• Economic and Environmental Geology
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• v.34 no.1
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• pp.71-88
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• 2001

The Geochemica] and isotope studies on the $CO_2$-rich water from the Shinchon area were carried out. The Shinchon $CO_2$-rich water belongs to Ca(Na)-$HCO_3$ type showing very high $P_{CO_{2}}$ ( $10^{-0.35}$ ~ $10^{0.29}$ atm) and TDS (835-3,144 mg/L). The results of geochemical and isotope analysis indicate that $CO_2$ gas is originated from the deep seated source such as mantle or magmatic gases. The $CO_2$-rich water was evolved by interaction with deep-seated granite and major water-rock interaction was dissolution of p]agioclase resulting high Na content of $CO_2$-rich water. Precipitation and dissolution of secondary calcite might be accompanied with the dissolution of plagioclase maintaining Na/Ca ratio. High contents of K and $SO_4$ indicate that the geochemical characteristics of $CO_2$-rich water were partially affected by interaction with upper sedimentary rock during uprising to surface. N03 and tritium contents suggest that the $CO_2$-rich water was mixed with low $CO_2$ groundwater at some locations. The oxygen-hydrogen isotopes show that all water samples were derived from meteoric waters and the $CO_2$-rich water was isotopically re-equilibrated with lighter $CO_2$ gas. Although some carbon isotope data show isotopically heavy values, carbon isotope data indicate that the $CO_2$ gas was possib]y derived by deep source.

• Ocean and Polar Research
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• v.38 no.4
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• pp.339-345
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• 2016

Stable water vapor isotopes have been utilized as a tracer for studying atmospheric global circulations, climate change and paleoclimate with ice cores. Recently, since laser spectroscopy has been available, water vapor isotopes can be measured more precisely and continuously. Studies of water vapor isotopes have been conducted over the world, but it is the early stage in south Korea. For vapor isotopes study, a cryogenic sampling device for water vapor isotopes has been developed. The cryogenic sampling device consists of the dewar bottle, filled with extremely low temperature material and impinger connected with a vacuum pump. Impinger stays put in the dewar bottle to change the water vapor which passes through the inside of impinger into the solid phase as ice. The fact that water vapor has not sampled completely leads to isotopic fractionation in the impinger. To minimize the isotopic fractionation during sampling water vapor, we have tested the method using a serial connection with two sets of impinger device in the laboratory. We trapped 98.02% of water vapor in the first trap and the isotopic difference of the trapped water vapor between two impinger were about 20‰ and 6‰ for hydrogen and oxygen, respectively. Considering the amount of water vapor trapped in each impinger, the isotopic differences for hydrogen and oxygen were 0.33‰ and 0.06‰, respectively, which is significantly smaller than the precision of isotopic measurements. This work can conclude that there is no significant fractionation during water vapor trapping.

• Economic and Environmental Geology
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• v.27 no.3
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• pp.219-229
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• 1994

The Sangra Pb-Zn deposit is located in the Gampo area. Most Cretaceous sedimentary rocks and Paleogene felsic intrusives in the study area have experienced intense propylitization. Such propylitization and Pb-Zn mineralization in ore veins are involved with the fluid having very low oxygen isotopic composition.Sulfurisotopic equilibrium temperature during the main Pb-Zn mineralization (late stage I) is calculated as $T=275^{\circ}{\sim}295^{\circ}C$. Oxygen and sulfur fugacity in late stage I fluid is estimated as $logfO_2=-34.4{\sim}-29.1$ and $logfS_2=-12.0{\sim}-8.2$ bars. It is inferred that the sulfur isotopic composition oflate stage I fluid was very high such as ${\delta}^{34}S_{{\Sigma}S}=+22.4{\sim}+22.5$‰ and the origin of sulfur was ocean water sulfate. Oxygen and hydrogen isotopic composition of water in ore-forming fluid was gradually increased and more abundantly affected by ocean water from early to late mineralization stage as follows; (late stage I) ${\delta}^{18}O_{H2O}=-7.2{\sim}-1.1$‰, ${\delta}D_{H2O}=-87{\sim}-84$‰, (stage II) ${\delta}^{18}O_{H2O}=-2.4{\sim}-0.8$‰, ${\delta}D_{H2O}=-39{\sim}-21$‰ (stage III) ${\delta}^{18}O_{H2O}=+0.7{\sim}+12.6$‰, ${\delta}D_{H_2O}=-49{\sim}-42$‰. The pH in ore-forming fluid was about 4.7 during late stage I and is thought to have been gradually decreased from late stage I to stage II mineralization.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.9 no.2
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• pp.64-72
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• 2004

