• Journal of the korean society of oceanography
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• 제32권1호
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• pp.28-37
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• 1997

Two marine bivalve shells were collected from the eastern and western coastal regions of Korea, respectively. Stable oxygen and carbon isotope profiles are constructed using the incremental sampling along the axis of maximum growth to provide the continuous ${\delta}^{18}$O and ${\delta}^{13}$C records, which register the physical, biological and chemical properties of seawater where the organisms live. Cycles in the ${\delta}^{18}$O profiles are interpreted as annual along with the identification of annual growth bands; the maximum ${\delta}^{18}$O values correspond with the coldest temperature of seawater whereas the minimum ${\delta}^{18}$O values with the warmest temperature. The primary control on the amplitude of the ${\delta}^{18}$O profiles is seasonal variation of seawater temperature. The offset of the baseline between ${\delta}^{18}$O values of the two specimens is attributed to differences in both temperature and seawater ${\delta}^{18}$O values between two localities. The ${\delta}^{13}$C profiles show the similar seasonality of carbon cycling associated with phytoplankton productivity. The offset in the ${\delta}^{13}$C profiles between two specimens may be, as in the case of oxygen isotope profile, attributed to the different ${\delta}^{13}$C value of the seawater DIC (dissolved inorganic carbon) between the western coast and the eastern coast. Relationships between the shell isotopic composition and the coastal water properties of shell growth are readily interpreted from the ${\delta}^{18}$O-${\delta}^{13}$C pair diagram of the shell isotope data, similar to the use of salinity-${\delta}^{18}$O diagram for identifying water masses. The preliminary stable isotope results of this study suggest that mollusk shell isotope geochemistry may be useful to monitor the properties of water masses in the coastal and inner shelf setting around Korea and improve the interpretation of paleoceanography, provided the fossil mollusks are well preserved.

• 한국석유지질학회지
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• 제13권1호
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• pp.24-29
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• 2007

본 연구의 주요 목적은 대한해협 대륙붕 이토대 지역의 천부 공기층 가스의 기원을 규명하는데 있다. 채취한 시료의 공기층 가스 분석 결과에 의하면 천부 공기층 가스의 대부분은 메탄으로 구성되어 있으며, 메탄 내 탄소 및 수소 동위원소 값은 각각 $-93.4%o{\sim}-70.9%o{\sim}\;-228%o{\sim}-199%o$ 가진다. 이러한 분석결과는 천부 공기층 가스 내 메탄가스가 열기원(thermogenic) 가스보다는 이산화탄소 환원작용($CO_2$ reduction)에 의한 생물 기원(biogenic) 가스임을 지시한다. 또한 메탄과 이산화탄소의 탄소 동위원소비 차는 54.4에서 72.2의 범위를 가지고 있으며, 이러한 결과 역시 전기한 결과를 뒷받침하는 또 다른 증거이다.

• 자원환경지질
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• 제28권2호
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• pp.123-137
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• 1995

The Mesozoic Geumsan granitic rocks of various composition are distributed in the Geumsan district, the central part of the Ogcheon Fold Belt. About 40 ore deposits of $CaF_2{\pm}Au{\pm}Ag{\pm}Cu{\pm}Pb{\pm}Zn$ are widely distributed in this district and are believed to be genetically related to the granitic rocks. Based on their petrography and geochemistry, the granitic rocks in this district can be classified into two groups ; the Group I( equigranular leucocratic granite, porphyritic biotite granite, porphyritic pink-feldspar granite, seriate leucocratic granite) and the Group II(seriate pinkfeldspar granite, equigranular alkali-feldspar granite, equigranular pink-feldspar granite, miarolitic pink-feldspar granite, equigranular biotite granite). Interpreted from their isotopic dating data and geochemical characteristics, the Group I and the Group II are inferred to be emplaced during the Jurassic(~184Ma), and the Cretaceous to the early Tertiary period(~59Ma), respectively. Both Group I and Group II generally belong to magnetite-series granitoids. The Cretaceous granitic rocks of Group II are more highly evolved than those of the Jurassic Group I. The Rb-Sr variation diagram suggests that the granitic rocks of the Jurassic Group I and of the Cretaceous Group II be evolved mainly during the processes of fractional crystallization and partial melting, respectively.

