• Title/Summary/Keyword: 추가령 구조곡

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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
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    • v.51 no.4
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    • pp.473-490
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    • 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.

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The Geodynamic Evolution of the Chugaryeong Fault Valley in a View Point of Paleomagnetism (고지자기학적 관점에서 본 추가령단층곡의 생성과 진화)

  • 이윤수;민경덕;황재하
    • Economic and Environmental Geology
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    • v.34 no.6
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    • pp.555-571
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    • 2001
  • The dynamic evolution of the Chugaryeong fault valley is studied by paleomagnetic works on 163 samples at 16 sites from Late Cretaceous and Quaternary volcanic rocks in the valley. Conglomerate test and stepwised thermal/alternating field demagnetization indicate that all the characteristic directions are of primary origin. Paleomagnetic pole ponsition(216.8$^{\circ}$E/7l .6$^{\circ}$N; dp=7.1$^{\circ}$, dm=10.0$^{\circ}$) for the upper par of the Jijangbong Volcanic Complex Is indistinguishable from the coeval retference pole position from the Gyeongsang Basin, which further substanciates the reliability of the Paleomagnetic data. This indicates the study area has not undergone any tectonic rotation since Late Cretaceous by uy significant reactivation of the Chugaryeong fault valley. The Quaternary pole position (134.2$^{\circ}$E/86.5$^{\circ}$N; $A_{95}$=7.1 $^{\circ}$) from the Jeongog Basalt reflects the present geocentric axial dipole field for the area, supporting the above conclusion. Unlike the upper part, paleomasnelic directions of the lower part of the Jijangbong Volcanic Complex show random distrinution between sites. We interpret that the early stage of the volcanic activity was created by sinistral strike slip motion of the Chugaryeong fault during early Late Cretaceous. The creation and evolution of the Chugaryeong fault valley emphasize the significance of the kinematic FR (folding ruler) model in east Asia.

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서울.경기 지역의 지질 및 지반특성

  • 김명모
    • Proceedings of the Korean Geotechical Society Conference
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    • 2004.03a
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    • pp.176-187
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    • 2004
  • 서울ㆍ경기지역은 한반도의 서부중앙지역으로 동경 126$^{\circ}$와 127$^{\circ}$, 북위 36$^{\circ}$와 38$^{\circ}$ 사이에 위치해 있으며, 면적은 서울 605$\textrm{km}^2$, 경기도 10,184$\textrm{km}^2$를 차지한다. 북쪽으로는 휴전선, 서쪽으로는 서해, 동쪽으로는 강원도, 남쪽으로는 충청도와 접하고 있으며 한강에 의해 남북지역으로 나뉘어져 한 수 이북은 산간지역이 한 수 이남지역에는 평야지대가 발달하고 있다. 지형은 대체로 추가령 구조곡을 경계로 북부산지와 남부산지로 나누어지는데, 북부는 중국 요동방향의 마식령산맥, 남부는 중국방향의 광주산맥과 차령산맥이 각각 그 골간을 이루고 있으며, 서쪽해안에 가까워질수록 고도가 낮아져 평야나 구릉성 산지로 바뀐다.(중략)

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우리 나라 동굴의 지질과 환경 보전

  • 정창희
    • Proceedings of the Speleological Society Conference
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    • 1996.09a
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    • pp.64-64
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    • 1996
  • 석회동굴은 카르스트 지형 지역에서 지하 형성물로 나타나는 공동지역으로, 이 공동화된 공간에 2차적으로 석순, 석주, 종유석 등이 침전되어 생긴 동굴이다. 이런 카르스트 지형은 석회암 지층에서 용식작용으로 생겨나는데, 우리나라에서는 북쪽은 평안남도 동반지역과 함경남도의 남부서경지역, 황해도 서남부, 그리고 강원도 남부지역, 추가령 구조곡의 일부들이 해당한다. 그리고 남쪽은 문경 - 단양 - 제천 - 영월 - 평창 - 정선 - 삼척 - 강릉에 걸친 지역들이다. 따라서 우리나라의 석회암동굴들은 그 대부분이 조선계 대석회암통의 막동 석회암 층에 분포되고 있다.(중략)

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Formative Age and Process on Basalt of Lava Plateau in the Cheolwon and Yeoncheon Areas, Central Korea (철원 및 연천 지역 용암대지 현무암의 형성 시기 및 형성 과정)

  • Lee, Min-Boo;Seong, Yeong Bae;Lee, Gwang-Ryul
    • Journal of The Geomorphological Association of Korea
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    • v.27 no.4
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    • pp.41-51
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    • 2020
  • The Cheolwon-Pyeonggang Lava Plateau on the Chugaryeong tectonic valley is one of the most extensive volcanic areas in central Korea. However, formative age and process of the plateau still remains a controversial issue. This study presented OSL ages on the upper and lower sedimentary layers of basalt from four sites in the Cheolwon and Yeoncheon areas and estimated age and process of plateau formation based on sedimentary- and chrono-stratigraphy and topographic analysis. The results suggested that most of the initial topography of the plateau on the Cheolwon and Yeoncheon areas had been almost completed before approximately 90 ka. However, the last lava flow around Jangheung-ri, Cheolwon, seemed to occur until 20-30 ka and had led to complete the present plateau, while the last lava flow in the Jeongok area, Yeoncheon, was estimated to occur at approximately 40 ka.

Investigation of Post-seismic Sites Using Local Seismic Tomography in the Korean Peninsula (지진 토모그래피를 이용한 한반도의 과거진원지역의 특성 연구)

  • Kim So-Gu;Bae Hyung-Sub
    • Economic and Environmental Geology
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    • v.39 no.2 s.177
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    • pp.111-128
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    • 2006
  • Three dimensional crustal structure and source features of earthquake hypocenters on the Korean peninsula were investigated using P and S-wave travel time tomography. The main goal of this research was to find Vp/Vs anomalies at earthquake hypocenters as well as those of crustal structure of basins and deep tectonic settings. This allowed fer the extrapolation of more detailed seismotectonic force from the Korean peninsula. The earthquake hypocenters were found to have high Vp/Vs ratio discrepancies (VRD) at the vertical sections. High V/p/Vs ratios were also found in the sedimentary basins and beneath the Chugaryong Rift Zone (CRZ), which was due to mantle plume that subsequently solidified with many fractures and faults which were saturated with connate water. The hypocenters of most earthquakes were found in the upper crust for Youngwol (YE), Kyongju (KE), Hongsung (HE), Kaesong (KSE), Daekwan (DKE), and Daehung (DHE) earthquakes, but near the subcrust or the Moho Discontinuity for Mt. Songni (SE), Sariwon (SRE) and Mt. Jiri (JE) earthquakes. Especially, we found hot springs of the Daekwan, Daehung and Unsan regions coincide with high VRD. Also, this cannot rule out the possibility that there are some partial meltings in the subcrust of this region. High VRD might indicate that many faults and fractures with connate water were dehydrated when earthquakes took place, reducing shear modulus in the hypocenter areas. This is can be explained by due to the fact that a point source which is represented by the moment tensor that may involve changes in volume, shear fracture, and rigidity. High Vp/Vs ratio discrepancies (VRD) were also found beneath Mt. Backdu beneath 40 km, indicating that magma chamber existed beneath Mt. Backdu is reducing shear modulus of S-wave velocity.