• The Korean Journal of Quaternary Research
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• v.18 no.2 s.23
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• pp.1-2
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• 2004

The Ilkwang Fault is NNE-striking, elongated 40 Km between Ulsan and Haendae-ku, Busan in southeastem part of the Korean Peninsula(Kim, D.H. et al., 1989; Kim, J.S. et al., 2003). This paper is mainly concemed about the ages of the fault activities especially in the Quatemary, infered from classification of geomorphic surface and trench excavation for the construction of Singori nuclear power plant. The geomorphi surfaces are classified into the Beach and the Alluvial plain, the 10 m a.s.l. Marine terrace, the 20 m a.s.l. Marine terrace, the Reworked surface of 45 m a.s.l. Marine terrace and the Low relief erosional surface, from lower to higher altitude. The Beach and the Alluvial plain are elongated to the Holocene terrace(ist terrace, choi, 2003). The 10 m a.s.l. Marine terrace is correlated to 2nd terrace (MIS 5em 125 Ka. y. B.P., Choi, 1998). The 45 m a.s.l. Marine terace is correlated to the Lower marine terrace (MIS 7,220 Ka. y. B.P., Choi, 2003 or MIS 9,320 y. B.P.) to the Gwanganri terrace(Penultimate interglacial age, 200-200 Ka. Y. B.P., Oh, 1981). The Low relief erosional surface is distributed coastal side, the Reworked surface of 45 m a.s.l. Marine terrace inland side by the Ilkwang Fault Line as the boundary line. But the former is above 10 m higher in relative height than the latter. The 20 m a.s.l. Marine terrace on the elongation line of the Ilkwang Fault reveals no dislocation. A site was trenched on the straight contract line with $N30^{\circ}$ E-striking between the 10 m a.s.l. Marine terrace and the 20 m a.s.l. Marine terrace. Fault line or dislocation was not observable in the trench excavation. Accordingly, the straight contact line is inferred as the ancient shoreline of the 10 m a.s.l. Marine terrace. The Ages of the Fault activities are inferred after the formation of the Ichonri Formation - before the formation of the 45 m a.s.l. Marine terrace (220 Ka. y. B.P. or 320 Ka. y. B.P.). The Low relief erosional surface was an island above the sea-level during the formation of the 45 m a.s.l. Marine terrace in the paleogeography.

• Journal of The Geomorphological Association of Korea
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• v.25 no.4
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• pp.49-62
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• 2018

This study tries to reveal uplift rates inferred from relative and absolute ages on coastal terrace in the West and South Coasts of South Korea. Uplift rate from relative ages on Pleistocene coastal terrace in the West Coast rangesfrom approximately 0.059 to 0.282 m/ky, while a range of approximately 0.020~0.385 m/ky is calculated from the South Coast, suggesting that the South Coast shows higher rate than the West Coast. Based on absolute ages on coastal terrace during MIS 5 in the South Coast, on the other hand, the uplift rates 1 and 4 have ranges of approximately 0.042~0.062 m/ky and 0.051~0.087 m/ky, respectively, indicating that uplift rate in the South Coast is one-third to one-fourth to that in the East Coast. No research on absolute ages in West Coast terrace and lack of relative and absolute ages in the West and South Coasts are considered as the limit in this study.

• Journal of The Geomorphological Association of Korea
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• v.23 no.2
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• pp.29-45
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• 2016

Chemical composition of fine sediments from Jeongdongjin area are analyzed with XRF method. The results are compared with previously reported results of sandstones of the nearest Simgok port. The weight percentage of $SiO_2$ of the samples are far lower than those of sandstones of Simgok. It is supposed to be happened by the selective elution of $SiO_2$ from the sediment layer of coastal terrace, as there's no evidence of selective input or precipitation of other elements from outside. As a result of chemical alteration or weathering of sediment at coastal terrace, weight percentage of $Al_2O_3$ and $Fe_2O_3$ of samples show far higher values than those of Simgok sandstone. In addition, the relative portion of $Al_2O_3$ and $Fe_2O_3$ are decreased to upward within outcrop of terrace sediment layers. It could be caused by the chemical weathering progress with time. However Chemical Index of alteration(CIA) of sediment samples are no larger than 90 and it could be interpreted that it would take over 100ka for total weathering of sediment in this area. Meanwhile the ratio of $SiO_2/Al2O_3$ of terrace sediment showed as 3.48~6.0 and it is far smaller than those of Simgok sandstones(23.9~49.0). The ratio of $SiO_2/Fe_2O_3$ of terrace sediment(19.19~55.85) showed similar pattern with $SiO_2/Al2O_3$ (Simgok sanstone: 119.6~601.8). The ratios have a weak trend of decreasing upwards within the outcrop, there also a huge difference in value among the samples. Chemical composition of reddish brown and gray layers which suspected as the result of psudogleization reveals that reddish brown parts have higher concentration of $Fe_2O_3$ than other parts, while there was no significant difference in concentration of $Al_2O_3$ and CaO.

