• Economic and Environmental Geology
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• v.23 no.2
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• pp.245-259
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• 1990

Petrochemical analyses of granitic rocks including trace element, REE and oxygen isotope were carried out to understand petrogenesis of plutonic rocks from the Chungju, Wolaksan and Jecheon granite batholiths, which might be related with tungsten-base metal-fluorite mineralization in the Hwanggangri metallogenic province. Different geochemical characteristics such as major and trace elements were found between Jurassic Daebo granitic rocks (Chungju, Jecheon, Wonju, and Boeun granitic rocks) and Cretaceous Bulgugsa granitic rocks (Wolaksan, Muamsa and Sokrisan granitic rocks). Cretaceous granitoids are characterized by high $SiO_2$and $K_2O$ contents and low $TiO_2$, $Al_2O_3$, MgO and CaO contents. They also have relatively high contents of trace elements(Zn, V, Co, Cr, Sr, and Ba) in comparison with the Jurassic granitoids. (Eu)/($Eu^*$) and $(La/Lu)_{CN}$ ratios of Jurassic plutons vary from 0.78 to 1.13 and from 26.02 to 30.5, respectively, while the ratios of Cretaceous ones range from 0.22 to 0.28 and from 4.42 to 14.2, respectively. The REE patterns of the Cretaceous and Jurassic granitic rocks have quite different Eu anomalies: large negative Eu anomaly in the former, and mild or absent Eu anomaly in the latter. The large Eu negative of Cretaceous granitic rocks are interpreted as a differentiated product of fractional crystallization of granitic magma deduced by Rayleigh fractionation model(Tsusue et al., 1987). Oxygen isotopic compositions of quartz for Daebo and Bulgugsa granitic rocks range from 9.98 to 10.51‰ and from 8.26 to 9.56‰, respectively. The Daebo granitic rocks enriched in $^{18}0$ suggest that the magma be undergone different partial melting processes from the Bulgugsa ones. Of the Bulgugsa granitoids, Wolaksan and Sokrisan mass have different contents of trace elements and ${\delta}\;^{18}0$ values of the silicate minerals, which indicate that they are not from the identical source of magma. Many mineral deposits are distributed in and/or near the Wolaksan and Muamsa granitic rocks, but a few mineral deposits are found in and near the Chungju and Jecheon granite batholiths. It might be depend on geochemisty of the related igneous rocks which have low contents of Ba, Sr, Co, V, Cr, Ni, Zn and high contents of Nb and Y, and on lithology of country rocks such as cabonate and noncarbonate rocks.

• Economic and Environmental Geology
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• v.28 no.6
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• pp.623-633
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• 1995

The Beonam deposits which is located in south-western part of Sobaeksan massif are emplaced along $N20{\sim}30^{\circ}E$ trending fissures in Precambrian Sobaeksan gneiss complex. Surrounding granites are inferred to be differentiated and formed from calc-alkaline magma which was generated from remelting or partial melting of the crustral material having igneous composition. The Sr isotope data of ore minerals showing significantly low initial Sr value relative to those of surrounding granite batholiths suggest that the ore-bearing fluid formed the Beonam Au-Ag mine are isotopically distinct from those of the wall rocks, and it indicates that there is no evidence of genetic relationship between ore-bearing fluids and surrounding granites, although further study should be needed. The results of paragenetic studies suggest three stages of hydrothermal mineralization; stage I: base-metal sulfides stage, stage II: late base-metal sulfides, electrum and silver-bearing sulfosalts stage, stage III: minor silverbearing minerals, barren quartz and carbonates stage. The temperature, salinity and pressure of the Beonam deposits estimated from mineral assemblage, chemical composition, fluid inclusion and sulfur isotope geothermometry are as follows; stage I: $200{\sim}315^{\circ}C$, 3.5~6.5 NaCl eq. wt%, 0.28~0.61 Kbar, stage II: $150{\sim}235^{\circ}C$, 4.5~7.4 NaCl eq. wt%, 0.11~0.15 Kbar. The estimated oxygen and sulfur fugacity during first stage mineralization, based on phase relation of associated minerals, range from $10^{35.1}{\sim}10^{-39.7}$ atm. and $10^{-11.0}{\sim}10^{-13.4}$ atm., respectively. All these evidences suggest that the Beonam deposits are polymetallic meso-epithermal ore deposits.

