• Title/Summary/Keyword: 화학연대

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Petrology of the Igneous Rocks in the Goseong area, Gyeongsang Basin II. Trace Element Geochemistry and Rb-Sr Radiometric Age (경상분지 고성지역의 화성암류에 대한 암석학적 연구 II. 미량원소 지구화학과 Rb-Sr 방사성 연대)

  • Jwa, Yong-Joo
    • Economic and Environmental Geology
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    • v.31 no.6
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    • pp.473-483
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    • 1998
  • The igneous rocks in the Goseong area are composed of the volcanic rocks (andesitic lapilli tuff and rhyodacite), Bulgugsa granites (Hornblende-biotite granite and two pyroxene granite) and intrusive andesites. In the variation diagrams of the trace and rare earth element contents and elemental ratios as well as the REE patterns, the three igneous rock types show different variational trends and patterns. The geochemical features represent that the igneous rocks in the area were formed from three different magmatic pulses. Two independently carried out Rb-Sr isotope experiments for the Goseong granites show that the whole rock ages and Sr initial ratios of the granites are $66.4{\pm}6.2Ma$, $0.70517{\pm}22(2{\sigma})$ and $71.3{\pm}6.8Ma$, $0.70506{\pm}18(2{\sigma})$, respectively. These results suggest that the granites magma originated from the lower crustal materials of igneous origin intruded into the area during the late Cretaceous period. Masan hornblende-biotite granite emplaced at the vicinity of the Goseong area is very similar to the Goseong granite in its mineral compositions, major, trace and rare earth element contents and patterns. The intruding age (100 Ma) of the Masan granite is order than that of the Geseong granite, however. The similarity of the geochemical natures but the contrast of the intruding ages between the Masan and Goseong granites possibly indicate that the magma generation from the same source materials occurred at a temporal interval of ca. 30 Ma.

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Sedimentary Characteristics and Chronology of Loess-paleosol Sequence in Jeongjang-ri, Geochang basin, Gyeongnam Province (경남 거창분지 정창리 뢰스-고토양 연속층의 퇴적물 특성과 편년)

  • Hwang, Sang-Ill;Kang, Chang-Hyeok;Yoon, Soon-Ock
    • Journal of the Korean Geographical Society
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    • v.46 no.1
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    • pp.1-19
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    • 2011
  • The physical and chemical characteristics of loess-paleosol sequence in Jeongjang-ri, Geochang basin are examined using the magnetic susceptibility measurement, grain size analysis, OSL age dating, major, rare earth and trace elements analysis. The grain size characteristics of the loess-palesol sequence are obviously different from those of river sediment forming river terrace deposits and the Chinese Loess Plateau. The loess-paleosol sequence consisting of L1, L1LL1, L1S1, L1L2, S1 and L2 from top to bottom is estimated to MIS 2~MIS 6 and the river terrace to MIS 7. The compositions of major, rare earth and trace elements indicate that the sequence show more weathered characteristics than the Chinese Loess Plateau and originated from the Chinese Loess Plateau. These features are in harmony with the previous studies in Korea.

Petrology of the Igneous Rocks in the Goseong Area, Gyeongsang Basin I. Major Element Geochemistry and K-Ar Radiometric Age (경상분지 고성지역의 화성암류에 대한 암석학적 연구 I. 주성분원소 지구화학과 K-Ar 방사성 연대)

  • Jwa, Yong-Joo;Park, Jeong-mi
    • Economic and Environmental Geology
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    • v.29 no.5
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    • pp.561-573
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    • 1996
  • The igneous rocks in the Goseong area, the southwestern part of the Gyeongsang basin, are composed of the volcanic rocks, Bulgugsa granites and intrusive andesites. The volcanic rocks are andesitic lapilli tuff, dacite and rhyolite. The granites are mainly of hornblende-biotite granite and intruded into the sedimentary basement and the volcanic rocks. The intrusion of andesitic dyke is thought to be the latest igneous activity in the area. In the variation diagrams of the major oxides, the three igneous rock types show different variational trends, indicating that they were from the different magmatic pulses. K-Ar radiometric ages suggest that the igneous activity in the Goseong area had occurred during late Cretaceous period. The ages of the volcanic rocks seem likely to have become younger due to the thermal effect by the granitic intrusion. The major element compositoinal variation of the granites from the Goseong area are compared with those from the Jindong, Geoje and Masan areas. By the comparison, it is easily understood that the Jindong granites are fairly different from the other three granites. On the other hand, the Goseong, Geoje and Masan granites generally show similar variational trends with each other, suggesting that they are of similar genetic origin. Combining the similarity of the geochemical features and the difference of the intruding ages between the Goseong and Masan granites, it seems like that the magma generation from the same source materials had occurred at a temporal interval.