• 지질공학
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• 제30권3호
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• pp.303-314
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• 2020

먹는샘물 제조업체의 경우 주기적인 환경영향조사, 일취수량 제한, 그리고 취수량 및 수위, 수질(pH, EC, 온도)을 1시간 간격으로 계측하여 매월 보고하고, 정기 수질검사 등을 통해 엄격히 관리하고 있어 과잉 취수로 인한 지하수위 강하와 같은 문제가 발생하는 사례가 적으나 제조업체 주변 지하수관련 민원의 원인 제공자로 각인되고 있는 실정이다. 그러므로 환경영향조사의 물수지 분석 시 수문분야 전문가들의 평가에 부합하고, 비전문가에게도 쉽게 접근할 수 있는 기법의 제시가 필요하다고 판단된다. 따라서 샘물 취수정이 위치한 소유역의 지표수 수위 및 유출량을 측정하고 상시하천의 월별 기저유출량을 분리하였다. 또한 동일 유역의 지하수(취수정), 지표수, 강수의 산소, 수소 동위원소를 분석하여 지하수와 지표수의 함양특성에 관하여 추정하였다.

• Journal of Ecology and Environment
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• 제36권3호
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• pp.183-191
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• 2013

Dissolved organic carbon (DOC) concentrations and zooplankton and particulate organic matter (POM) ${\delta}^{13}C$ values were measured in five reservoirs in Korea. Zooplankton ${\delta}^{13}C$ and POM ${\delta}^{13}C$ showed large range from -33‰ to -22‰ and a significant difference among the reservoirs. One eutrophic reservoir, Lake Masan, showed unique characteristics with the highest zooplankton density, the highest ${\delta}^{13}C$, and the highest DOC. Zooplankton ${\delta}^{13}C$ was similar to POM ${\delta}^{13}C$, implying that zooplankton occupies substantial portion of POM or that zooplankton isotopic composition is related to selective grazing and assimilation of food sources from bulk POM. Except Lake Masan zooplankton ${\delta}^{13}C$ values were negatively correlated to DOC concentration in four reservoirs with mostly forest land use. This pattern can be probably attributed to intensive agricultural land use in the watershed of Lake Masan compared to the mostly forest land use in the other watersheds. Understanding the relationship between zooplankton ${\delta}^{13}C$ values and the origin of organic matter associated with watershed characteristics will be valuable to better understand trophic relationships in reservoirs in the summer monsoon region.

• 자원환경지질
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• 제18권3호
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• pp.247-251
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• 1985

The sulfide and carbonate mineral samples for sulfur and carbon isotope studies were collected from Sangdong, Geodo, Yeonhwa, Shinyemi and Janggun mines which are distributed in the Metallogenetic Province of the Taebaeg Mt. Region. The ${\delta}S^{34}$ values of molybdenite, pyrite, arsenopyrite, pyrrhotite, chalcopyrite, sphalerite and galena from the above mines are similar and within the range of +1.66 to +6.77‰ with the exception of chalcopyrite from Geodo mine ranging from -1.58 to 1.96‰, while the sulfide minerals are dominated by positive values between +3.05 and +5.08‰. It is suggested that the major sulfur source is genetically related to the Cretaceous granitic activity. The average ${\delta}C^{13}$ values of calcite from limestone, calcite from calcite vein in ore bodies and granite, and rhodochrosite from ore bodies are -0.60‰, -2.69‰ and -6.00‰, respectively. The data on carbon isotope compositions indicate that the calcite from limestone originated in marine environment, the rhodochrosite in hydrothermal solution, and calcite from calcite vein and granite in the mixing condition of marine and hydrothermal waters. The temperatures of mineralization by the sulfur isotopic composition coexisting pyrite-pyrrhotite from Yeonhwa No.1, sphalerite-galena from Weolam and Dong-jeom of Yeonhwa No.1 mine, sphalerite-galena and pyrite-galena from Janggun mine were $273^{\circ}C$, $460{\sim}511^{\circ}C$, $561{\sim}690^{\circ}C$, $341^{\circ}C$ and $375^{\circ}C$, respectively.

• 한국해양학회지
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• 제30권2호
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• pp.69-76
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• 1995

오끼나와 해곡의 남쪽 해저 2051 m에서 채취된 저탁류 퇴적물(RN88-PC5)에 대하여 조사하였다. 반원양성 점토질 퇴적물과 천해에서 운반된 사질퇴적물 사이에는 저저성 유공충의 조성, 입도조성 및 화학적 원소의 조성 등에서 현저한 퇴적학적 특성의 차이 를 보인다. 저탁류 퇴적물인 사질퇴적물에 있어서는 점토질 퇴적물에는 포함되어 있지 않은 전형적인 신호초 해역의 유공충을 다량으로 함유하고 있는 것으로 보아 천해에서 유입된 퇴적물임이 거희확실하다. 이들 사질퇴적물은 저탁류와 관련되어 운반 되었으 며, 사질퇴적물과 점토질퇴적물 사이에는 다른 퇴적학적인 기작이 작용되었음을 시사 한다. /SUP 14/C 연대측정 결과와 유공충의 안정 산소동위원소값의 변화는 과거 약 1 만년으로부터 현재에 이르기까지 포층해수의 점진적인 온난화 경향을 보인다. 또한 Termination 1b의 기록을 보일 뿐만 아니라 약 2천년전과 7천년전의 2회에 걸친 담수 유입의 증거도 보여진다.