• The Journal of Engineering Geology
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• v.13 no.1
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• pp.107-127
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• 2003

After detailed geological mapping, structural and fracture-density data were collected and analyzed in the vicinity of Cheonseong and Jeongjok Mts., Gyeongsangnam-do. A extensive dextral strike-slip fault (Beopgi Fault) Parallel to Yangsan and Dongrae Faults, a dextral-transtensional-NW fault, and a few intermittent faults have been found in the study area. Based on strike and frequency, fracture system has been divided into three sets such as NNE-trending J1 ($NS-40^{\circ}E$), WNW-trending J2 ($N50^{\circ}-80^{\circ}W$), and ENE-trending J3 ($N60^{\circ}-90^{\circ}E$). According to analysis of fracture density, it is revealed as follows: (a) Jl is the combination of Y-, P-, and R-shear fractures due to the dextral strike-slip of the Beopgi Fault. (b) J2 is the preexisted fracture zone conducting the intrusion of granite. Two tensional fractures dipping to NNE and SSW respectively have been induced by intrusion of granite and followed crustal uplift. (c) J3 is the tensional fracture developed between Yangsan and Dongrae Faults having NNE trend and dextral strike-slip sense. This study aims to reduce environmental impact and insure stability of underground facilities and tunnels.

• The Journal of Engineering Geology
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• v.13 no.1
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• pp.1-16
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• 2003

Geochemical characteristics of groundwater in the different kinds of various lithology such as Haman formation, Panyaweol formation, Jusan andesitic formation and Palgongsan granite is distinguished by mineralogical and chemical compositions. The Concentration of the majority of solutes in groundwaters of Haman and Panyaweol formation is higher than in that of andesite and granite. Higher concentration of $HCO_3^{-}{\;}and{\;}SO_4^{2-}$ anions in the groundwater is peculiar. High concentrations of $Ca^{2+},{\;}Mg^{2+},{\;}HCO_3^{-}$ in the groundwaters of the sedimentary rocks result mainly from reaction of $CO^{2-}$ charged water with calcite and weathered feldspars. With the Piper diagram, the groundwaters of Haman formations are mainly plotted in $CaSO_4-CaCl_2$ type, whereas those of Panyaweol formations are plotted in the bothside of $Ca(HCO_3)_2{\;}and{\;}CaSO_4-CaCl_2$ type. Thses two different types of $Ca(HCO_3)_2{\;}and{\;}CaSO_4-CaCl_2$ groundwater were originated from dissolution of calcite($Ca(HCO_3)_2)$ and the oxidation of pyrite($CaSO_4-CaCl_2$), respectively. And it also is influenced by anthropogenic contamination. Three factors were extracted from the factor analysis for chemical data. Factor 1, controlled by $SO_4^{2-},{\;}Na^{+},{\;}Ca^{2+}$ and Fe, explains the dissolution of calcite, plagioclase and oxidation of pyrite. Factor 2, controlled by $HCO_3^{-}{\;}and{\;}Mg^{2+}$, mainly explains the dissolution of Mg-carbonates and dolomitization. Factor 3, controlled by $Cl^{-},{\;}K^{+}{\;}and{\;}NO_3^{-}$, is subject to the influence of artificial pollution including industrial waste water disposal. In this study area, some industrial complex which is close to Keumho river show the higher score of factor 3.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.5 no.4
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• pp.273-281
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• 2007

Hyperalkaline groundwater formed by groundwater-cement components and its reaction with bedrock in a nuclear waste repository were simulated by geochemical modeling. The result of groundwater-cement components reaction showed that the pH of water was 13.3 and the precipitated minerals were Brucite, Katoite, Calcium Silicate Hydrate(CSH1.1), Ettringite, Hematite, and Portlandite. The result of interaction between such minerals and groundwater sampled in Gyeongju area also showed that the pH of groundwater reached 12.4. Interaction between such hyperalkaline groundwater and granite was simulated by kinetic model during $10^3$ years. This result showed that the final pH of groundwater reached 11.2 and the variation of pH was controlled by dissolution/precipitation of silicate and CSH minerals. Groundwater quality was also determined by dissolution/precipitation of silicate, CSH, oxide minerals. Our results show that geochemical modeling of long-term hyperalkaline groundwater and rock interaction can contribute to the safety assessment of engineered barrier by predicting geochemical condition in repository site.

