• Title/Summary/Keyword: 암석학

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Petrography and geochemistry of the Devonian ultramafic lamprophyre at Sokli in the northeastern Baltic Shield (Finland) (북동 Baltic Shield (핀란드) Sokli 지역의 데본기 초염기성 lamprophyre의 암석학 및 지구화학)

  • Lee, Mi-Jung;Lee, Jong-Ik;Jaques Moutte;Kim, Yeadong
    • The Journal of the Petrological Society of Korea
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    • v.12 no.4
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    • pp.170-183
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    • 2003
  • The Sokli complex in the northeastern Baltic Shield (Finland) forms a part of the extensive Devonian Kola Alkaline Province. The complex contains ultramafic lamprophyres occurring as dikes of millimetric to metric thickness. The Sokli ultramafic lamprophyres have petrographical and geochemical affinities with aillikite. High concentrations of Cr and Ni with low Al$_2$O$_3$ content of the Sokli aillikites indicate a strongly depleted harzburgitic source. However, compared to the kimberlites, the lower Cr and Ni contents and mg-number with weaker HREE depletion of the Sokli aillilkites imply a smaller proportion of garnet in the source and thus suggest a shallower melting depth of the source. In order to account for high concentrations of all incompatible elements and LREEs, with high volatile content (especially CO$_2$), an additional enriched material is thought to have been incorporated into the Sokli aillikite source. An anomalous enrichment of K in the Sokli aillikites, compared to nearby ultrapotassic rocks and world-wide ultramafic lamprophyres, indicate a presence of K-rich phase (probably phlogopite) in the source mantle.

Variation of Rare Earth Element Patterns during Rock Weathering and Ceramic Processes: A Preliminary Study for Application in Soil Chemistry and Archaeology (암석의 풍화과정 및 도자기 제조과정에 따른 희토류원소 분포도의 변화: 토양화학 및 고고학적 응용을 위한 기초연구)

  • Lee, Seung-Gu;Kim, Kun-Han;Kim, Jin-Kwan
    • The Journal of the Petrological Society of Korea
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    • v.17 no.3
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    • pp.133-143
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    • 2008
  • On the basis of chemical composition of granite, gneiss and their weathering products, in this paper, rare earth elements (REEs) was estimated as tracer for clarifying a geochemical variance of earth surface material during weathering process. The chemical composition of clay, clay ware and pottery also were measured for testifying usefulness of REE geochemistry in clarifying the source material of pottery. It was observed that there was no systematic variation of chemical composition among source rock, weathered rock and soil during weathering process. The chemical composition of clay, clay ware and pottery also did not show systematic variation by baking pottery. However, PAAS (Post Archean Australian Shale)-normalized REE patterns of rock-weathered rock-soil and clay-clay ware-pottery are similar regardless of weathering process or ceramic art. Our results confirm that REE geochemistry is powerful tool for clarifying the source materials of surface sediment or archaeological ceramic products.

Distribution of Some Environmental Radionuclides in Rocks and Soils of Guemjeong-Gu Area in Busan, Korea (부산시 금정구 일대 암석 및 토양에서 일부 환경방사성 핵종들의 분포 특성)

  • Lee, Hyo-Min;Moon, Ki-Hoon;Kim, Jin-Seop;Ahn, Jung-Keun;Kim, Hyun-Chul
    • The Journal of the Petrological Society of Korea
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    • v.17 no.3
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    • pp.179-190
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    • 2008
  • The distribution characteristics of some major environmental radionuclides ($^{40}K$, $^{228}Ac$, $^{226}Ra$, $^{222}Rn$) and U in rocks, soils and soil gas were studied at Geumjeong-Gu, Busan, Korea. The activities of radionuclides in granitic rocks are decreased in the odor of $^{40}K$>thorium decay series>uranium decay series. This reveals that Th was relatively more enriched in granitic rocks than U. The U content and activity of $^{226}Ra$ and $^{228}Ac$, however, don't reflect the fractionation sequence of granitic rocks in the study area. The activities of all these radionuclides and U content in soils are generally higher than in rocks, and their distribution in rocks, soils and soil gas show very low co-relationship. These facts indicate that the activities of radionuclides in soil and soil gas were greatly affected by leaching and adsorption properties of the radionuclides and their parents during weathering and pedogenetic process rather than their concentrations in parent rocks.

