• Title/Summary/Keyword: geochemical distribution

Search Result 164, Processing Time 0.026 seconds

Study on the Metal Ore Deposits of Gyeongsang buk-do Area (경상북도(慶尙北道) 일원(一圓)에 부존(賦存)하고 있는 금속지하자원(金屬地下資源)의 지질광상학적(地質鑛床學的) 연구(硏究))

  • Kim, Y.K.;Lee, J.Y.;Kim, S.W.;Koh, I.S.
    • Economic and Environmental Geology
    • /
    • v.9 no.3
    • /
    • pp.143-156
    • /
    • 1976
  • The Cretaceous metal ore deposits in the Gyeongsang basin of Gyeongsangbuk-do are characterized by the formation of metallogenic provinces which show zonal distribution pattern around Yeonil province where pneumatolytic type is dominated and hydrothermal type are distributed in the order of decreasing temperature type outward. Some Cretaceous granitic rocks include zoned alkali feldspars which reflect rapid variation of $H_2O$ during emplacement and crystallization of the water-saturated granitic magma. The ore deposits are considered to be originated from upward transportation of ore solution from the excess of water exhausted from uprising magma, which seems to be intimately related to the fact that the majority of the ore deposits in Daegu area are cummulated around the granites including zoned alkali feldspars. In order to collect geochemical data necessary for geochemical exploration in the study area, certain trace elements were chosen as pathfinders from monzonite and soil in the vicinity of Dalsung Tungsten Mine by studying the dispersion patterns of trace elements: Ba and Sr show trends to decrease toward ore deposit while Cu, Pb, and Mo increase. Around mining area there are distributed apparently Equisetum arvense Linne and Mentha sachinensis Kudo which may be used as index plants. In the viewpoint of geologic structure, the trends of the ore veins in contact aureole around the Palgongsan granite body correspond with the pre- and syn- plutonism joint pattern in hornfels in the area.

  • PDF

Assessment of Natural Attenuation Processes in the Groundwater Contaminated with Trichloroethylene (TCE) Using Multi-Species Reactive Transport Modeling (다성분 반응 이동 모델링을 이용한 트리클로로에틸렌(TCE)으로 오염된 지하수에서의 자연저감 평가)

  • Jeen, Sung-Wook;Jun, Seong-Chun;Kim, Rak-Hyeon;Hwang, Hyoun-Tae
    • Journal of Soil and Groundwater Environment
    • /
    • v.21 no.6
    • /
    • pp.101-113
    • /
    • 2016
  • To properly manage and remediate groundwater contaminated with chlorinated hydrocarbons such as trichloroethylene (TCE), it is necessary to assess natural attenuation processes of contaminants in the aquifer along with investigation of contamination history and aquifer characterization. This study evaluated natural attenuation processes of TCE at an industrial site in Korea by delineating hydrogeochemical characteristics along the flow path of contaminated groundwater, by calculating reaction rate constants for TCE and its degradation products, and by using geochemical and reactive transport modeling. The monitoring data showed that TCE tended to be transformed to cis-1,2-dichloroethene (cis-1,2-DCE) and further to vinyl chloride (VC) via microbial reductive dechlorination, although the degree was not too significant. According to our modeling results, the temporal and spatial distribution of the TCE plume suggested the dominant role of biodegradation in attenuation processes. This study can provide a useful method for assessing natural attenuation processes in the aquifer contaminated with chlorinated hydrocarbons and can be applied to other sites with similar hydrological, microbiological, and geochemical settings.

