• Korean Journal of Environmental Biology
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• v.22
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• pp.93-102
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• 2004

A total of 110 surface sediment were analyzed in order to understand the geochemical eharacteristics of the surface sediments and to evaluate the benthic environmental condition of Gwangyang Bay. The surface sedimentary distribution can be classified by five facies; mud (M), sandy mud (sM), sand (S), muddy sand (mS) and gravely sand mud ((g)sM). However, mud face is the predominant sedimentary feature of the Gwangyang Bay. The benthic environment based on total organic carbon/total nitrogen (C/N) and total organic carbon/total sulfur (C/S) ratios of organic matter showed that anoxic environment is prevailed in some parts of the study area because the C/S ratio of organic matter was higher than 2.8. The hydrogen sulfide (H$_2$S) content showed extreme variability from site to site. It varies from 307 ppm to 1 ppm (average, 92 ppm). The inter-relationship of redox-sensitive elements (Mn, V, Mo and Cr) showed a relatively strong positive relationship with high accumulation in the sediment at the inner sites of the Bay (left of Myo Island). High content of TOC and hydrogen sulfide, and a high accumulation rate of redox- sensitive element were predominant characteristics in the sediments at the inner sites of the Bay (left of Myo Island), suggesting that this area is in an oxygen deficient, and potentially polluted condition.

• The Journal of the Petrological Society of Korea
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• v.26 no.2
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• pp.113-125
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• 2017

We investigates geochemical and tectonic characteristics for the Triassic Bojangsan trachyte in the southern margin of the Imjingang belt. The geochemical signatures of the thracyte are characterized by enrichments of REE and HFS, and show no Nb trough, suggesting that would not experience arc magmatic processes involving continental crustal materials. The trachyte reveals within-plate setting in tectonic discrimination diagrams using immobile HFS Nb and Y elements. And the trachyte shows typical signatures of A-type volcanic rocks with high Ga abundance and is classified as A1-type volcanic rocks rich in Nb. The geochemical signatures suggest that the trachyte was produced by the differentiation of mantle-derived magmatism at the continental rift in extensional setting subsequent to a major collision during the Permo-Triassic Songrim orogeny. The results provide robust evodence to consider the Imjingang belt as an extension of the the Qinling-Dabie-Sulu belt between the North and South China blocks.

• Economic and Environmental Geology
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• v.44 no.1
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• pp.21-35
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• 2011

Inorganic and organic geochemical characteristics of Devonian bitumen carbonates in Alberta were studied using two drilling cores, Saleski 03-34-88-20w4 and Saleski 08-01-88-20w4, taken from the Core Research Center of Canada. The results of elements analyses showed high Total Inorganic Carbon, low Total Nitrogen and Total Sulfur, and Rock-Eval pyrolysis showed double $CO_2$ peaks in the oxidation part. These mean that the Devonian bitumen carbonates are mainly composed of dolomite formed by diagenesis, and its crystal texture is dominantly subhedral to anhedral but often euhedral. Bitumen contents were 3.6~19.0% in Saleski 3-34-88-20w4 and 5.0~16.4% in Saleski 08-01-88-20w4, respectively. As samples color become dark, bitumen and Total Organic Carbon contents are generally increasing in two cores. The results of biomarker analyses showed that the contents of resins and asphaltenes were 5~28% higher than those of saturated hydrocarbon, interring that the bitumen has been heavily biodegradated. According to the results of carbon isotope analyses in each component of bitumen, asphaltenes had highest values and the others had constant values. However, their values were varied in the range of normal crude oil (-18~-30‰).

