• Proceedings of the KSEEG Conference
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• 2000.04a
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• pp.107-108
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• 2000

• Economic and Environmental Geology
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• v.47 no.1
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• pp.29-38
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• 2014

Recently developed illite-age-analysis (IAA) approach has been applied to determine the multiple events for the Singal and Wangsukcheon faults in the Chugaryeong fault belt, Korea. Fault reactivated events during Late Cretaceous to Paleogene events($69.2{\pm}0.3$ Ma and $27.2{\pm}0.5$ Ma) for the Singal fault and of $75.4{\pm}0.8$ Ma for the Wangsukcheon fault were determined by combined approach of the optimized illite-polytype quantification and the K-Ar age-dating of clay fractions separated from the fault clays. These absolute geochronological determinations of the multiple tectonic events recorded in the Chugaryeong fault belt are crucial to establish the tectonic evolution of the Korean Peninsula since Late Cretaceous.

• Economic and Environmental Geology
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• v.57 no.1
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• pp.73-81
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• 2024

To estimate the tectonic displacement of the Chugaryeong Fault System (CFS), gravity surveys were conducted along the Dongducheon fault (DF) and the Wangsukcheon fault (WF). A total of 1,100 stations for the DF and WF regions have been added to the current gravity database. The results of the gravity interpretation indicate that (1) the dextral displacement of the DF is about 3,000 m, similar to the tectonic displacement (2,900-3,100 m) shown in the geological map. (2) The dextral displacement of the WF is about 3,200 m. (3) Taken together, the tectonic displacement of the CFS is estimated to be about 3,000 m on average. To investigate more accurate tectonic displacement of the CFS, further gravity surveys is planned for the Pocheon fault, Gyeonggang fault, and Inje fault.

• 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.

• Proceedings of the KGS Conference
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• 2001.12a
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• pp.103-107
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• 2001

• Proceedings of the KSEEG Conference
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• 2001.04a
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• pp.160-162
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• 2001

• Proceedings of the KGS Conference
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• 2001.05a
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• pp.117-121
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• 2001

• 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.

• Proceedings of the KSEEG Conference
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• 2003.04a
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• pp.131-134
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• 2003

계기지진기록에 의하면, 한반도에서는 중국이나 일본만큼 지진발생빈도가 높거나 강진은 없으나, 북한에서는 추가령단층대 이서지역, 남한에서는 아산만～영일만 일원을 따라 대상으로 분포한다. 역사지진기록에 의하면, 경주시 주변에서 8개의 큰 지진이 일어났으며, 이중 779년에 일어난 경주지진에서는 백명 이상의 사상자가 발생한 기록이 있다고 하였다(경재복, 1997). (중략)

• Economic and Environmental Geology
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• v.54 no.6
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• pp.743-752
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• 2021

The three-dimensional distribution of the fault was evaluated using gravity field interpretation such as curvature analysis and Euler deconvolution in the Seoul-Gyeonggi region where the Chugaryeong fault zone was developed. In addition, earthquakes that occurred after 2000 and the location of faults were compared. In Bouguer anomaly of Chugaryeong faults, the Pocheon Fault is an approximately 100 km fault that is extended from the northern part of Gyeonggi Province to the west coast through the central part of Seoul. Considering the frequency of epicenters is high, there is a possibility of an active fault. The Wangsukcheon Fault is divided into the northeast and southwest parts of Seoul, but it shows that the fault is connected underground in the bouguer anomaly. The magnitude 3.0 earthquake that occurred in Siheung city in 2010 occurred in an anticipated fault (aF) that developed in the north-south direction. In the western region of the Dongducheon Fault (≒5,500 m), the density boundary of the rock mass is deeper than that in the eastern region (≒4,000 m), suggesting that the tectonic movements of the western and eastern regions of the Dongducheon Fault is different. The maximum depth of the fracture zone developed in the Dongducheon Fault is about 6,500 m, and it is the deepest in the research area. It is estimated that the fracture zone extends to a depth of about 6,000 m for the Pocheon Fault, about 5,000 m for the Wangsukcheon Fault, and about 6,000 m for the Gyeonggang Fault.