Geochemical Study of Coastal Sediments around the Samcheonpo Coal-fired Power Plant (삼천포화력발전소 주변해역 퇴적물의 지구화학적 연구)

  • Lee, Doo-Ho;Lim, Ju-Hwan;Jeong, Yeon-Tae;Jeong, Nyeon-Ho;Kang, Jeong-Won
    • Journal of Environmental Impact Assessment
    • /
    • v.10 no.2
    • /
    • pp.85-98
    • /
    • 2001
  • This study was conducted to investigate the geochemical factors governing the distribution of heavy metals(Co, Cr, Cu, Fe, Mn, Ni, Pb, and Zn) in the marine surface sediment samples collected from the Samcheonpo coal-fired power plant. Variations of absolute metal concentrations were related to those in textural and/or carbonate and organic matter content. Most elements, except for Pb, showed generally lower contents compared with the average shale concentration, and the effect of anthropogenic input appeared to be minimal in the sediments. Computations of LF%(labile fraction) and EF(enrichment factor) based on all trace metal data indicated the presence of mineralogical control for Co, Cr, Cu, Ni, and Zn, and anthropogenic contamination for Pb, which needs to be considered in the design of long term monitoring programmes.

  • PDF

Atmospheric Chemistry of Mercury in the Polar Regions and its Environmental Implications (극지환경 수은의 대기화학과 환경학적 의미)

  • Schroeder, WH;Kim, Min-Young;Hong, Sung-Min;Shon, Zang-Ho;Kim, Ki-Hyun
    • Journal of the Korean earth science society
    • /
    • v.24 no.5
    • /
    • pp.420-427
    • /
    • 2003
  • The results of recent studies indicate that atmospheric distribution of Hg in the arctic environment is unique enough to show strong depletion during spring followed by notable increases during summer. The observations of this abnormal trend contrast quite sharply with what had been recognized as Hg geochemical behavior in air over the past decades. Using the long-term measurement data of Hg obtained from both the Arctic and Korea, we attempted to provide valuable insights into the unique mercury depletion phenomenon (MDP) in the polar regions of the globe.

Mineralogical-geochemical Characteristics of Manganese Nodules in the Deep Subseafloor Sediments at Site U1371 in the Western South Pacific Gyre Area (남서태평양 환류지역 U1371 심부퇴적층에서 발견된 망가니즈단괴의 광물학적-지화학적 특성 연구)

  • Yang, Kiho;Jung, Jaewoo
    • Ocean and Polar Research
    • /
    • v.44 no.2
    • /
    • pp.139-145
    • /
    • 2022
  • Manganese nodules were recovered within the deep subseafloor sediments (118.22 mbsf) at Site U1371 during International Ocean Discovery Program (IODP) expedition 329 from the South Pacific Gyre (SPG). Because most manganese nodules exist on the seabed surface, nodules present in deep sediments are uncommon. Therefore, the growth origin of manganese nodules was identified through mineralogical and geochemical analyses. The manganese nodule was divided into the concentric layer outside the manganese region and the inner part of the phosphatized region consisting of manganese oxide minerals and carbonate fluorapatite (CFA) minerals, respectively. The two-dimensional element distribution analysis of Mn, Co, Ni, Sr and Cu, Zn with low Mn/Fe ratio confirmed that manganese nodules were formed predominantly by a hydrogenetic process and a biogenic process in certain manganese layers. As a result, the manganese nodule was continuously precipitated in SPG environments of oligotrophic open paleoocean conditions and rapidly buried with siliceous ooze sediments when the SPG changed to a eutrophic environment. It has been confirmed that manganese nodules found within deep subseafloor sediments could be used as a new proxy for the reconstruction of paleooceanographic conditions.