We measured the vertical profiles of $O_2$, H$_2$S, and pH in sediment pore water beneath marine cage fish farms using a microsensor with a 25 ${\mu}{\textrm}{m}$ sensor tip size. The sediments are characterized by high organic material load. The oxygen consumption, hydrogen sulfide oxidation, and sulfate reduction rates in the microzonations (derived from the vertical distribution of chemical species concentration) were estimated by adapting a simple one-dimensional diffusion-reaction model. The oxygen penetration depth was 0.75 mm. The oxic microzonations were divided into upper and lower layers. Due to hydrogen sulfide oxidation within the oxic zone, the oxygen consumption rate was higher in the lower layer. The total oxygen consumption rate integrated with reaction zone depth was estimated to be 0.092 $\mu$mol $O_2$cm$^{-2}$ hr$^{-1}$ . The total hydrogen sulfide oxidation rate occurring within 0.7 mm thickness was estimated to be 0.030 $\mu$mo1 H$_2$S cm$^{-2}$ hr$^{-1}$ , and its turnover time in the oxic sediment layer was estimated to be about 2 minutes. This suggests that hydrogen sulfide was oxidized by both chemical and microbial processes in this zone. The molar consumption ratio, calculated to be 0.84, indicates that either other electron accepters exit on hydrogen sulfide oxidation, or elemental sulfur precipitation occurs near the $O_2$- H$_2$S interface. Total sulfate reduction flux was estimated to be 0.029 $\mu$mol cm$^{-2}$ hr$^{-1}$ , which accounted for more than 60% of total $O_2$ consumption flux. This result implied that the degradation of organic matter in the anoxic layer was larger than in the oxic layer.

• Economic and Environmental Geology
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• v.36 no.5
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• pp.329-338
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• 2003

The purpose of this study is to identify the temporal and spatial variation of stable isotopic compositions of surface waters and shallow ground waters at a local watershed(100$Km^2$) near the Muju area. For oxygen and hydrogen isotope analysis, water samples were collected from 19-22 sites during August, October 2001, through April 2002. Seasonal variation in the isotopic compositions of surface waters was clearly shown. However, the degree of such isotopic variation was highly attenuated in shallow ground waters because of mixing with preexisting ground waters. Isotope values of surface waters and ground waters were very similar in each season, indicating that precipitation/ground water/surface water interactions were very active and continuous in the watershed. Stable isotopic ratios of surface waters in the study area were lighter than those of the downstream reach of Geum River on south, indicating “latitude effect”. Both “altitude effect” and “amount effect” were also shown in the stable isotopic ratios of surface waters in the study area as well as seasonal variation of stable isotopes.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.41 no.2
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• pp.89-93
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• 2008

Goldfish were exposed to radioactive isotope $^{18}F$, which is used for positron emission tomography (PET). $^{18}F$ is created when the oxygen in water combines with hydrogen on exposure to positrons accelerated by a cyclotron. The temporal change in intestine contractility was measured by physiograph after the exposure to $^{18}F$. The distance between the goldfish and 580 mCi of $^{18}F$ was approximately 4 cm and the exposure was for 4 hrs. The absorption level calculated from the distance, exposure time, and half-life of $^{18}F$ was approximately 2 Gy. The contractile activity of goldfish intestine was lowest on the first day and increased gradually to 100% of the control level by a period of between 5 and 36 days.

• Journal of Soil and Groundwater Environment
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• v.26 no.1
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• pp.65-75
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• 2021

We investigated hydrochemical and stable isotope characteristics of groundwater in a large agricultural plain, the Honam plain, to evaluate the adequacy of agricultural water supply. For preliminary assessment for the area, we collected 23 groundwater samples from domestic wells and conducted hydrochemical and water stable isotope analysis. Groundwater in the study area is mainly Ca-HCO3 type resulting from water-rock interactions. Stable oxygen and hydrogen isotopic compositions indicated that recharge water is derived from precipitation while some sampling sites had evaporation signatures. Irrigation water quality using sodium absorption ratio and salinity hazard showed most of the groundwater samples were found to be suitable for irrigation. The groundwater in the southwestern part of the study area was affected by both seawater intrusion and agricultural activities, indicating a higher possibility of groundwater contamination near the coastal areas. Elevated concentrations of nitrate and phosphate ions in the groundwater are considered to be influenced by anthropogenic activities such as fertilizer application. It is expected that this study would be able to provide preliminary information on groundwater quality for agricultural water supply in the Mangyeong-Dongjin watershed.

