• Title/Summary/Keyword: 황 동위원소

Search Result 79, Processing Time 0.028 seconds

Analytical Methodology of Stable Isotopes Ratios: Sample Pretreatment, Analysis and Application (안정동위원소비 분석 기법의 이해: 시료의 전처리, 분석 및 자료의 해석과 적용)

  • Kim, Min-Seob;Hwang, Jong-Yeon;Kwon, Oh-Sang;Lee, Won-Seok
    • Korean Journal of Ecology and Environment
    • /
    • v.46 no.4
    • /
    • pp.471-487
    • /
    • 2013
  • This review paper was written to provide background information as well as future application for aquatic ecologists interested in using stable isotope. Stable isotope techniques has proved to be an extremely useful to elucidate a lot of environmental and ecological problems. Stable isotopes have been used as possible tracers to identify sources, to quantify relative inputs in a system. When utilized carefully, stable isotope tools provides apparent advantages for the scientists to find out the processes of material cycles in various environments and energy flows in natural ecosystems.

Lead Isotopic Study on the Dongnam Fe-Mo Skarn Deposit (동남 스카른 광상에 대한 납 동위원소 연구)

  • Chang, Ho Wan;Cheong, Chang Sik;Park, Hee In;Chang, Byung Uck
    • Economic and Environmental Geology
    • /
    • v.28 no.1
    • /
    • pp.25-31
    • /
    • 1995
  • In Dongnam area, Cretaceous igneous rocks, such as diorite, porphyritic granite, and quartz porphyry intruded Paleozoic sedimentary rocks, such as Myobong slate and Pungchon limestone. The Dongnam Fe-Mo skarn deposits were imposed on the diorite(endoskarn) and the Myobong slate(exoskarn). The ore deposits consist mainly of magnetite and molybdenite with small amounts of sulfides, such as galena, sphalerite, pyrite, chalcopyrite, and pyrrhotite. The igneous rocks show nearly constant $^{206}Pb/^{204}Pb(18.80{\sim}19.06)$ and $^{207}Pb/^{204}Pb(15.71{\sim}15.72)$ ratios. Their $^{207}Pb/^{204}Pb$ ratios higher than the typical ratios of orogene suggest that the igeneous rocks were formed from lower crust(or mantle) - derived magma excessively contaminated by upper crustal materials such as high radiogenic Precambrian basement rocks. The lead isotopic compositions of the igneous rocks, the Pungchon limestone, and the ore minerals show a well defined linear in $^{206}Pb/^{204}Pb$ - $^{207}Pb/^{204}Pb$ plot. The lead isotopic compositions of the igneous rocks are similar to those of magnetite and galena, which were formed at early skarn stage and significantly lower than those of altered quartz porphyry, molybdenites, and pyrite, which were formed at late epithermal alteration stage. Considering the systematic variation of the lead isotopic compositions in the ore minerals according to hydrothermal stages, the variation may be due to a relative variation in surrounding rock(Pungchon limestone) involvement in hydrothermal ore solution leaching the surrounding rock. Therefore, the variation of the lead isotopic compositions in ore minerals can be modeled in terms of the mixing of the leads derived from the igneous rocks as low radiogenic source and the surrounding rock(Pungchon limestone) as high radiogenic source.

  • PDF

Sulfate reduction and sulfur isotopic fractionation in marine sediments (해양퇴적물내에서의 황산염 환원과 황의 안정동위원소 분화)