• The Korean Journal of Petroleum Geology
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• v.5 no.1_2 s.6
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• pp.48-58
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• 1997

Core samples from the B, E, F, H wells in the Tertiary Pohang Basin were analysed for total organic carbon (TOC) content and subject to Rock-Eval pyrolysis in order to assess petroleum geochemical characteristics of organic matter. Following geochemical screening, we selected samples from each well for the study of bitumen and kerogens such as optical observation, infra-red spectroscopy and biomarker analyses. Sediments of the Tertiary Yonil Group contain total organic carbon ranging from $0.55{\%} to 3.74{\%}$ with S1+S2 values higher than 2mgHC/g Rock in B, E and F wells, which indicates fair hydrocarbon generation potential. Most organic matter in the B, E, F wells is compared to type II based on the Rock-Eval pyrolysis, infra-red spectroscopy and optical observation. However, organic matter in the H well is compared to type III because the well is located at the margin of the basin where the preservation of terrestrial material is dominant. Geochemical analyses show that organic matter in the Yonil Group is thermally immature although thermal maturity slightly increases with depth. Maturity levels of the extracted kerogens are similar to those of bulk samples ($Tmax<435^{\circ}C$. Petroleum geochemical charateristics of the sediments in the Tertairy Yonil Group is fair in terms of the organic richness and hydrocarbon genetic potential, but organic matter is thermally immature due to the shallow burial depth. Optical observation of the kerogens and biomarker analysis show that organic matter in the Yonil Group is both marine and terrestrial origin, although it was deposited in marine environment. Pristane/phytane ratio suggests rather anoxic depositional environment. Transitional characteristics of organic matter indicate that the marine Yonil Group was deposited near the terrestrial environments. Input of terrestrial organic matter is more prevalent in the samples recovered from the lowermost horizon in the wells due to the terrestrial environment at the time of basin formation.

• Economic and Environmental Geology
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• v.56 no.5
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• pp.565-580
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• 2023

In this study, we reviewed and summarized comprehensive roles and importance of natural analogue studies for demonstrating the safety and improving the reliability of the safety for the deep geological disposal of high-level radioactive waste. We also investigated domestic and foreign status of natural analogue studies in order to study and substantiate complex and various radionuclide behaviors in subsurface disposal environments. In addition, we investigated and uranium behaviors in groundwater and rock in uranium deposits including domestic uranium deposits in Ogcheon Metamorphic Belt and biogeochemical interactions in geological environments. Although there are many limitations and uncertainties in directly using the information and data for uranium behaviors obtained from uranium deposits in the disposal safety assessment, the information and data can be utilized in the disposal safety assessment and safety case construction both in qualitative and partly quantitative ways.

• Journal of the Korean earth science society
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• v.24 no.5
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• pp.420-427
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• 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.

• Economic and Environmental Geology
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• v.36 no.3
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• pp.177-189
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• 2003

The main purposes of this study are to utilize mineralogical studies such as optical microscope, XRD and SEM/EDS analyses to characterize the oxidation of sulfide minerals and the mechanisms controlling the movement of dissolved metals from waste rocks at the abandoned Seobo mine. Mineralogical research of the waste rocks confirms the presence of anglesite, covellite, goethite, native sulfur and nsutite as secondary minerals, suggesting that these phases control the dissolved concentrations of As, Cu, Fe, Mn, Pb and Zn. The dissolved metals are precipitated, adsorbed and/or coprecipitated with(or within) Fe(Mn)-hydroxides and Mn(Fe)-hydroxides. The main phases of secondary mineral, Fe-hydroxide, can be classified as amorphous or poorly crystalline and more crystallized phases(e.g. goethite) by crystallinity. Amorphous or poorly crystalline Fe-hydroxide has relatively high As contents(9-24 wt.%). This poorly crystalline Fe-hydroxide changes toward more crystallized phase(e.g. goethite) which contains relatively low As(0.6-7.7 wt.%). These results are mainly due to the progressive release of As with the crystallization evolution of the As-trapping poorly crystalline Fe-hydroxides. It is also attributed to the differences of specific surface areas between the poorly crystalline Fe-hydroxides and well crystallized phases. The dissolved metals from waste rocks at Seobo mine area are naturally attenuated by a series of precipitation(as Fe, Mn, Cu, Pb), coprecipitation(Fe, Mn) and adsorption(As, Cu, Pb, An) reactions. The results of mineralogical researches permit to assess the environmental impacts of mine waste rocks in the areas, and can be used as a useful data to lay available mine restoration plan.

