• Title/Summary/Keyword: 3단구

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A study on the change of chemical composition of sediment particles of terrace deposits - A case of fine sediments at Jeongdongjin area - (단구 퇴적층의 화학 조성 변화에 대한 연구 - 정동진 단구의 세립 물질을 사례로 -)

  • Kim, Jong Yeon
    • 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.

경주시 양남 제4기 역질 해안단구 퇴적층 풍화단면내 앨로패인(allophane) 교결층의 기원

  • 정기영;배진한;정창식
    • Proceedings of the Mineralogical Society of Korea Conference
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    • 2001.06a
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    • pp.115-115
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    • 2001
  • 경주시 양남면의 4기 단층으로 추정되는 수렴단층에 의해 절단되는 해안단구 퇴적층 풍화단면에서 저결정질 광물인 앨로패인 교결층을 기재하였다. 이들은 자갈퇴적층 내에 협재하는 수조의 모래층에 한정되어 형성되어 있으며, 3-17 cm 두께로 연장성이 매우 좋다. 편광현미경 관찰에 의하면 모래층에는 사장석편들이 다량 함유되어 있으며 앨로패인은 광학적 등방성의 치밀한 점토집합체들로서 사장석 입자를 선택적으로 교대하거나 자갈과 모래입자들을 피복하고 있다. 앨로패인은 광학적 이방성인 상하위층의 고령토질 점토피복물과 명확히 구분된다. 앨로패인의 전자현미분석에 의하면, Al/Si 원자비가 1.3-1.7 범위이고 평균값은 1.5이다. X선회절분석 결과 3.49$\AA$과 2.26$\AA$에서 두 개의 넓은 회절대가 관찰된다. 주사 및 투과전자현미경관찰에 의하면 앨로패인을 특정한 입자형태 없이 치밀한 겔상태를 이루고 있다. 열분석에 의하면 96$^{\circ}C$에서 큰 흡열피크와 992$^{\circ}C$에서 발열피크가 관찰되며, 총 45% 정도의 중량감소를 보인다. 사장석의 평균조성은 An$_{87}$이며, 사장석내 유리포유물의 전자현미분석결과는 화산암 화학분류도에서 현무암 영역에 도시된다. 이 지역의 기반암은 현무암질 라필리응회암이나 사장석편을 제외하고 벤토나이트화되어 있다. 따라서 해빈환경에서 사장석이 벤토나이트에서 분리되어 퇴적한 것으로 보인다. 앨로패인 교결층은 해수면 강하로 단구퇴적층이 지표로 노출된 후, Al의 함량이 높고 비교적 풍화에 약한 사장석이 선택적으로 풍화되어 생성되었다. 앨로패인으로 피복된 모래층 내의 자갈은 풍화반응이 지체되어 상하위층의 자갈과 비교하여 풍화도에 있어서 현저한 차이를 보인다.. 파이프 중심에서 외곽부로 갈수록 전기석의 함량은 줄어들고 있고 장석들이 알바이트ㆍ칼스베드 쌍정을 보이며, 흑운모가 각섬석보다는 우세하게 나타나고 있다. 전기석은 주상 결정, 자형 내지 반자형의 입자로 다색성을 보이며, 결정 중심에서 가장자리로 갈수록 파란색과 황갈색의 광학적 누대구조를 관찰할 수 있다. 일광광산에서 산출되는 전기석에 대한 현미경 관찰은 열수기원임을 지시하고 있다. 야외조사와 현미경 관찰의 예비조사에 의하면 일광광산의 전기석이 형성된 환경은 다른2가지 화학적인 저장소의 혼합 효과의 결과로 생성되어진 것으로 예상된다. 일광의 화강암류를 만든 마그마는 전기석을 형성할 만큼의 Fe-Mg성분이 충분하지 않았을 것이다. 화강암 내에 흑운모와 각섬석의 결정작용에 의해 마그마의 Fe-Mg성분이 고갈되어지고 이로 인해 그 함량이 감소하며 상대적으로 마그마 내에 남은 붕소(B$_2$O$_3$)는 열수로 용리되고 흑운모, 각섬석과 평형을 유지하며 열수에 남아있게 된다. 잔류용융체에 남은 붕소의 함량은 전기석을 만들기에 충분함에도 불구하고, Fe-Mg 함량이 부족하여 마그마 기원의 전기석 결정을 만들 수가 없다가 광맥이 형성된 시기에 또 다른 열수가 공급되면서 이전의 평형이 깨지고 기존의 흑운모와 같은 염기성 광물이 붕소(B)를 함유한 새로운 열수와 반응하여 전기석을 형성한 것으로 예상한다. 앞으로 전암과 광물에 대해 지화학적 연구를 통해 화강암류와 전기석과의 지화학적 연관성, 주성분 원소와 열수의 특성과의 상관관계, 전기석의 기원(마그마 기원인지 열수기원인지)이 보다 정확하게 파악될 것이다. 마그마 진화에 따른 전기석의 성분변화와 기원을 이용하여 일광광산의 동광화대를 형성한 마그마 계에서 열수계로 이어지는 지질학적 과정을 이해할 수 있을 것이며, 암석 성인론적 지시자로서

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Characteristics and Genesis of Terrace Soils in Yeongnam Area -III. Mineralogical Characteristics (영남지역(嶺南地域)에 분포(分布)된 단구지토양(段丘地土壤)의 특성(特性)과 생성(生成) 연구(硏究) -제(第)3보(報) : 광물학적(鑛物學的) 특성(特性))

  • Jung, Yeun-Tae;Um, Ki-Tae;Jung, Pil-Kyun;Ha, Ho-Sung
    • 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.