Study for Selection of Replica Stone of the Stele for Buddhist Monk Wonjong at Yeoju Godalsa Temple Site using Magnetic Susceptibility (전암대자율을 이용한 여주 고달사지 원종대사탑비 비신의 복제용 석재 선정 연구)

  • Lee, Myeong Seong;Chun, Yu Gun;Kim, Jiyoung
    • The Journal of the Petrological Society of Korea
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    • v.25 no.3
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    • pp.299-310
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    • 2016
  • The Stele for Buddhist Monk Wonjong at Godalsa Temple Site was destroyed a long time ago. Only the tortoise-shaped pedestal and the ornamental capstone in the form of a hornless dragon remain at the site and the broken stele body is stored at the National Museum of Korea today. The stele is made of two kinds of rocks that are coarse-grained biotite granite for the pedestal and the capstone, and fine-grained biotite granite including hornblende assemblages and feldspar phenocrysts for the stele body. The coarse-grained biotite granite of the pedestal and capstone showed same magnetic susceptibility and lithological characteristics with biotite granite outcrops in Yeoju area, whereas the fine-grained granite of the stele body did not. To find a provenance of the stele body stone, we investigated Korean granites in terms of magnetic susceptibility, lithology and old recordings about construction process of the stele. As a result, Haeju granite is the most likely to be a cognate rock of the stele body stone as it has same texture and lithological characteristics like color, hornblende assemblages, mineral composition and magnetic susceptibility. It is imported from Haeju (North Korea) to South Korea via China commercially, and the most suitable for a replica stone of the stele body.

Earth and Environmental Sciences with Synchrotron Radiation (방사광의 원리와 지구환경과학에의 응용)

  • 김영호
    • The Journal of the Petrological Society of Korea
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    • v.10 no.3
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    • pp.212-221
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    • 2001
  • This paper introduces the characteristics and generation of the synchrotron radiation (SR). SR has the very high spectral brilliance, broad spectral range, X-ray wavelength tunability, high degree of polarization and collimation, and pulsed time structure. Also describes the technologies to apply in the fields of geology and environmental sciences. These include X-ray tomography, XRF, EXAFS, XANES, DAC, IVP experiments. Further, nuclear power generation and nuclear waste disposal methods are mentioned relating to energy. Using these, analyses of the chemistry, crystal structure and chemical combining states of minerals and rocks can be carried out. Applications in the fields of the economic geology, paleontology and environmental sciences are open too. Informations of the Earth interior materials' behavior under high pressure-temperature can be acquired.

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The Statistical on Numerical Analysis for The Petrology and Bulk Chemical Composition. In Cheju Volcanic Island (제주화산도의 암석성분에 관한 통계학적인 수치해석)

  • 택훈
    • Journal of the Speleological Society of Korea
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    • v.14 no.15
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    • pp.42-90
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    • 1987
  • Lee, Moon Won reported by 63 kinds lescribing the petrography and bulk chemical Composition in Petrology of Cheju volcanic island. The total Chemical Composition data was analyzed by the program of FORTRAN77. First, the Conversition equations and the scatter diagram were examined to the analysis, by the least square method. Next, a statistical data requested a mean Value, maximum value, minimum value, the range, the standard deviation, the variance, the Standord Error and the Coefficient of variation. In the standard deviation, a small Composition is MnO and P$_2$O$\sub$5/, a large Composition is SiO$_2$, Mgo and FeO. The Standard error and the variance were the tandency looked like the Standard deviation well. However, the Coefficient Variation differs from the Standard deviation. Where, a large Coefficient of variation are H$_2$O$\^$-/ and H$_2$O$\^$+/, a small Coefficient of variation are Al$_2$O$_3$ and SiO$_2$. The Correlation of Coefficient Can be Calculated numerically from the relation between SiO$_2$, Al$_2$O$_3$ and TiO$_2$ to other Compositions.