• Economic and Environmental Geology
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• v.38 no.2 s.171
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• pp.113-127
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• 2005

Cretaceous intrusive and extrusive rocks are widely distributed in the southwestern part of the Korean peninsula, possibly the result of intensive magmatism which occurred in response to subduction of the western proto-Pacific plate beneath the north-eastern part of the Eurasian plate. Geochemical and petrological study on the Cretaceous granitic rocks were carried out in order to constrain the petrogenesis of the granitic magma and to establish the paleotectonic environment of the area. Whole rock chemical data of the granitic rocks from the study area indicate that the all the rocks have characteristics of calc-alkaline series in the subalkaline field. The overall geochemical features show systematic variations in each granitic body, but the source materials of each granitic body are thought to have been different in their chemical composition. Higher values of $Fe_2O_3/FeO$ of the granitic rocks in the western area suggest that the granitoids had been solidified under highly oxidizing environment. The granitic bodies in the eastern area also show higher contents of Li, Ni, Co, Sr, Cr, Sc and lower Rb and Nb compared to the those of the western area. Chondrite normalized REE patterns show generally enriched LREE and strong negative Eu anomalies in the western wet while slight to flat Eu anomalies in the east-ern area. The REE and $(La/Lu)_{CN}$ of the granites are $60{\~}499ppm$ and $8.9{\~}66$ correspond to the range of the continental margin granite. On the ANK vs. ACNK and tectonic discrimination diagrams, parental magma type of the granites corresponds to I-type, VAG and syn-collision granite. Interpretations of the chemical characteristics of the granitic rocks favor their emplacement in a compressional tectonic regime at continental margin during the subduction of proto-Pacific plate.

• Journal of the Mineralogical Society of Korea
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• v.30 no.1
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• pp.21-29
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• 2017

Surface soils on Barton Peninsula, King George Island, West Antarctica were investigated to acquire the mineralogical and geochemical data of soil in Antarctica. Multiline of techniques for example, X-ray diffraction (XRD), transmission electron microscopy (TEM)-electron energy loss spectroscopy (EELS), and wet chemistry analysis were performed to measure the composition of clay minerals, Fe-oxidation states, cation exchange capacity, and total cation concentration. Various minerals in sediments such as smectite, illite, chlorite, kaolinite, quartz and plagioclase were identified by XRD. Fe-oxidation states of bulk soils showed 20-40% of Fe(II) which would be ascribed to the reduction of Fe in clays as well as Fe-bearing minerals. Moreover, redox states of Fe in smectite structure was a ~57% of Fe(III) consistent to the values for the bulk soils. The cation exchange capacity of bulk soils ranged from 100 to 300 meq/kg and differences were not significantly measured for the sampling locations. Total cations (Mg, K, Na, Al, Fe) of bulk soils varies, contrast to the heavy metals (Co, Ni, Cu, Zn, Mn). These results suggested that composition of bed rocks influenced the distribution of elements in soil environments and soils containing clay compositions may went through the bio/geochemical alteration.

• Analytical Science and Technology
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• v.16 no.2
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• pp.143-151
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• 2003

In the present study, we made measurements of PM-bound metal concentrations from seven different urbanized locations in Seoul for the period covering March 2001 through May 2002. The measurement data were analyzed to explore the possible influences of spatial factors on metal distribution characteristics. To check for the importance of such aspects on metal distribution characteristics, the measured data were compared between different metals and between different sites by several criteria including (1) coefficient of variation (CV) values; (2) temporal variability; and (3) the abundance of strongly correlated pairs. The overall results of our study indicate strong diversity in the distribution characteristics of different metals. It is found that some metals (like Fe, Mn, and Pb) tend to exhibit strong compatibility among different study sites. However, no such compatibility appears to exist for certain metals like Cu. To account for the importance of spatial factors, complex relationships between source/sink processes and geochemical characteristics of a given metallic component may have to be examined in a systematic manner.