• Economic and Environmental Geology
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• v.38 no.2 s.171
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• pp.129-134
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• 2005

The $^{87}Sr/^{86}Sr$ ratios between water and biogenic material are similar in marine and lacustrine environment. Pb isotope ratios we, however, reported not to have been corresponding between the biological tissues and ambient water in aquatic system, contrary to the Sr isotope ratios. In order to explore the potential application of two isotopes as environmental tracers, we report here the isotopic compositions of strontium and lead of gastropod shell in fresh water in Jinan area. The $^{87}Sr/^{86}Sr$ ratios of carbonate shells of gastropod living in fresh stream water, are similar as that of ambient water but are different by sites. The different $^{87}Sr/^{86}Sr$ ratios of stream water between the sites is likely caused by the difference of the isotopic composition of Sr derived form rocks in the basin. In contrast, there is a distinct difference of the lead isotopic values between the water and the gastropod shell, suggesting that shell-fish available lead in aquatic system is different from dissolved lead in water. It is assumed that the majority of Pb in stream water is derived from atmospheric Pb accumulated on soil materials over years rather than from rock.

• Economic and Environmental Geology
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• v.28 no.1
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• pp.25-31
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• 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.

• The Journal of the Petrological Society of Korea
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• v.10 no.3
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• pp.157-171
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• 2001

This study investigated the effects of Pb/Tl ratio, Pb concentration and concomitant matrix elements on the measurement of Pb isotope ratios using multi-collector ICP/MS (AXIOM MC model). Accuracy and reproducibility of Pb isotope ratios in NBS 981 solution were estimated for 42 data measured from March to August 2001. Pb isotopes measured in rocks, bronzes and sediments were compared to data measured by TIMS. Reproducibilities for $^{206}Pb/^{204}Pb,\; ^{207}Pb/^{204}Pb,\;and\;^{208}Pb/^{204}Pb$ ratio were about 500 ppm (2sd) and for $^{207}Pb/^{206}Pb$\;and\;^{208}Pb/^{206}Pb$ were 100~200 ppm for 200 ng of Pb in NBS 981 solution. The optimum conditions for the analysis of Pb isotope ratios with AXIOM MC for best accuracy and reproducibility were defined as follows; 1) Pb/Tl ratio is about 10 2) Pb concentration is about 100 ng/ml 3) correction for mass discrimination is performed by exponential law using 2.3887 of $^{205}Tl/^{203}Tl$ and Pb mass fractionation factor empirically obtained from $ln(^{208}Pb/^{206}Pb)-ln(^{205}Tl/^{203}Tl)$ relationship. The sample data measured with MC/ICP/MS for acid-digested and chemically separated rock samples, and acid-digested bronze samples and sediment samples coincide with those of TIMS within analytical errors. Therefore, MC/ICP/MS is a rapid analytical technique for Pb isotope ratios with the similar precision compared with TIMS.

• The Journal of the Petrological Society of Korea
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• v.5 no.1
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• pp.84-88
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• 1996

Pb isotope composition is analyzed from the rock chips of marbles intercalated between gneisses of Muju area and it shows very large variation ($^{206}Pb/^{204}Pb$=23.74~4142, $^{207}Pb/^{204}Pb$=16.32~18.43, $^{208}Pb/^{204}Pb$=36.42~39.75). The data points form well defined positive relationship on $^{206}Pb/^{204}Pb$ vs $^{207}Pb/^{204}Pb$ plot, which corresponds to $1.99{\pm}0.10$($2{\sigma}$) Ga. This age is very similar to the formation ages of the granitic gneisses from Buncheon and Cheondongri (Tanyang), and suggests that the fairly large volume of Sobaeksan Massif suffered regional metamorphism at this time. It is suggested that the most parts of Korean peninsula including Kyeonggi and Sobaeksan Massifs were very close each other and experienced a regional metamorphism together about 2.0 Ga ago from the fact that galenas from whole Korean Peninsula except Kyeongsang Basin and metamorphic rocks from Kyeonggi Massif also reveal a similar slope corresponding 2.0 Ga on Pb-Pb isotope plot.

