, mountain, terrace, lake and sediment layers. The research of the valley focuses on the comprehensive analysis of the previous references mainly including geomorphic naming, geomorphology and geology, and history of the study for estimating the origin of tectonic valley, formation of the lave plateau, change of river structure by dissection, restoration of the landform before lava eruption, and the processes and age dating of the various landforms. Conclusively, the Chugaryeong Tectonic Valley may be recognized as the linear region of the tectonic and volcanic landforms with other various applied geomorphic settings.

  • PDF

A Study on the Distribution and Change of Montane Meadows in the East Face of Mt. Baekdu (백두산 동사면 산지초지 분포와 변화에 관한 연구)

  • Kim, Nam-Sin
    • Journal of the Korean association of regional geographers
    • /
    • v.18 no.4
    • /
    • pp.364-373
    • /
    • 2012
  • This study is to analyze distribution and change of montane meadows on the lava plateau in the east face of Mt. Baekdu. Process for aims carried out field survey, and analyzed landsat images of 1993, 1999, 2004, and year 2010. After research findings, the area of forests has increased by 33% from $636km^2$ to $848km^2$, montane meadow has decreased by 58% from $303km^2$ to $127km^2$ during 18 years. Montane meadows could be classified as 2 categories of wet meadow and dry meadow by the geomorphic environments and vegetation types. Wet meadow has decreased by 30%, dry meadow has decreased by 70% in the same period. Decreasing areas are replacing meadows with forests in invasion by trees and shrubs. According to the analysis with weather data for 16 years from 1993 to 2008, temperature has increased by $1.6^{\circ}C$, on the other hand, precipitation has decreased by 5.3mm. These kinds of climate change trends continue in the future, it could be change montane meadows into tree types.

  • PDF

Volcanic Processes of Dangsanbong Volcano, Cheju Island (제주도 당산봉 화산의 화산과정)

  • 황상구
    • The Journal of the Petrological Society of Korea
    • /
    • v.7 no.1
    • /
    • pp.1-14
    • /
    • 1998
  • Dangsanbong volcano, which is located on the coast of the western promontory of Cheju Island, occurs in such a regular pattern on the sequences which represent an excellent example of an eruptive cycle. The volcano comprises a horseshoe-shaped tuff cone and a younger nested cinder cone on the crater floor, which are overlain by a lava cap at the top of the cinder cone, and wide lava plateau in the moat between two cones and in the northern part. The volcanic sequences suggest volcanic processes that start with Surtseyan eruption, progress through Strombolian eruption and end with Hawaiian eruption, and then are followed by rock fall from sea cliff of the tuff cone and by air fall from another crater. It is thought that the eruptive environments of the tuff cone could be mainly emergent because the present cone is located on the coast, and standing body of sea water could play a great role. It is thought that the now emergent part of the tuff cone was costructed subaerially because there is no evidence of marine reworking. The emergent tuff cone is characterized by distinctive steam-explosivity that results primarily from a bulk interaction between rapidly ascending magma and external water. The sea water gets into the vent by flooding accross or through the top or breach of northern tephra cone. Dangsanbong tuff cone was constructed from Surtseyan eruption which went into with tephra finger jetting explosion in the early stage, late interspersed with continuous upruch activities, and from ultra-Surtseyan jetting explosions producting base surges in the last. When the enclosure of the vent by a long-lived tephra barrier would prevent the flooding and thus allow the vent to dry out, the phreatomagmatic activities ceased to transmit into magmatic activity of Strombolian eruption, which constructed a cinder cone on the crater floor of the tuff cone Strombolian eruption ceased when magma in the conduit gradually became depleted in gas. In the Dangsanbong volcano, the last magmatic activity was Hawaiian eruption which went into with foundation and effusion of basalt lava.

  • PDF