• Journal of the Korean Geotechnical Society
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• v.18 no.4
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• pp.319-327
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• 2002

In this research, problems of recent design methods and their improvement for SIP(Soil-Cement Injected precast Pile) in domestic areas were studied by using the properties of load-settlement curves and bearing capacity from field loading tests. Elastic and plastic settlement for total settlement in each loading step of loading tests conducted in domestic areas has been shown to have a tendency. From this tendency and bearing capacity determined by loading tests, it could be ascertained that empirical chart could be an assistant tool in SIP design. It was shown that SIP design using N-value in domestic area with soil condition of granitic type resulted in very conservative hearing capacity. On the other hands, in soil with unfitted geological conditions, the design could be insecure. Also, we could ascertain that Meyerhof's bearing capacity using modified N-value on the tip part of pile was more applicable than recent design method where tip bearing capacity was 20NA$_p$ N-value limited to 50. These results showed that modified design method could be more economic than those in the past because it used pile's bearing capacity unto tolerable load of pile material.

• The Journal of Engineering Geology
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• v.15 no.2 s.42
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• pp.185-199
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• 2005

Properties of sliding materials are dependent on the lithology because debris is the product of rock weathering processes. In order to characterize transportation behavior of debris dependent of debris types, this study selected 26 debris flows over three areas composed with different rock weathering types and topographic conditions. Analyses of lithology, weathering, and topographic characteristics were performed by detailed field survey. Based on the field survey data, transportation behavior of debris was studied at the aspect of the relationship of grain size and volume of debris as well as topographic conditions. According to the study results, change of slope angle is very influential factor on runout distance of debris among the topographic factors. Because the sliding velocity and the energy of debris are frequently changed and more irregular on an undulating slope, the unout distance of debris is larger than that of an uniformly dipping slope. Runout distance of debris is also influenced by volume and grain size of debris. Volume of debris in the gabbro is four or five times larger than that of the granite area because it is controlled by the lithology. Considered with grain size distribution, runout distance of debris is longer in the gabbro area which is composed with irregular grain size bearing large corestones than that in the medium grained granite area.

• Journal of the Korean GEO-environmental Society
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• v.3 no.2
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• pp.35-47
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• 2002

Soil and rock were yielded during construction of subway in Taegu. Produced rock is a kind of a sedimentary rock with low strength and low durability of shrinkage. So it is difficult using for resources engineering. But in our country, it is very important to use material resources due to lack of natural resources. In this study, after cracking sedimentary rock like black shale and red shale, they are compared with granite which usually used road constriction field to investigate property of use for road construction. Consequently, the engineering character of origin rock is satisfactory, but the soundness test, black shale and red shale are less than KS 12.9%, 37.5% respectively. The result of concrete freezing-thawing test shows that the strength among three materials is not a wide difference but red shale has relatively low strength. The result of asphalt freezing-thawing test with 50 cycles indicates that the stability of red shale in lower than KS 484~561kg on base course, 336~375kg on surface course respectively. A further research should be needed for propriety to the material of shale.

• The Journal of the Petrological Society of Korea
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• v.6 no.3
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• pp.166-184
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• 1997

The Wondong caldea is a deeply eroded structure that offers spectacular exposures through the core and margins of a resurgent caldera. The Wondong Tuff and the postcollapse intrusions range from medium-silica rhyolite to rhyodacite in composition and the postcollapse lava and tuff, preresurgent and resurgent intrusions also range from medium-silica rhyolite to an-desite, which jump to gap dacite composition. The continuous compositional zonations generally define a large stratified magma system in the postcollapse and resurgent magma chamber. Isotopic and trace element evidence suggest that the compositional zonations might have resulted from the differentiations from crystal fractionations of a parental andesitic magma, accompanying a little contamination from the crustal assimilations near the chamber roof and wall. But chemically and isotopically distinct late intusions might have resulted from emplacement of any different magma batch.

• Journal of Radiation Protection and Research
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• v.38 no.3
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• pp.138-142
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• 2013

This study was conducted to measure the uranium concentrations in urine of some members of the general public in Busan and Daejeon and to assess the annual committed effective doses from uranium analysis of daily excretion. As a result, the ranges of total uranium concentrations in the urine for the residents in Busan and Daejeon were found to be 0.556 - 1.53 $mBq\;L^{-1}$ and 2.18 - 4.55 $mBq\;L^{-1}$, respectively. It was noted that the uranium concentrations for the residents in Daejeon were observed to be higher than those for the residents in Busan. This result assumes that the uranium concentrations in the urines for the residents in Daejeon are probably related to the high uranium concentrations contained in the drinking water of Daejeon city. The bedrock of Daejeon, known as granitic rocks formed in the Jurassic period of the Mesozoic Era, contains high uranium contents. Also, results showed no significant correlation with age or sex. The ranges of annual committed effective doses from ingestion of uranium for the residents in Busan and Daejeon were calculated to be 0.472-1.41 ${\mu}Sv$ and 1.99-4.15 ${\mu}Sv$, respectively.