Evaluation of Americium Solubility in Synthesized Groundwater: Geochemical Modeling and Experimental Study at Over-Saturation Conditions

  • Hee-Kyung Kim;Hye-Ryun Cho
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
    • /
    • v.20 no.4
    • /
    • pp.399-410
    • /
    • 2022
  • The solubility and species distribution of radionuclides in groundwater are essential data for the safety assessment of deep underground spent nuclear fuel (SNF) disposal systems. Americium is a major radionuclide responsible for the long-term radiotoxicity of SNF. In this study, the solubility of americium compounds was evaluated in synthetic groundwater (SynDB3), simulating groundwater from the DB3 site of the KAERI Underground Research Tunnel. Geochemical modeling was performed using the ThermoChimie_11a thermochemical database. Concentration of dissolved Am(III) in Syn-DB3 in the pH range of 6.4-10.5 was experimentally measured under over-saturation conditions by liquid scintillation counting over 70 d. The absorption spectra recorded for the same period suggest that Am(III) colloidal particles formed initially followed by rapid precipitation within 2 d. In the pH range of 7.5-10.5, the concentration of dissolved Am(III) converged to approximately 2×10-7 M over 70 d, which is comparable to that of the amorphous AmCO3OH(am) according to the modeling results. As the samples were aged for 70 d, a slow equilibrium process occurred between the solid and solution phases. There was no indication of transformation of the amorphous phase into the crystalline phase during the observation period.

Geochemical Dispersion and Enrichment of Fluvial Sediments Depending on the Particla Size Distribution (입도분포에 따른 하상퇴적물의 지구화학적 분산 및 부화)

  • 이현구
    • Economic and Environmental Geology
    • /
    • v.32 no.3
    • /
    • pp.247-260
    • /
    • 1999
  • Geochermical characteristics of the fluvial sediments deprnding on particle size distribution size were investigated in the respect of majir, minor and rare eath element chemisitry. Ratios of $Al_{2}O_{3}/Na_{2}O$ and $K_{2}O/Na_{2}O$ of the sediments show the homogeneous valus, and partly positive correlation with $SiO_{2}/Al_{2}O_{3}$, respecively. Characteristics of minor element ratios (V/Ni, Cr/V, Ni/Co and Zr/Hf)are within the lower and narrow range. Thesesuggested that sediment sources may be acidic to intermediate granitic rock, and may be explained by simple weathering and sedimentation. With increasing SiO2 contents, concentrations of $Al_{2}O_{3}$, $Fe_{2}O_{3}$, CaO and MgO decreased, but those of $K_{2}O$ and $Na_{2}O$ increased, Concentrations of Ba, Be, Cs, Cu, Li, Ni, Sr, V and Zr show comparatively normal negative and some positive trends. Compared with the mean composition of granite, concentrations of $Al_{2}O_{3}$, $Fe_{2}O_{3}$, MnO, CaO and MgO in the sediments of the study area were highly enriced. Among some minor and rare earth elements, concentrations of As, Cd, Cu, and V were enriched, but those of Be, Ce, Rb, Sc, Sr and Zn were depleted when compared with average composition of granite. By decreasing of particle size fractions, SiO2, Rb and Sr conterts decreased, but concentrations of $Al_{2}O_{3}$, $Fe_{2}O_{3}$, CaO, MgO, $TiO_{2}$, MgO, $P_{2}O_{5}$, Be, Cu, Hf, Pb, V and Zr increased. From the correlations between particle size fractions and element concenreations, some elements of $Fe_{2}O_{3}$, CaO, MgO, $P_{2}O_{5}$, Cu, Ni, Zn and Zr showed typical trends in the secondary contramination sediments. These trends are typically shown under 100 mesh fractions. It indicates that the fraction of minus 100 mesh is the optimum size fraction for geochemical and environmental survey.

  • PDF

A Parametric Study on the Sorption of U(VI) onto Granite (U(VI)의 화강암 수착에 대한 매개변수적 연구)