• Ocean and Polar Research
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• 제41권3호
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• pp.159-168
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• 2019

Understanding the interaction between climate and the water cycle is critical especially in a drought sensitive region such as California. This study explored hydrologic changes in central and southern California in relation to the glacial-interglacial climate cycles over the last 30 thousand years. To do this, we reconstructed paleovegetation using plant wax carbon isotopic compositions (${\delta}^{13}C$) preserved in marine sediment cores retrieved from the central California continental shelf (ODP Site 1018) and Santa Barbara Basin (ODP Site 893A). The results were then compared to the existing sea surface temperature (SST) and pollen records from the same cores to understand terrestrial hydrology in relation to oceanographic processes. The Last Glacial was generally dry both in central and southern California, indicated by grassland expansion, confirming the previously suggested notion that the westerly storm track that supplies the majority of the precipitation in California may not have moved southward during the glacial period. Southern California was drier than central California during the Last Glacial Maximum (LGM). This drying trend may have been associated with the weakening of the California Current and northerly winds leading to the early increase in SST in southern California and decline in both offshore and coastal upwelling. The climate was wetter during the Holocene in both regions compared to the glacial period and forest coverage increased accordingly. We attribute this wetter condition to the precipitation contribution increase from the tropics. Overall, we found a clear synchronicity between the terrestrial and marine environment which showed that the terrestrial vegetation composition in California is greatly affected by not only the global climate states but also regional oceanographic and atmospheric conditions that regulate the timing and amount of precipitation over California.

• 환경분석과 독성보건
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• 제21권4호
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• pp.237-242
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• 2018

Strontium (Sr) commonly exists in rock, groundwater, soil, plants, and animals. The Sr isotope ratio offers important information as a tracer on nature because the Sr isotopic composition is not fractionated by any biological process in these ecosystems. Hence, Sr isotope ratio has been used in several studies on tracing the Sr source for contaminated sites and human migration. In this study, we developed a separation method for Sr content, and then improved Sr isotope analysis using multi-collector inductively coupled plasma mass spectrometry (MC-ICP-MS). A powdered rock standard (NIST 2710a) was used to determine the removal of interference elements (Rb and Ca) and the recovery rate of Sr content. The results ranged from 98% to 106%. Additionally, three standard samples (NBS 987, IAPSO and NIST 1486) were analyzed to evaluate the precision and accuracy of the results. The measured $^{87}Sr/^{86}Sr$ ratio for all the samples were consistent with the reported values, within an error. These results indicate that our established Sr separation and Sr isotope measurement methods are reliable and can hence be useful in the fields of environmental and forensic sciences.

• 지질공학
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• 제21권1호
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• pp.65-77
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• 2011

본 연구에서는 경북 봉화지역, 강원도 오대산 및 춘천지역에서 산출되는 8개 탄산약수터에서 11개 탄산약수 시료를 대상으로 수리화학적 특성을 규명하고, 용존무기탄소의 동위원소(${\delta}^{13}C_{DIC}$)분석을 통해 탄산가스의 기원을 해석하며, 영족기체 동위원소($^3He/^4He$, $^{20}Ne/^{22}Ne$)의 동위원소 존재비를 분석하여 탄산가스의 기원과 연계한 영족기체의 기원을 밝히고자 하였다. 연구결과 탄산약수의 수리화학적 특성은 pH 5.59~6.04 범위로 약산성의 특성을 보이고, 전기전도도 값은 $302{\sim}864\;{\mu}S/cm$ 범위를 보인다. 모든 탄산약수의 수리화학적 유형은 Ca-$HCO_3$ 형에 속한다. 특히 Fe, Mn의 함량이 높아 음용수 수질기준치를 초과한다. 연구지역 탄산약수의 ${\delta}^{13}C_{DIC}$ 값은 -2.84~5.3‰ 범위를 보이므로 $CO_2$의 기원은 주로 심부기원이며, 물-암석 반응과정에서 탄산염광물등의 영향을 일부 받은 것으로 해석된다. 탄산약수의 $^3He/^4He$ 동위원소비와 $^4He/^{20}Ne$동위원소비 상관관계에서 탄산약수는 기원상 3개의 군으로 분류된다. 맨틀과 같은 심부기원의 영역, 대기기원에 가까운 영역, 맨틀기원과 대기기원의 혼합영역으로 도시된다. 이는 심부기원의 영족기체가 천부지하수와 지표노출에 의해 대기기원과 혼합된 것으로 해석되며, 맨틀과 같은 심부기원의 헬륨가스의 공급은 지질경계 및 단층과 같은 지질구조와 밀접한 관계가 있는 것으로 추정된다.