• The Korean Journal of Quaternary Research
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• v.17 no.2
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• pp.15-15
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• 2003

In South Korea, marine terraces have been well developed along the eastern coastal zone, and previous researches on the marine terraces have also been focused on to this coastal zone. The marine terraces of the eastern coast of South Korea had been classified into three terrace groups, that is, the higher, middle, and lower surface ones, according to the heights of marine terraces by previous studies(Oh, 1981 ;Chang, 1987 ;Yoon et. al, 1999, 2003 ; Hwang and Yoon, 1996 etc.). Recently, however, it tends to classify the marine terraces based on the concept of geomorphic surface units(Lee, 1987 ; Kim, 1990 ; Choi, S. 2003; Choi S. et. al 2003a,b, etc). For example, it was proposed that the marine terrace surfaces of Eupcheon coast of the southeastern coastal area of Korea could be classified into 16 geomorphic surfaces, i.e., Eupcheon 1terrace(former shoreline height of 160m), 2(153m), 3(140m), 4(130m), 5(124m), 6(115m), 7(100m), 8(92m), 9(82m), 10(71m), 11(62m), 12(53m), 13(43m), 14(35m), 15(18m) and 16(10m) surfaces, in descending order, according to the former shoreline heights(Choi, S, 2003 ; Choi, S. et. al, 2003a,b). Among these terraces, Eupcheon 1, 2, 4, 5 and 7 surfaces had not been reported in previous works. Among the above mentioned marine terraces, Eupcheon 15 terrace, the most widely and continuously distributed marine terrace have been identified as marine terrace of the Last Interglacial culmination period(oxygen isotope stage 5e) which was based on amino acid dates(124∼125ka BP) and geomorphological features such as red soil, pollen analysis, fossil cryogenic structures and crossing terrace concept. Eupoheon 15 terrace surfaces have also been proposed as the key surface for the identification and correlation of the so-called '5e' marine terrace in the eastern coast of South Korea. This terrace was reconfirmed as the Last Interglacial culmination period, which was based on the identification of Ata tephra, one of the wide-spread marker tephra which indicates the Last Interglacial culmination period in Japan by Sasaki et. al(2002). It was thought that marine terraces of the eastern coast of South Korea had been formed by the steady-state uplifting during the Quaternary glacio-eustatic sea level changes(Choi, 1997). The uprift rate of 10cm/1,000years had been proposed in the eastern coast of South Korea based on the former shoreline altitude(18m) of the above Eupcheon 15 terrace. Therefore, it can be estimated that Eupcheon 1 terrace had been formed in the early Pleistocene from the above uprift rate. The OSL dating for the samples of Eupcheon 7, 9, 13, 15 and 16 terraces and identification of marker tephra in the terrace deposits are in progress. It is expected that more elaborate chronology on themarine terraces of the eastern coast of South Korea could be established by these absolute dates and marker-tephra.

• The Korean Journal of Quaternary Research
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• v.7 no.1
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• pp.1-26
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• 1993

The estimation of the Last Interglacial sea level was made by using the thalassostatic terrace which had been developed in the lower reach of Namdaechon river in Kangneung, eastern coastal area of Korea. The fluvial terraces, which have been developed since late Pleistocene, were investigated. The main findings were as follows; 1) That Kangneung terrace I had been formed in the climax period of the Last Interglacial (Oxygen isotope stage 5e) was revealed. It was estimated that Kangneung terrace II had been formed during a certain warmer period between the climax period of the Last Interglacial and the early Last Glacial(probably Oxygen isotope stage 5c or 5a). 2) Being judged from the relative heights of the Kangneung terrace I and II, the sea levels of the formation periods of these terraces were estimated to have been relatively 17~20m and l0m higher than the present sea level, respectively. 3) The formation periods of the Wangsan terrace I and II were supposed to be the early and late Last Glacial respectively, being judged from the following 3 details ; a) the characteristics of the terrace deposits, b) the relation Wangsan terrace II to the buried valley floor, and c) the cross phenomena of the above two terraces to the Kangneung terraces. 4) The formation period of the pseudogleyed red soil in the Kangneung terrace I was estimated to be the middle or late period of the Last Interglacial.