  • Min-Hoon Baik;Won-Jin Cho;Pil-Soo Hahn
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
    • /
    • v.2 no.2
    • /
    • pp.135-143
    • /
    • 2004
  • An experimental study on the sorption of U(VI) onto a Korean granite was performed as a function of the geochemical parameters such as contact time, pH, ionic strength, and carbonate concentration using a batch procedure. The distribution coefficient,$K_d$, was about 1-200 mL/g depending on the experimental conditions. The sorption of U(VI) onto granite particles was greatly dependent upon the contact time, pH, and carbonate concentration, but insignificantly dependent on the ionic strength. It was noticed that the sorption of U(VI) onto granite particles was highly correlated with the uranium speciation in the solution, which was dependent on the pH and carbonate concentrations. It was deduced from the kinetic sorption experiment that a two-step first-order kinetic behavior could dominate the kinetic sorption of U(VI) onto granite particles. In the alkaline range of a pH above 7, U(VI) sorption was greatly decreased and this might be due to the formation of anionic U(VI)-carbonate aqueous complexes as predicted by the speciation calculations.

  • PDF

Basic Research of the Paleo-Environmental Change and Possibility of Ancient Port Location Through Geomorphological Survey and Sediment Analysisin Hwaseong City (화성 당성 유적 일대의 지형 조사 및 퇴적물 분석을 통한 고환경 변화 및 고대 포구 입지 가능성 기초 연구)

  • Han, Min;Yang, Dong-Yoon;Lim, Jaesoo
    • Journal of The Geomorphological Association of Korea
    • /
    • v.24 no.4
    • /
    • pp.27-41
    • /
    • 2017
  • In this study, geomorphological and geological research has been carried out to estimate the possibility of ancient port location near Hwaseong Dangseong. Geomorphological characteristics around Eunsupo were analyzed through comparison of past and present topographic maps and field survey. Grain size, age dating, and geochemical analysis on surface sediments and borehole sediments were performed. Through the geomorphological characteristics analysis, it was interpreted that Eunsupo area was submerged in seawater especially at high tide in the past, and that ships could approach to the inside of the area through the tidal channel which were developed in the area. It is also assumed that ships were anchored at a low elevation point in the area. The paleo-environmental change in the area was analyzed based on the classification of sedimentary environment using grain size distribution of surface and borehole sediments and geochemical analysis. It was confirmed that the geomorphological interpretation for the possibility of ancient port location coincided well with the paleo-environmental change interpreted through sediment analysis. This study is a basic study for estimating ancient port location, and it is expected that more accurate paleo-environmental changes will be restored through detailed geomorphological survey and additional borehole analysis in the future research.

Stratigraphic Implication of the Daljeon Basalt in the Miocene Pohang Basin, SE Korea (한반도 동남부 마이오세 포항분지 내 달전현무암의 층서적 의미)

  • Song, Cheol Woo;Kim, Hyeonjeong;Kim, Jong-Sun;Kim, Min-Cheol;Son, Moon
    • The Journal of the Petrological Society of Korea
    • /
    • v.24 no.4
    • /
    • pp.323-335
    • /
    • 2015
  • Although the Daljeon Basalt in the Pohang Basin is important for interpreting the basin evolution, its relative chronology, stratigraphic position, and isotopic age still remain controversial. In order to clear up the controversies, this study carried out detailed field investigation to determine its distribution and occurrence together with reanalysis of its previous geochemical data and $^{40}Ar/^{39}Ar$ age dating. Based upon the field investigation, the basalt occurring in the central part of the Pohang basin is composed of three main bodies and a dozen of minor dikes and sills that intruded into the Yeonil Group. Their mineral assemblages consist of phenocrysts such as olivine and clinopyroxene and fine groundmasses of clinopyroxene, plagioclase, olivine, and opaque oxide, impling the porphyritic texture of alkaline basalt. All their geochemical data also show the similar geochemical characteristics in TAS, Zr-Ti, and REE/trace elements distribution diagrams. The samples are plotted on alkalic field in the total alkali-versus-silica diagram and show similar patterns to enrichment oceanic basalt or within plate basalt in trace elements. In addition, $^{40}Ar/^{39}Ar$ isochron age of 13.82Ma is obtained. These results indicate that the Daljeon Basalt is an alkaline intrusive rock belonging to the middle Miocene Yeonil Group.