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Characteristics of Marine Terrace Sediments Formed during the Marine Isotope Stage 5e in the West South Coast of the Korean Peninsula (한반도 서남해안 MIS 5e 해안단구의 퇴적층 특성 연구)

  • Yang, Dong-Yoon;Han, Min;Kim, Jin Cheul;Lim, Jaesoo;Yi, Sangheon;Kim, Ju-Yong
    • Economic and Environmental Geology
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    • v.49 no.6
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    • pp.417-432
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    • 2016
  • It was firstly revealed in this research that the marine terrace of the Ijin-ri (Bukpyung-myeon, Haenam-gun) was formed during the last interglacial (Marine Isotope Stage 5e; MIS 5e). The marine terrace totally ranging from 4.8 m (asl) to 8.8 m (asl) is subdivided into 4 units; Unit I ranges 4.8-5.3 m, unit II ranges 5.3-6.9 m, unit III ranges 6.9-8.3 m, and unit IV ranges 8.3-8.8 m. Strong evidences that units II and III were formed during MIS5e were obtained based on OSL dating, the physical characterizations such as particle size distribution, magnetic susceptibility and water content, principal element and trace element analyses, and quantitative clay mineral analysis for samples at the 30 cm intervals. The rounded gravels on the marine terrace are regarded to be originated from the clastic materials transported directly from the surrounding mountains toward the marine and abraded in the coastal area, without any fluvial processes. During the warmest period (125k, unit II), the increase in rainfall, along with the rapid rise in sea level, was likely caused the high amount of clastic materials transported to the upper part of the beach. As a result of comparing clay mineral ratios of study site with those derived from sediments of either tidal flats, or the Yellow Sea, it is interpreted that the sediments of study site were influenced from the marine. The results will be used to investigate the hydrological activity and sedimentary environment during the high sea level in the past.

소양강 상류 하안단구의 지형면 특성과 퇴적물 분석

  • 이광률;윤순옥
    • Proceedings of the KGS Conference
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    • 2003.11a
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    • pp.3-7
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    • 2003
  • 북한강의 가장 큰 지류하천인 소양강은 발원지와 최상류부가 북한 지역이며, 상류부에서도 남한 지역은 휴전선에 접하여 군사지역이 많기 때문에 연구를 위한 접근과 활동이 쉽지 않다. 또한 하류부는 소양강댐으로 인해 하천 양안의 대부분이 소양호의 수면 아래에 수몰되어 있다. 이러한 이유로 인해 소양강을 대상으로 한 지리학 및 지형학적 연구 성과는 거의 없다. 소양강은 남한의 하천 유역분지 중 최북단에 위치하며 태백산맥에 바로 접하고 있어, 태백산맥 일대의 구조 운동으로 인해 활발한 하각(incision) 작용이 나타난다. (중략)

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Cosmogenic Nuclides Dating of the Earth Surface: Focusing on Korean Cases (우주선유발 동위원소를 이용한 지표면의 연대측정: 국내 사례를 중심으로)

  • Seong, Yeong Bae;Yu, Byung Yong
    • The Journal of the Petrological Society of Korea
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    • v.23 no.3
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    • pp.261-272
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    • 2014
  • Over the last three decades, advances in AMS (Accelerator Mass Spectrometry) and Noble Gas Mass Spectrometer make various application of terrestrial cosmogenic nuclides (CNs) to wide range of earth surface sciences possible. Dating techniques can be divided into three sub-approaches: simple surface exposure dating, depth-profile dating, and burial dating, depending on the condition of targeted surfaces. In terms of Korean landscape view, CNs dating can be applied to fluvial and marine terrace, alluvial fan, tectonic landform (fault scarp and faulted surfaces), debris landforms such as rock fall, talus, block field and stream, lacustrine and marine wave-cut platform, cave deposits, Pliocene basin fill and archaeological sites. In addition, in terms of lithology, the previous limit to quartz-rich rocks such as granite and gneiss can be expanded to volcanic and carbonate rocks with the help of recent advances in CNs analysis in those rocks.