• 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.24 no.4
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• pp.43-55
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• 2017

This study tries to examine papers on coastal terrace in the East Coast of South Korea and to summarize formative age and elevation of the terrace. Spatial and temporal variations of uplift rate in the Coast based on absolute age published are also reviewed. The terrace in the middle part in the Coast from Goseong to Samcheok distributes in an elevation of 10-20 m and its formative age is MIS 5a. The terraces during MIS 5e and 7 develop on an elevation of 20-35 m and 60-80 m, respectively. The mid-southern part in the Coast from Uljin to Yeongil Bay has the terraces with elevations of 10-25 m and 25-45 m and their ages are MIS 5a or 5c and 5e, respectively. The terraces with elevations of 10-25 m and 30-45 m correspond to MIS 5a and 5e, respectively, in the southern part in the Coast from Homigot to Busan. Assuming that elevation of sea level during the formation of each terrace is the same as in the present time, uplift rates in the Coast range from 0.05 to 1.36 m/ky with an average of approximately 0.33 m/ky. The highest and lowest rates since MIS 5 are found in the Gyeongju (approximately 0.39 m/ky) and Pohang (approximately 0.19 m/ky) areas. With a consideration of elevation of sea level at that time, however, the middle, midsouthern and southern parts in the Coast show uplift rates of 0.16-0.28 m/ky, 0.20-0.36 m/ky and 0.24- 0.36 m/ky since MIS 5, respectively, suggesting that the southern part in the Coast has experienced relatively higher uplift rate.

• Korean Journal of Soil Science and Fertilizer
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• v.18 no.2
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• pp.177-188
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• 1985

To clarify the characteristics and genesis of clayey terrace soils in Yeongnam area, macro-morphological features and soil profile development indexes were investigated with the sequential soils in Yeongcheon (inland region) and in Yeongil (coastal region). The results are summarized as follows; 1. According to the physiogaphy and landuse, the terrace soils were discernible to well drained yellowish red (5 YR) profile of higher terrace (Bancheon series), moderately well drained reddish yellow (7.5 YR) profile of middle terraces (Upyeong and Hwadong series), and lower terraces (Deogpyeong and Geugrag series) which were moderately well to imperfectly drained by paddy-fication. 2. The roundness and sphericity of the gravels contained in the terrace deposits were ranged around 0.543-0.546 and 0.723-0.722, respectively. The rounded to well rounded gravels were resemble to typical alluvial origins. 3. The amount of clay minerals formed in the soil horizons per 100g of parent materials were 50.8-30.7g while the rates of the clay leached were 30.1-7.4%, and the higher terrace had the more leaching rates. 4. The index of profile development of the terrace soils ranged from 37.95 to 22.01 and the index were positively correlated with relative elevations of the soils. The rates of clay leaching were positively correlated with the ratios of clay in the illuvial horizons to elluvial horizons. 5. A similarity was observed among cumulative grain size curves of the terrace soils, but the patterns of recalculated silt free cumulative grain size curve of terrace deposits in Upyeong soils in Yeongil area were abruptly different from down layer that suggest the soil to have bisequum profile.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.29 no.1
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• pp.157-165
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• 2011

This study is to be used as a fundamental material of rural amenity resources researches, such as excavating, establishing and modifying national agricultural landscape resources, so as to efficiently manage them. It is carried out with targeting traditional Darangyi-Rice terrace which has design factors of agricultural landscape resources. We have set up the standard range with practicable similar standard(Marginal Farmland and Less Favored Areas and etc), those of Japan, and the results of analyzing the characteristics of Darangyi-Rice terrace already known. As a result of the field investigation, it has been revealed that a great deal of Darangyi-Rice terrace are being used for not corresponding purposes, or damaged and disappeared. For preserving and well-managing Darangyi-Rice terrace as a rural landscape resource which has rural design factors, it should be advanced detailed and accurate studies on present conditions and changes of Darangyi-Rice terrace, with researches on significances, values, utilities and economical efficiency of Darangyi-Rice terrace by regions. In addition, we utilized various spatial imagery data in the researching process. Consequently, it is concluded that if high resolution imagery data is used, it can establish rather minute and accurate large-scale DB, and monitor elaborate changes as well. It is therefore thought that its application can be higher as actualizing DB hereafter.

• 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.