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Weathering Characteristics of Sedimentary Rocks Affected by Periodical Submerging (주기적으로 침수되는 퇴적암의 풍화특성)

  • 이석훈;김수진
    • Journal of the Mineralogical Society of Korea
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    • v.17 no.1
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    • pp.23-35
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    • 2004
  • The weathering characteristics of periodically submerged sedimentary rocks in the Sayeon dam, Ulsan was examined by field work, electron probe micro-analysis, X-ray diffraction, and X-ray fluorescence spectrometry. Analysis of fracture zone and exfoliation showed the submerged sedimentary rocks have undergone severe mechanical weathering. Mechanical weathering in the water-rock interface accelerated chemical weathering, such as dissolution and alteration of the most of minerals except for quartz in the weathering zone. The dissolution of carbonates specially calcite, is remarkable creating the cavities, whereas formation of minerals including clay minerals is not active. The sedimentary rocks have been periodically submerged for a certain period of time, and have repeated freezing and thawing. This mechanical weathering favored infiltration, which accelerated mineral dissolution. The high content of easily soluble carbonate of the sedimentary rocks is likely the major cause of intense chemical weathering. The dissolved elements within the infiltrated water interrupted the occurrence of clay and weathering minerals, and expend fractures by infiltrated water accelerated weathering process.

Petrographic and Geochemical Characteristics of the Komatiite from the Gorgona Islands in the Pacific Ocean of the Colombia, South America (남미 콜롬비아의 태평양 연안 골고나 섬산 코마티아이트의 암석학적 및 지화학적 특징)

  • 진명식;신홍자
    • The Journal of the Petrological Society of Korea
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    • v.12 no.2
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    • pp.55-69
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    • 2003
  • A spinifex textured komatiite sample of Early Tertiary age, from the Gorgona Islands of Colombia in South America, was petrographically and geochemically studied, and compared with the previous researches of the komatiites including other Precambrian komatiites in South Africa, Western Australia and Canada. The sample shows the komatiitic characteristics in its petrography and geochemistry very well, i.e. in high specific gravity (2.98) and density (3.2), rock forming minerals, spinifex texture, major and race element abundances and REE pattern. In particular the REE pattern for it strongly suggests that the Gorgona komatiite must have been crystallized from a magma generated from a depleted mantle as that of Munro Township area in Ontario, Canada which is pyroxenite komatiite or basaltic komatiite of Group I of the Archean.

Petrologic Evolution of the Songaksan Monogenetic Volcano, Jeju Island, Korea (제주도 송악산 단성화산의 암석학적 진화)

  • 황상구;원종관;이문원;윤성효;이인우;김성규
    • The Journal of the Petrological Society of Korea
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    • v.10 no.1
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    • pp.13-26
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    • 2001
  • Songaksan volcano, which occurs as a monogenetic volcano on the southwestern promontory of Hallasan shield volcano, is composed of tuff ring, cinder cone, lava pond and cinder conelet complex on wide basalt plateau. Except for an influx of external quartz xenocrysts in the tuff ring. Totally the volcano ranges from trachyandesite to trachybasalt in petrography and chemical compositions, which confirm the continuum between the evolved and primitive compositions widely occurring in the Jeju volcanic system. Chemical data for the volcano show quantitative compositional variation from the lower to the upper part of the volcanic sequences. The continuous compositional variations generally define a compositionally zoned magma storage. The chemical data suggest that the compositiona1 donations might have resulted from the fractional crystallization of a parental alkali magma. As result, the Songaksan volcano initially tapped the lop of the zoned magma storage and subsequently erupted successively more primitive magma.

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Petrological Study and Provenance Estimation on the Stone Materials from Outer Rampart of the Namhansanseong Fortress, Korea (남한산성 외성 성벽부재에 대한 암석학적 연구 및 산지추정)

  • Park, Sang Gu;Park, Sung Chul;Kim, Jae Hwan;Jwa, Young-Joo
    • The Journal of the Petrological Society of Korea
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    • v.26 no.4
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    • pp.353-360
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    • 2017
  • The preservation treatment for the outer rampart of Namhansanseong fortress is needed due to partial collapse and separation of stone materials. In this study, we investigated the petrological features of the stone materials used for the outer rampart and estimated their provenances through the geologic survey. Through the above study, the suitable replacement stone in the maintenance of outer rampart were suggested. The stone materials of the above outer rampart consist of the banded gneiss, augen gneiss, granitic gneiss and porphyroblastic gneiss. Among these four kinds of rocks, granitic gneiss is quantitatively the most abundant. Petrological comparisons between stone materials and rocks distributed around the fortress, lead to the conclusion that the above materials are likely to have been delivered from around the fortress. Judging from the results of the comparison on frequency of use and strength characteristics among the above rocks, the granitic gneiss is considered to be suitable for restoration of the outer rampart of the fortress.