• Economic and Environmental Geology
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• v.28 no.1
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• pp.19-24
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• 1995

Based upon the lead isotopic compositions of the galenas collected from Pb-Zn ore deposits distributed in the eastern and southern parts of the Gyeongsang basin, we investigated what kinds of source materials were involved in the formation of these ore deposits and compared the lead isotopic characteristics of these ore deposits with those of the ore deposits in the Taebaegsan area. The isotopic compositions of the common leads from Pb-Zn ore deposits in the Gyeongsang basin show the variation with the relatively limited range ($^{206}Pb/^{204}Pb=18.156{\sim}18.377$, $^{207}Pb/^{204}Pb=15.482{\sim}15.638$, and $^{208}Pb/^{204}Pb=37.953{\sim}38.605$). They are plotted on or below ore lead growth curve(Cumming & Richards, 1975) and average crustal lead evolution curve (Stacey & Kramer, 1975). In the plumbotectonic model IV(Zartman & Haines, 1988), they are plotted between the evolution curves of mantle and orogene. But the lead isotopic compositions of the common leads in the Taebaegsan area are plotted on and above upper crust curve. Considering the above-mentioned lead isotopic characteristics, the linear trend shown in the isotopic compositions of the common leads in the Gyeongsang basin can be considered as the mixing isochron between high radiogenic crustal materials such as the Ryongnam massif and low radiogenic materials derived from depleted mantle or materials with relatively low U/Pb and Th/U ratios.

• Journal of Korean Society of Environmental Engineers
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• v.33 no.3
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• pp.174-182
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• 2011

The present study evaluated the major lead sources in a steel metallurgy industrialized city by measuring lead isotopes/lead concentrations of ambient air and potential sources in an industrial area and residential areas according to relative distance. The quality control program obtained during the measurement procedure for lead isotopes and concentrations exhibited $0.5ng/m^3$ for method detection limit, more than 90% for recoveries of standard particulate matters, and lower than 0.2% for reproducibility errors of four lead isotopes ($^{204}Pb$, $^{206}Pb$, $^{207}Pb$, $^{208}Pb$). For all three lead isotope ratios ($^{206}Pb/^{204}Pb$, $^{207}Pb/^{206}Pb$, $^{208}Pb/^{206}Pb$), the ratios were obtained in the industrial area were closer to nearby residential area than those of a residential area far away from the industrial area, thereby suggesting that lead sources were more similar each other in the industrial and nearby residential area. Furthermore, for both summer and winter seasons ambient lead concentrations were more than four times higher in the industrial area than in the residential areas and in turn, they were higher in the nearby residential area compared with the far-away residential area. As a result, it was suggested that lead emitted from the industrial area would influence more the ambient lead in the nearby residential area than the far-away residential area. Both slag and traffic emissions are likely to be major lead sources in the industrial and nearby residential areas, since their three lead isotope ratios ($^{206}Pb/^{204}Pb$, $^{207}Pb/^{206}Pb$, $^{208}Pb/^{206}Pb$) were similar to the ratios obtained from ambient air of these two areas. In addition, the lead isotope ratios revealed different pattern between seasons, and the ambient lead concentrations were higher for winter than for summer.

• The Journal of the Petrological Society of Korea
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• v.9 no.2
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• pp.53-69
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• 2000

To reveal the origin of the Chuncheon nephrite deposit, radiogenic isotopes of Sr and Pb, stable isotopes of 0 and H, and rare earth elements concentrations were analyzed. Such geochemical data were integrated to track the stepwise changes during the various ore formation stages. All the samples from the nephrite deposit have significantly low 0 isotopic ratios compared with the marble from which they had been formed, which reflects the very important role of the crustal circulating water with low 6180 and 6D in every stage of ore formation. There were progressive decrease of 6180 and 6D during the genesis of Chuncheon nephrite deposit. Newly formed minerals during the ore formation reveal disequilibrium with existing minerals in the respect of 0 isotope, which suggests that the ore-forming fluid of circulating water origin was involved with significant water-rock ratios in every step of ore formation process. The ore samples have Sr and Pb isotopic ratios similar to the values of Kyeonggi gneiss complex within which the deposit is located, which also suggests the important role of crustal circulating water in the genesis of the deposit. In conclusion, all the geochemical data support that major portion of the ore-forming fluid of Chuncheon nephrite deposit was derived ultimately from the surface water of meteoric origin. The meteoric water supplied Sr and Pb through leaching the rocks surrounding the ore deposits.