  • 한명우
    • Journal of Environmental Science International
    • /
    • v.2 no.1
    • /
    • pp.43-49
    • /
    • 1993
  • Concentrations of sulfate and 6-values of sulfate, $({\delta}^{34}SO_4_){pw}$, dissolved In pore waters were measured from the sediment cores of the two different marine environments : deep northeast Pacific (57-1) and coastal Kyunggi Bay of Yellow Sea (57-2) . Sulfate concentration in pore waters decreases with depth at both cores, reflecting sulfate reduction in the sediment columns. However, much higher gradient of pore water sulfate at 57-2 than 57-1 indicates more rapid sulfate reduction at 57-2, because of high sedimentation rate at the coastal area compared to the deep-sea. The measured 6-values, $({\delta}^{34}SO_4_){pw}$, follow extremely well the predicted trend of the Rayleigh fractionation equation. The range of 26.756 to 61.35% at the coastal core 57-2 is not so great as that of 32.4$\textperthousand$ to 97.8$\textperthousand$ at the deep-sea core 57-1. Despite greater graclient of pore water sulfate at 57-2, the 6-values become lower than those of the deep- sea core 57-1. This inverse relation between the 6-values and the gradients of pore water sulfate could be explained by the combination of the two subsequent factors : the kinetic effect by which the residual pore water sulfate becomes progressively enriched with respect to the heavy isotope of $^{34}S$ as sulfate reduction proceeds, and the intrinsic formulation effect of the Rayleigh fractionation equation in which the greater becomes the fractionation factor, the more diminished values of $({\delta}^{34}SO_4_){pw}$ are predicted.

  • PDF

REE and Sr-Nd Isotopic Composition of the Shelf Sediments around Jeju Island, Korea (제주도 주변 대륙붕 퇴적물의 REE와 Sr-Nd 동위원소 조성)

  • Kim, Tae-Joung;Youn, Jeungsu
    • Journal of the Korean earth science society
    • /
    • v.33 no.6
    • /
    • pp.481-496
    • /
    • 2012
  • REE, major and trace elements, and Sr-Nd isotopic ratios of surface sediments around Jeju Island were analyzed for identifying the origin of the sediments. The Chemical Index of Alteration (CIA) between 44.2 to 68.9 (av. 59.4) shows a similarity with the Huanghe sediment. The most sediments found within the study areas show a very similar chondrite-normalized REE pattern that has enriched LREE ($La_{(N)}/Sm_{(N)}$ >3) and small negative Eu anomaly, typically of average shales. The UCC-nornalized REE patterns of the southwestern offshore sediment samples show a very similar pattem with the Changjiang sediment with enriched in most REE and more convex REE pattern than those of the Huanghe and Keum rivers sediments, which indicates that the Changjiang River's suspended sediments have been transported into the western part of Jeju Island. The $^{87}Sr/^{86}Sr$ isotopic ratios vs ${\varepsilon}_{Nd}(0)$ values were thus used as a tracer to discriminate the provenance of sediments in the study area. Based on the discriminated diagram, it clearly showed that most sediments in the western and northwestern part were closely plotted with sediments of the Huanghe River. However, the sediments in the southwestern part near the Changjianf estuary were closely plotted with submerged delta sediments of the Changjiang River. In contrast, the sediment samples of the northeastern part showed discriminative figures from those of the Chinese rivers. It suggests that sediments around Jeju Island must be originated from diverse sources.

Hydrogeochemical, Stable and Noble Gas Isotopic Studies of Hot Spring Waters and Cold Groundwaters in the Seokmodo Hot Spring Area of the Ganghwa Province, South Korea (강화 석모도 지역 온천수와 지하수의 수리지구화학 및 동위원소 연구)