• Economic and Environmental Geology
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• v.43 no.5
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• pp.443-453
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• 2010

The Samsung gold-silver deposit consists of quartz veins that fill along the fault zone within Cretaceous shale and sandstone. Mineralization is occurred within fault-breccia zones and can be divided into two stages. Stage I is main ore mineralization and stage II is barren. Stage I is associated with wall-rock alteration minerals(sericite, pyrite, chlorite, quartz), rutile, base-metal sulfides(pyrrhotite, pyrite, sphalerite, chalcopyrite, galena), and electrum. Stage II occur quartz, calcite and pyrite. Fluid inclusion data indicate that homogenization temperatures and salinities of stage I range from 145 to $309^{\circ}C$ and from 0.4 to 12.4 wt.% NaCl, respectively. It suggests that hydrothermal fluids were cooled and diluted with the mixing of meteoric water. The main deposition of base-metal sulfides and electrum occurred as a result of cooling and dilution at temperature between $200^{\circ}C$ and $300^{\circ}C$. Sulfur(9.3~10.8‰) isotope composition indicates that ore sulfur was mainly derived from a magmatic source as well as the host rocks. The calculated oxygen[-2.3~0.9‰(quartz: 0.3‰, 0.9‰, calcite: -2.3‰)] and hydrogen[-86~-76‰(quartz: -86‰, -82‰, calcite: -76‰)] isotope compositions indicate that hydrothermal fluids may be meteoric origin with some degree of mixing of another meteoric water for paragenetic time.

• Economic and Environmental Geology
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• v.42 no.6
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• pp.513-525
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• 2009

The Buyeong gold-silver deposit consists of quartz veins that fill along the NS fault zone within Cretaceous Goseong formation. Mineralization can be divided into hypogene and supergene stages. Hypogene stage is associated with hydrothermal alteration minerals such as sericite, pyrite, chlorite, epidote and sulfides such as pyrite, pyrrhotite, marcasite, sphalerite, chalcopyrite, galena and galenobismutite. Supergene stage is composed of malachite, goethite, chalcocite, and sphalerite oxide. Fluid inclusion data indicate that homogenization temperatures and salinities range from 112 to $340^{\circ}C$ and from 0.2 to 7.9 wt.% NaCl, respectively. Sulfur(3.2~3.9‰) isotope composition indicates that ore sulfur was derived from mainly magmatic source as well as partly host rocks. The calculated oxygen(4.3~6.0‰) and hydrogen(-60~-64‰) isotope compositions indicate that hydrothermal fluids may be meteoric origin with some degree of mixing of another meteoric water for paragenetic time.

• Economic and Environmental Geology
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• v.41 no.1
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• pp.1-14
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• 2008

The Bongsang gold-silver deposit consists of quartz veins that fill along the fault Bone within Cretaceous andesitic lapilli tuff. Mineralization is occurred within fault-breccia zones and can be divided into two stages. Stage I which can be subdivided into early and late depositional stages is main ore mineralization and stage II is barren. Stage I began with deposition of wall-rock alteration minerals and base-metal sulfides, and was deposited by later native silver, Ag-bearing tetrahedrite, polybasite and base-metal sulfides such like pyrite, sphalerite, chalcopyrite and galena. Fluid inclusion data indicate that homogenization temperatures and salinities of stage I range from 137 to $336^{\circ}C$ and from 0.0 to 10.6 wt.% NaCl, respectively. It suggests that ore forming fluids were cooled and diluted with the mixing of meteoric water. Also, temperature and sulfur fugacity deduced mineral assemblages of late stage I are $<210^{\circ}C\;and\;<10^{-15.4}$ atm, respectively. Sulfur(3.4%o) isotope composition indicates that ore sulfur was mainly derived from a magmatic source as well as the host rocks. The calculated oxygen{2.9%o, 10.3%o(quartz: 7.9%o, 8.9%o, calcite: 2.9%o, 10.3%o)}, hydrogen(-75%o) and carbon(-7.0%o, -5.9%o) isotope compositions indicate that hydrothermal fluids may be meteoric origin with some degree of mixing of another meteoric water for paragenetic time.