• 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.

• Economic and Environmental Geology
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• v.56 no.4
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• pp.475-499
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• 2023

To infer the provenance of raw iron materials utilized in iron production at the archaeological sites in Gyeongsang province, petrographic and geochemical analyses were conducted for smelting samples and major iron ores sourced from ore deposits. The smelting samples excavated from various iron archaeological sites were classified into different types according to their refining processes, such as iron bloom, iron bloom slag, pig iron, pig iron slag, forging iron flake, smithery iron, iron flake, and arrowhead. These samples exhibited discernable differences in their mineralogical components and texture. The enrichments of major elements such as aluminum and calcium in silicate minerals of the residual slags and the high contents of trace elements such as nickel and copper in some iron-making relics reflect the characteristics of raw iron ores, and thus can be regarded as potential indicators for inferring the provenance of source materials. In particular, the compositional ranges of Pb-Sr isotope ratios for the iron smelting samples were classified into three categories: 1) those exhibiting similar ratios to those of the raw iron ores, 2) those enriched in strontium isotope ratio, and 3) those enriched in both lead and strontium isotope ratios. The observed distinct Pb-Sr isotope characteristics in the iron smelting samples suggest the potential contribution of specific additives being introduced during the high-temperature refining process. These results provide a new perspective on the interpretation of the provenance study of the iron archaeological samples in Gyeongsang province, particularly in terms of the potential contribution of additives on the refining process.

• The Journal of the Petrological Society of Korea
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• v.25 no.1
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• pp.51-67
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• 2016

Geochemical characteristics of the Early Cretaceous igneous rocks from eastern China and the Gyeongsang Basin, Korean Peninsula has been summarized. They have wide range of lithological variation with extrusive picrite-basalt-andesite-trachyte-rhyolite and lamprophyre, and intrusive gabbro-diorite-monzonite-syenite-granite and diabase in eastern China, mostly belonging to the high-K calc-alkaline or shoshonitic series. The volcanic rocks intercalated with the Hayang Group sedimentary assemblages in the Gyeongsang basin are high-K to shoshonitic basaltic trachyandesites. The Early Cretaceous basaltic rocks studied mostly fall within the field of within-plate basalts on the Zr/Y-Zr and Nb-Zr-Y tectonic discrimination diagrams. On a Sr-Nd isotope correlation diagram, basaltic rocks from the North China block (NCB) and the continent-continent collision zone (CZ) between the North and South China blocks plot into the enriched lower right quadrant along the extension of the mantle array. The initial $^{87}Sr/^{86}Sr$ ratios of basaltic rocks from the South China block (SCB) are indistinguishable from those of the NCB and CZ basaltic rocks, but their ${\varepsilon}_{Nd}$ (t) values are relatively more elevated, plotting in right side of the mantle array. Basaltic rocks from the NCB and CZ are characterized by low $^{206}Pb/^{204}Pb(t)$ ratios, lying to the left of the Geochron on the $^{207}Pb/^{204}Pb(t)$ vs. $^{206}Pb/^{204}Pb(t)$ correlation. Meanwhile, the SCB basaltic rocks have relatively radiogenic Pb isotopic compositions compared with those of the NCB and CZ basaltic rocks. Basaltic rocks from the Hayang Group plot within the field of the NCB basaltic rocks in Sr-Nd and Pb-Pb isotope spaces. Metasomatically enriched subcontinental lithospheric mantle (SCLM) is likely to have been the dominant source for the early Cretaceous magmatism. Asthenospheric upwelling under an early Cretaceous extensional tectonic setting in eastern China and the Korean Peninsula might be a heat source for melting of the enriched SCLM. Metasomatic agents proposed include partial melts of lower continental crust delaminated and foundered into the mantle or subducted Yangtze continental crust, or fluid/melt derived from the subducted paleo-Pacific plate.