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Anatomical Characteristics and Trace Elements of Historical Papers and Cloths from Neunggasa Temple in Korea (능가사 출토 종이와 섬유의 해부학적 성질 및 미량원소 분석)

  • Wazny, Agnieszka Helman;Park, Won-kyu
    • Journal of Conservation Science
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    • v.10 no.1 s.13
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    • pp.1-9
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    • 2001
  • The objective of this study is to examine the characteristics of historical papers and cloths found at Neunggasa temple, Goheunggun, Chonnam Province, Korea, using light microscopy, image analysis and SEM-EDS for fiber morphology and trace metal composition. All papers were made from paper mulberry. Transparent membrane, which was separated from bast fiber, was unique in these fibers. The papers found on the wall of Daewungjun were most highly degraded and those of the books, which were excavated under Cheungwangmun, were relatively well preserved. The cloths found under the statue 'Dong-bangjiguk' were silk, very narrow fiber without any marks. In the analysis of SEM-EDS, high content of silica was detected. Also small content of calcium was taken into consideration. Content of iron and chlorine were discussed from the viewpoint of potentially harmful elements for the conservation of paper. The composition of trace elements could not be used to determine the origins of papers.

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제조물책임법(製造物責任法) 도입(導入)의 경제적(經濟的) 효과(效果)와 입법방향(立法方向)

  • Sin, Gwang-Sik;Gu, Bon-Cheon
    • KDI Journal of Economic Policy
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    • v.18 no.3_4
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    • pp.3-61
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    • 1996
  • 소비자 보호 및 효율적 자원배분, 기업의 안전증진 유인제공, 제도의 국제적 조화를 위하여 제조물책임법(製造物責任法) 제정의 필요성이 제기되고 있다. 현재 제조물로 인한 사고는 민법(民法)에 의하여 보상받고 있으나 그 입증책임이 과중하고, 현재 우리나라 생산물배상책임보험(生産物賠償責任保險)이 전체 손해보험에서 차지하는 비중은 0.1%에 불과(미국 10%)하여 그 비용이 아직 미미하므로 제조물책임법제(製造物責任法制) 도입의 안전증진효과가 경제적 손실보다 클 것으로 예상된다. 법제정시의 기본방향은 소비자에게 단순히 보상을 제공하는 법제가 아닌, 기업의 책임과 제품결함이 밀접히 연관되어 배상(賠償) 및 사고억제(事故抑制)의 유인과 효과를 극대화하는 것이어야 한다. 추정규정의 도입은 소비자(消費者) 피해구제(被害救濟)를 용이하게 하지만, 디자인 및 경고결함(警告缺陷)과 결합되면 제조자가 제품사고의 모든 가능성에 대해 완벽한 정보를 가지지 않는 한 제조자의 책임이 되어 제조물책임(製造物責任)의 불확실성(不確實性)을 높이고, 결과적으로 기업에게 절대책임(絶對責任)을 부과하게 되어 제품개발과 혁신을 위축시키는 등의 부정적(否定的) 영향을 초래할 위험이 크다. 따라서 결함의 추정은 인정하지 않아야 하며, 제품개발 및 혁신을 도모하기 위해 개발위험항변(開發危險抗辯)은 인정되어야 한다. 손해배상액(損害賠償額) 상한(上限)을 두지 않는 것이 경제적으로 효율적이고 연대책임을 인정하여 유통업자의 안전제고유인(安全提高誘因)도 강화하는 것이 효과적이다. 중소기업을 포함한 모든 기업에게 입법후 1년 정도의 준비기간(準備期間)을 주는 것이 바람직할 듯하며, 배상책임보험(賠償責任保險)은 의무화하지 않는 것이 경제적으로 효율적이다. 기계, 전자, 운송용기기, 건설, 화학, 식 의약품, 가스제품, 완구, 운동용구 등이 영향을 크게 받을 것으로 예상되지만 법제이용(法制利用)의 편의가 개선되기 전에는 소송의 증가는 미미하리라 예상된다.