  • Kim, Kyu-Han;Jeong, Yun-Jeong;Jeong, Chan-Ho;Keisuke, Nagao
    • Economic and Environmental Geology
    • /
    • v.41 no.1
    • /
    • pp.15-32
    • /
    • 2008
  • The hydrochemical and isotopic (stable isotopes and noble gas isotopes) analyses for hot spring waters, cold groundwaters and surface water samples from the Seokmodo hot spring area of the Ganghwa province were carried out to characterize the hydrogeochemical characteristics of thermal waters and to interpret the source of thermal water and noble gases and the geochemical evolution of hot spring waters in the Seokmodo geothermal system. The hot spring waters and groundwaters show a weakly acidic condition with the pH values ranging from 6.42 to 6.77 and 6.01 to 7.71 respectively. The outflow temperature of the Seokmodo hot spring waters ranges from $43.3^{\circ}C\;to\;68.6^{\circ}C$. Relatively high values of the electrical conductivities which fall between 60,200 and $84,300{\mu}S/cm$ indicate that the hot spring waters were mixed with seawater in the subsurface geothermal system. The chemical compositions of the Seokmodo hot spring waters are characterized by Na-Ca-Cl water type. On the other hand, cold groundwaters and surface waters can be grouped into three types such as the Na(Ca)-$HCO_3$, Na(Ca)-$SO_4$ and Ca-$HCO_3$ types. The ${\delta}^{18}O\;and\;{\delta}D$ values of hot spring waters vary from -4.41 to -4.47%o and -32.0 to -33.5%o, respectively. Cold groundwaters range from -7.07 to -8.55%o in ${\delta}^{18}O$ and from -50.24 to -59.6%o in ${\delta}D$. The oxygen and hydrogen isotopic data indicate that the hot spring waters were originated from the local meteoric water source. The enrichments of heavy isotopes ($^{18}O\;and\;^2H$) in the Seokmodo hot spring waters imply that the thermal water was derived from the diffusion Bone between fresh and salt waters. The ${\delta}^{34}S$ values ranging from 23.1 to 23.5%o of dissolved sulfate are very close to the value of sea water sulfate of ${\delta}^{34}$S=20.2%o in this area, indicating the origin of sulfate in hot springs from sea water. The $^3H/^4He$ ratio of hot spring waters varies from $1.243{\times}10^{-6}\;to\;1.299{\times}10^{-6}cm^3STP/g$, which suggests that He gas in hot spring waters was partly originated from a mantle source. Argon isotopic ratio $(^{40}Ar/^{36}Ar=298{\times}10^{-6}cm^3STP/g)$ in hot spring waters corresponds to the atmospheric value.

Stable Isotopes of Ore Bodies in the Pacitan Mineralized District, Indonesia (인도네시아 파찌딴 광화대 함 금속 광체의 안정동위원소 특성)

  • Han, Jin-Kyun;Choi, Sang-Hoon
    • Economic and Environmental Geology
    • /
    • v.48 no.1
    • /
    • pp.15-24
    • /
    • 2015
  • Extensive base-metal and/or gold bearing ore mineralizations occur in the Pacitan mineralized district of the south western portions in the East Java, Indonesia. Metallic ore bodies in the Pacitan mineralized district are classified into two major types: 1) skarn type replacement ore bodies, 2) fissure filling hydrothermal ore bodies. Skarn type replacement ore bodies are developed typically along bedding planes of limestone as wall rock around the quartz porphyry and are composed mineralogically of skarn minerals, magnetite, and base metal sulfides. Hydrothermal ore bodies differ mineralogically in relation to distance from the quartz porphyry as source igneous rock. Hydrothermal ore bodies in the district are porphyry style Cu-Zn-bearing stockworks as proximal ore mineralization and Pb-Zn(-Au)-bearing fissure filling hydrothermal veins as distal ore mineralization. Sulfur isotope compositions in the sulfides from skarn and hydrothermal ore bodies range from 6.7 to 8.2‰ and from 0.1 to 7.9‰, respectively. The calculated ${\delta}^{34}S$ values of $H_2S$ in skarn-forming and hydrothermal fluids are 0.9 to 7.1‰ (5.6-7.1‰ for skarn-hosted sulfides and 0.9-6.8‰ for sulfides from hydrothermal deposits). The change from skarn to hydrothermal mineralization would have resulted in increased $SO_4/H_2S$ ratios and corresponding decreases in ${\delta}^{34}S$ values of $H_2S$. The calculated ${\delta}^{18}O$ water values are: skarn magnetite, 9.6 and 9.7‰; skarn quartz, 6.3-9.6‰; skarn calcite, 4.7 and 5.8‰; stockwork quartz, 3.0-7.7‰; stockwork calcite, 1.2 and 2.0‰; vein quartz, -3.9 - 6.7‰. The calculated ${\delta}^{18}O_{water}$ values decrease progressively with variety of deposit types (from skarn through stockwork to vein), increasing paragenetic time and decreasing temperature. This indicates the progressively increasing involvement of isotopically less-evolved meteoric waters in the Pacitan hydrothermal system. The ranges of ${\delta}D_{water}$ values are from -65 to -88‰: skarn, -67 to -84‰; stockwork, -65 and -76‰; vein, -66 to -88‰. The isotopic compositions of fluids in the Pacitan hydrothermal system show a progressive shift from magmatic hydrothermal dominance in the skarn and early hydrothermal ore mineralization periods toward meteoric hydrothermal dominance in the late ore mineralization periods.