• Journal of the Korean Geographical Society
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• v.42 no.3 s.120
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• pp.388-404
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• 2007

This study interprets evolution of fluvial terraces along the four Yeongdong- and Yeongseo streams such as Naerin River, Yeongok River, Golji River and Osip River, in Gangwon Province based on the tectonics. The results from the analyses of the distribution pattern of fluvial terraces and incision rates of rivers show distinctively the evidence as the axis of uplift by Taebaek Mountains, especially on the 4th, 5th and 6th terraces in upper reach of Osip River among the four streams. The axis of uplift extends to the zone of $30\sim40km$ in width as well as the divide. The difference of uplift between upper and middle reaches of Naerin River and total reach of Golji River wasn't found from the height from riverbed by the active uplifting along all reaches, estimated to be set in inner area of uplift zone. Incision rate of period between formation age of 2nd terrace and 1st terrace is calculated $0.13\sim0.22m/ka$, and incision rate of period between formation age of 1st terrace and Present is diversely calculated $0.17\sim0.27m/ka$ by the climatic discrepancy between the two periods. The incision rate of Yeongdong streams whose mouths reach to the sea level eroded actively more than Yeongseo streams in the uplift zone. And Yeongdong streams between formation age of 1th terrace and present appears to much higher than that of Yeongseo streams, due to active down-cutting in oder to balance against the sea level.

• Journal of The Geomorphological Association of Korea
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• v.24 no.3
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• pp.1-11
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• 2017

The pollen analysis on the deposits of the lower marine terrace I of the estimated paleoshoreline height of 18m was performed in order to estimate the formation age of this terrace developed at the Sanha-dong coast, Ulsan, southeastern coast of the Korean peninsula. The pollen assemblage of the peat layer of SH-1 pollen zone (Quercus-Ulmus/Zelkova zone), lying directly on the marine rounded pebble layer of this terrace, shows that the climatic environment of the deposition period of SH-1 pollen zone was almost similar to that of the Postglacial climatic optimum period, but slightly cooler than that of the late warm stage of Last Interglacial(MIS 5a) in the eastern coast of Korea. This heightens the possibility that the deposition period of the marine rounded pebble layer which was covered by the above SH-1 peat layer is the MIS 5e which has been estimated by a previous study of the sedimentary facies of this terrace deposits (Choi, 2016). The pollen assemblage of SH-2 pollen zone (Pinus-Quercus zone) shows that the climate of this period was almost similar to that of the late Postglacial, but slightly cooler than that of the period of SH-1 pollen zone. This means that the climate around the Sanha-dong was still warmer in the deposition period of the peat layer of SH-2 pollen zone. Thus, the peat layer of SH-2 pollen zone was considered to have been deposited during the period from the early regression stage of the MIS 5d which is the estimated final stage in the deposition period of the above peat layer of SH-1 pollen zone to any stage in which the warmer environment of MIS 5 has still lasted. The humic silt layer of SH-3 pollen zone (Pinus-Ulmus/Zelkova-Abies zone) is assumed to have been deposited during the interstadial of the Last Glacial (MIS 3).

• The Journal of the Petrological Society of Korea
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• v.23 no.3
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• pp.187-195
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• 2014

In this paper, we report new OSL ages of the marine terrace sediments at Suryum fault site, using single grains of quartz, and briefly discuss their chronological implications on the timing of terrace formation along the southeastern coast of Korea. Of 1200 grains measured, 93 quartz grains were found to have OSL properties suitable for dating, the equivalent dose ($D_e$) values of which varied significantly, ranging from 50 Gy to 610 Gy with the overdispersion of $30{\pm}4%$. Applied to the Central Age Model (CAM) and Minimum Age Model (MAM), these quartz grains showed the OSL ages of $83{\pm}4ka$ and $60^{+3}{_{-7}}ka$, respectively, both of which are stratigraphically inconsistent with the previously reported OSL ages of lower $2^{nd}$ terrace (MIS 5a; ~80 ka). However, Finite Mixture Model (FMM) revealed that a small fraction of the measured quartz grains ($6{\pm}4%$) were of the ages ($194{\pm}24ka$) corresponding to MIS 7. Conclusively, based on single grain OSL ages, it would be prudent not to exclude the possibility that the marine terrace sediments at Suryum fault site have formed during MIS 7. Further, our single grain OSL ages imply that multiple grain(single aliquot) OSL dating methods are not applicable to the marine sediments at Suryum fault site.