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Characteristics and depositional environment of paleosol layers developed on top of the terrace in the Jeongdongjin area, East Coast, Korea (강릉 정동진 지역 단구 고토양층의 특징과 퇴적 환경)

  • Yi, Seon-Bok;Lee, Yong-Il;Lim, Hyun-Soo
    • The Korean Journal of Quaternary Research
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    • v.23 no.1
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    • pp.1-24
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    • 2009
  • Paleosol layers lying on top of the terrace in Jeongdongjin area appear to have been deposited under generally well-drained condition with periodic waterlogging. From a 4.5m-long profile observed, a total of 6 stratigraphic units were identified. Grain-size analysis indicates the dominance of silty and clay materials with some portions with high sand content. Major mineralogical elements are quartz, feldspar, mica and chlorite. Geo-chemical composition shows little change throughout the stratigraphy with some fluctuation in chemical weathering index. Marked increase in magnetic susceptibility is recognizable where stratigraphic unit changes. Soil- wedge layer is developed around 50cm below the surface with concentration of grains of AT tephra (c. 25,000 BP). An OSL date of c. 110,000 BP was obtained from a sand layer lying below the paleosol.

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Characteristics of a Turbidite Sediment from the Southern Margin of the Okinawa Trough, Japan (오끼나와해곡 남쪽해역의 저탁류 퇴적물의 특성)

  • 현상민
    • 한국해양학회지
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    • v.30 no.2
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    • pp.69-76
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    • 1995
  • A turbidite core sediment (RN88-PC5) from 2051 m on the deep-sea floor at the southern margin of Okinawa Trough was examined. Sedimentological characteristics were quite different between sandy sediments and hemipelagic sediments and hemipelagic sediments in terms of benthic foraminiferal assemblage, grain-size and chemical composition. All turbidite sandy sediments were clearly transported from shallow area as they include typical coral reef dwelling benthic foraminifera which were not found in the background hemipelagic sediments. These layers also suggest that the sediments were transported by turbidity-related currents and implies that sedimentological mechanisms were different between sandy sediments and hemipelagic sediments. The result of the /SUP 14/ C age dating and the stable oxygen isotopic fluctuation of planktonic foraminifera show a gradual warming trend of the surface water from about 10 Ka to present. Also Termination lb as well as two fresh water input events were recognized at ca2 and 7 ka.

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A Study on the Physicochemical Characteristics and Formation Age of Coastal Sand Dunes in the Okjukdong and Dajindong, Daecheong Island (대청도 옥죽동·대진동 사구의 물리·화학적 특성 및 퇴적시기 고찰)

  • Shin, Won Jeong;Kim, Jong Wook;Kim, Jong Yeon
    • Journal of The Geomorphological Association of Korea
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    • v.25 no.2
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    • pp.63-80
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    • 2018
  • The purpose of this study was to investigate the physicochemical characteristics and formation age of sand dunes in the Okjukdong and Dajindong, Daecheong Island. As a result, most of the sand deposited in Okjukdong were composed of medium sized sand with moderately well sorted. The $SiO_2$ and $Al_2O_3$ accounted for a very high proportion of these deposits. There were some differences in characteristics between the sands in the dune and beach, whereas similar characteristics were observed among the materials (OJ-B, OJ-C and OJ-D) in the dune. In case of Dajindong, heterogeneous geochemical characteristics were found in the lower point. It was estimated that this was due to the influence of Daejin-dong black beach. Age dating results showed that uncovered dunes in Okjukdong were deposited $0.44{\pm}0.02$ ~ $0.50{\pm}0.02ka$, and sand depositsin Dajindong were formed $0.16{\pm}0.01$ ~ $0.18{\pm}0.01ka$. In both Okjukdong and Dajindong, sand deposits estimated to be formed 70 years ago, therefore it can be estimated that sand movement was active throughout the area from about hundred years ago. In this study area, the growth of sand dunes has been active in recent several decades or hundred years. It seems that there were different regions where deposits predominated over time. The source of dune sand was also different from time to time. Since the windbreak forest was established, the natural growth of sand dunes was limited, and sand nourishment was carried out by period. Therefore, in order to protect and continuously utilize coastalsand dunesin Daecheong Island, it is necessary to prepare conservation plan.