The Coastal Geomorphic System of Sagye, Jeju (제주 사계해안의 지형시스템)

  • Seo, Jong-Cheol;Son, Myoung-Won
    • Journal of the Korean association of regional geographers
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    • v.13 no.1
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    • pp.32-42
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    • 2007
  • In Sagye coast of Andeok-myeon, southwestern Jeju, shore platform of noncohesive Hamori Formation, marine terrace deposit of round gravels, coastal dune composed of shell sand and volcanic sand, and back lake are linked closely with each other. In this paper, the formation process of Sagye coastal geomorphic system analysed by using OSL dating method is as follows: Firstly, Hamori Formation is a horizontal stratum filed up of tuff reworked by submarine volcanic eruption during 3$\sim$7.6 ka BP. Hollow at the boundary between Hamori Formation' flat and Kwangheak Basalt's gentle slope become a back lake when block is appeared over the sea level by uplift. Secondly, while Hamori Formation was laid below sea level, gravels which had been broken and abraded at southwestern rocky coast composed of Kwangheak basalt or been transported through the small stream from adjacent hillslope were deposited in rapid flow environment. Thirdly, deposition of round gravels was ceased by earth uplift, and shore platform was constructed by abrasion process of energy of swash moving forward. As altitude of shore platform is equal to high tidal level of spring tide, compared it with present high tidal level of study area, earth is uplifted about 105m since shore platform was formed. Fourthly, much sandy sediments transported from offshore bottom covered shore platforms and marine terrace deposits. Lighter sediments among sandy sediments was blown to back, formed secondary sand dune since about 500 year.

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Weathering Properties and Provenance of Loess-Paleosol Sequence Deposited on River Terrace in the Bongdong Area, Wanju-gun, Jeonbuk Province (전북 완주군 봉동 하안단구 상부 뢰스-고토양 연속충의 풍화특성과 기원지)

  • Hwang, Sang-Ill;Park, Chung-Sun;Yoon, Soon-Ock
    • Journal of the Korean Geographical Society
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    • v.44 no.4
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    • pp.463-480
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    • 2009
  • The weathering properties and provenance of loess-paleosol sequence deposited on gravel layer of river terrace in Bongdong-eup, Wangju-gun, Jeonbuk Province are examined using soil analysis, magnetic susceptibility measurement, grain size and element analysis. The Bongdong section consists of, from top to bottom, Layer 1(paleosol), Layer 2(loess), Layer 3(paleosol) and the gravel layer of river terrace. The magnetic susceptibility values show the systematic variations in the sequence and the results of grain size analysis reveal that the sequence was deposited by not fluvial or slope process, but eolian process, and that contains finer materials than the Daecheon loess and Chinese Loess Plateau. Among the results of soil analysis, organic contents indicate systematic variations similar to the magnetic susceptibility. The wet soil colors further reflect the characteristics of the sequence rather than the dry soil colors. Based on the analytical results of major and rare earth elements, the eolian materials contained in the sequence were deposited by the materials originated from the areas where the Chinese Loess Plateau has been originated or the reworked materials from the Chinese Loess Plateau, and after the depositions, the materials experienced the intensive chemical weathering under the humid-warm climatic conditions in the Korean Peninsula.

Studies on classification of Korean catfish (Silurus asotus) peripheral leucocytes (한국산 메기 (Silurus asotus)의 말초혈액 백혈구의 분류)

  • Park, Sung-Woo
    • Journal of fish pathology
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    • v.8 no.1
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    • pp.47-55
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    • 1995
  • Classification of peripheral leucocytes in Korean catfish (Silurus asotus) were performed. The leucocytes were classified on the basis of their morphological, cytochemieal and phagocytic characteristics. Four types of leucocytes were observed in the peripheral blood. Neutrophils were round and 12 - $15{\mu}m$ in diameter with round, oval or 2 - 3 segmented neuclei. Their cytoplam was stained whitish or grey. Lymphocytes were round and 5.5 - $8{\mu}m$ in diameter with large round neuclei which occupied most of the cells. Monocytes were round or irregular cells and 12 - $15{\mu}m$ in diameter with bean - shaped or irreular neuclei. Thrombocytes were oval or spindle - shaped cells with oval or spindle - neucle. The cells with greyish cytoplasm ranged 7.2 to $14.4{\mu}m$ in length and 5.8 to $7.2{\mu}m$ in width. Only neutrophils showed positive reaction in peroxidase and PAS. Neutrophils and monocytes showed active phagocytosis. As the results it is concluded that peripheral leucocytes of Koran catfish could be classified as lymphocytes, neutrophils, monocytes and thrombocytes.

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Instantaneous Frequency Estimation of Doppler Signal using Wavelet Transform (웨이브릿 변환을 이용한 도플러 신호의 순간 주파수 추정)

  • Son Joong-Tak;Lee Seung-Houn;Park Kil-Houm
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.42 no.3 s.303
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    • pp.99-106
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    • 2005
  • Instantaneous Frequency(IF) of Doppler signals is used to get the information of relative velocity and miss distance between a missile and the corresponding target. Though Short-Time Fourier Transform(STFT) is mainly used to estimate IF, it has many errors in wide band signals where frequency changes sharply. Because it has a fixed window in time and frequency axes. This paper deals with IF estimation of Doppler signal using a Continuous Wavelet Transform(CWT) which has adaptive window in time and frequency axes. The proposed method is able to estimate IF regardless of frequency changes because it has a narrow window in high frequency band and a wide window in low frequency band. The experimental results demonstrate that the proposed method outperforms STFT in estimating IF.