• Korean Architects
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• s.603
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• pp.18-23
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• 2019

• Korean Architects
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• s.603
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• pp.24-25
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• 2019

• Korean Architects
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• s.642
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• pp.52-57
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• 2022

• Journal of the Korean Geophysical Society
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• v.2 no.3
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• pp.155-168
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• 1999

The paleoseismological importance of the Yangsan fault zone was examined by historical earthquake data, aerial photograph, and trench survey of the area. Occurrences of great earthquakes during the historical time indicate that the Yangsan and/or Ulsan fault have been active during the late Quaternary and generated historical events. Geomorphological evidences of the recent fault activity are clearly shown both in the northern segment (Yugye-ri, Tosung-ri and Naengsu-ri areas) and in the southern segment (Eonyang to Tongdosa areas) of the Yangsan fault. The main Yangsan fault is characterized by fault gouges and NNE-SSW lineaments. The reverse faulting in the Yugye-ri area generated about three-mater displacement of the lower terrace deposits. On the other hand, a major strike-slip movement with a minor component of 5-12 m vertical displacement was identified by the offset of the higher terrace surface in the Eonyang area.

• Journal of The Geomorphological Association of Korea
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• v.19 no.3
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• pp.97-108
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• 2012

During the last few decades, the ever-increasing knowledge of coastal morphogenic processes has made marine terraces the most recognizable, widespread and scientifically reliable records to determine both qualitatively and quantitatively the vertical movements that have affected the tectonically active coastal regions during the Quaternary. This study first aims to address the marine terrace records from Suje-ri to Suryum-ri along the coast of Gyeongju, SE Korea. Eight distinct flights of terraces, including HH YC, elevated up to 160 m above present sea level have been mapped along the coast of the study areas, and are designated $L_{II}$ to HH YC from the youngest to oldest. Based on the elevation of paleo-shoreline and inferred formation age for HH YC uplift rate since the middle Pleistocene has been estimated at 0.23 mm/year. Establishing the nature and timing of the uplift history derived from marine terraces provide a better understanding of neotectonic framework for explain enigmatic, complex landscape evolution in the Korean peninsula.

• Journal of The Geomorphological Association of Korea
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• v.18 no.1
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• pp.101-112
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• 2011

Coastal terrace was developed at 7.2m height near Shinchon village in Geoje Island. It is located on the east side of southern coast in Korean Peninsula, where sea-level changes caused by ebb and flow of the tide, embayment are relatively low. Due to the breccia layer by mass-movement, dark grayish clayey formation, marine origin's rounded gravel are deposited sequentially in a cross-section of coastal terrace, so it provides a good example which understand Holocene sea level changes to determine the effect on the various sedimentary environments. For the purpose of identifying the morphogenetic process, Grain size, Roundness, XRD, AMS dating analysis was attempted. As a result, after last glacial age, Holocene sea level rise to +5.6m(4,740±100yrs BP). At that time, various geomorphological features are considered to be formed.

• Korean Journal of Soil Science and Fertilizer
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• v.19 no.2
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• pp.89-97
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• 1986

To clarify the soil characteristics and genesis of the clayey terrace soils in Yeongnam area, the study were carried out with 9 typifying pedons of toposequential terrace soils in Yeongcheon (inland area) and Yeongil (coastal area) region. The results of soil genesis oriented investigations on soil mineralogical compositions and weathering characteristics were summarized as follows; 1. The contents of heavy minerals contained in sand fraction of the terrace soils were less than 5%, but the content in soil layers considered to be originated from other than terrace deposits had 9.8-16.2%. The content of feldspars in light minerals were higher in Yeongcheon sequence while the Yeongil sequence were characterized by having higher content in quartz. The ratios of quartz/feldspars in the soil layers where expecting lithological discontinuity, were different from that of terrace deposits. 2. The resistate index of maturity ranged around 76.7-29.9 in Yeongcheon area and around 85.6-67.2 in Yeongil area. The indices increased with the elevations of terraces. 3. The molar ratios of $SiO_2/Al_2O_3$ in clay fraction were around 1.93-2.65. The parent materials of the terrace deposits judged by the ratios of $Al_2O_3/TiO_2$ and $Fe_2O_3/Al_2O_3$ were considered to be the felsic materials. 4. The compositions of clay minerals detected by X-ray diffractogram and D.T.A. thermogram were dominated by kaolin and illite with subsidiary minerals of vermiculite, quartz, vermiculite intergrading to illite etc. It was distinguished from terrace deposits that by having higher amount of kaolin and montmorin minerals in the substrata of Bancheon soils in Yeongcheon area and Upyeong soils in Yeongil area, respectively.