Lead isotope measurement of geological reference materials using thermal ionization mass spectrometry (열이온화질량분석기를 이용한 암석표준시료에 대한 납 동위원소 분석)

  • Lee, Hyo Min;Jo, Hui Je;Kim, Taehoon
    • Analytical Science and Technology
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    • v.33 no.6
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    • pp.245-251
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    • 2020
  • Lead (Pb) has been shown to be a useful tracer of contamination sources and geochemical processes such as age dating and crustal evolution. These studies require a chromatographic technique for Pb separation from geological samples. This paper presents a comparison study on the effect of eluent concentration between 6M HCl and 8M HCl on the separation of Pb from Pb resin. The results showed that the separation of Pb using 6M HCl as the eluent was not effective compared to the separation using 8M HCl. To verify this method, we measured the Pb isotopic compositions of the Pb isotopic standard (NIST NBS981) and geological reference materials (BCR-2, GSP-2, and JG-1a) using a thermal ionization mass spectrometer (TIMS). The results correspond well with the reported values within the error range, implying that this method can be useful.

Division of Soil Properties in Reclaimed Land of the Mangyeong and Dongjin River Basin and Their Agricultural Engineering Management (만경강과 동진강 유역 간척농경지 토양특성 구분과 농공학적 관리 대책)

  • Hwang, Seon-Woong;Kang, Jong-Gook;Lee, Kyung-Do;Lee, Kyung-Bo;Park, Ki-Hun;Chung, Doug-Young
    • Korean Journal of Soil Science and Fertilizer
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    • v.45 no.3
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    • pp.444-450
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    • 2012
  • The physical and chemical properties of soil in the Mangyeong and Dongjin river basin had been investigated in order to establish the most optimum soil improvement plan on the reclaimed land. The total soil area by reclamation in Saemangeum basin is 113,971 ha. The classification by the distribution of soil series and soil texture is as following. 13 soil series including Chonnam, Buyong and Chonbuk series are period-unknown areas. Regarding the soil texture, they are fine silty ~ clayey very fine. From 1920s to 1960s, Mangyeong, Gwanghwal and Chonbuk series had coarse silty textured soil. After the 1970s, Mangyeong, Gwanghwal, Munpo, Yeompo, Poseung, Gapo and Hasa series have more sandy soil ~ moderately coarse loamy textured soil. Regarding the chemical properties, the concentrations of EC, Exch. $K^+$, $Mg^{2+}$, $Na^+$ and pH are high regardless of the time of reclamation. On the other hand, organic matter (OM) of top soil were 3.3~16.1 g $kg^{-1}$. The organic matter contents were very low though the soil had been farmed for a long time. Furthermore, the deep soil had almost no organic matter with 5.6~1.1 g $kg^{-1}$. The reason is believed that there had not been any movement of OM and clay because pressure or induced pans had been formed by large agricultural machineries and poor vertical drain. Regarding the forming of illuvial horizon (B layer) which tells the development extent of soil, only in the Hwapo reclaimed area where rice had been cultivated for past 90 years, Fe and Mn from top soil are deposited at underground 20~30 cm with 7~8 cm thickness by the movement of clay. It is believed that it had been possible because the earthiness is silty clay loam soil with relatively high content of clay. The soils are soil with concern of damage from sea water, soil on flimsy ground and sandy soil. Therefore, soil improvement for stable crop production can be expected; if the water table would be lowered by subsurface drainage, the water permeability would be enhanced by gypsum and organic matter, and the sandy soil would be replaced by red soil with high content of clay.