• Economic and Environmental Geology
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• v.41 no.6
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• pp.695-708
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• 2008

In order to evaluate the geochemical behaviors of elements with waste rocks in the abandoned Jangpoong Cu mine area, total concentration analysis and leaching experiments were performed. The content of elements within waste rocks compared with background values decreased in order of As>>Cu>Pb>Cd>Co. Leaching experiments were carried out at various extraction environments, considering the acid rain ($0.00001{\sim}0.001N\;HNO_3$) and the acid mine drainage ($0.001{\sim}0.1N$ HNO3). After 24 hours of reaction with different acidic solution, the leaching characteristics of waste rocks were classified into three types according to final pH of leaching solution. Type I refers to the case that the final pH of leaching solution was lower than that of the reaction solution due to the dissolution of acidic minerals from rocks, while type 2 and 3 refer to the case that the final pH maintained higher than that of the reaction solution. Theses types include in acid buffering minerals such as clay minerals and carbonate minerals. The leaching characteristics of the elements after the reaction could be categorized into As-Co-Fe, Cu-Mn-Cd-Zn, and Pb. As-Co-Fe started to get leached under 2.5 of pH regardless of changes in the final pH, and Cu-Mn-Cd-Zn showed different initial leaching pH according to the types of final pH changes. Based on the pH value where leaching started regardless of leaching concentration, the relative mobility of each element was in the order of Mn Zn>Cd>Cu>>Fe Co>As>Pb. Thus, more higher mobility elements(Zn, Mn and Cu) were leached by reacting with acid rain water. Acid mine drainage may result in distributions of elements having relatively less mobility(As, Fe, Co and Pb).

• Economic and Environmental Geology
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• v.55 no.3
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• pp.241-259
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• 2022

In general, the REE were produced by mining conventional deposits, such as the carbonatite or the clay-hosted REE deposits. However, because of the recent demand increase for REE in modern industries, unconventional REE deposits emerged as a necessary research topic. Among the unconventional REE recovery methods, the REE-bearing coal deposits are recently receiving attentions. R-types generally have detrital originations from the bauxite deposits, and show LREE enriched REE patterns. Tuffaceous-types are formed by syngenetic volcanic activities and following input of volcanic ash into the basin. This type shows specific occurrence of the detrital volcanic ash-driven minerals and the authigenic phosphorous minerals focused at narrow horizon between coal seams and tonstein layers. REE patterns of tuffaceous-types show flat shape in general. Hydrothermal-types can be formed by epigenetic inflow of REE originated from granitic intrusions. Occurrence of the authigenic halogen-bearing phosphorous minerals and the water-bearing minerals are the specific characteristics of this type. They generally show HREE enriched REE patterns. Each type of REE-bearing coal deposits may occur by independent genesis, but most of REE-bearing coal deposits with high REE concentrations have multiple genesis. For the case of the US, the rare earth oxides (REO) with high purity has been produced from REE-bearing coals and their byproducts in pilot plants from 2018. Their goal is to supply about 7% of national REE demand. For the coal deposits in Korea, lignite layers found in Gyungju-Yeongil coal fields shows coexistence of tuff layers and coal seams. They are also based in Tertiary basins, and low affection from compaction and coalification might resulted into high-REE tuffaceous-type coal deposits. Thus, detailed geologic researches and explorations for domestic coal deposits are required.

• Journal of Life Science
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• v.19 no.10
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• pp.1410-1416
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• 2009

The present study aims to examine the effect of turbid water on fishes in streams which branch into a turbid water area (Yeongyang-gun) and a non-turbid water area (Cheongsong-gun), and finally flow into the Imha reservoir. In a comparison of water quality, the chemical status of the water showed higher pH, DO and SS in the turbid water area than in the non-turbid water area. Also, high density of clay minerals such as vermiculite (V) and illite (I), which is from clay mineral leakage during rainfall, was detected in turbid water, resulting in an increase of turbidity. Fishes inhabiting the turbid water showed irregular spaces in gill lamella, cell separation, edema, and clubbing in epithelial tissues. Also, the gill surface showed roughness and plenty of muddy debris substances inside the gills. The Bowman's space was expanded because of contraction of the glomerulus in the Bowman's space of the kidney tissues. Antioxidant enzymes such as SOD, CAT, GPX, and GST showed higher activities in the specific tissues, muscles and kidney, of fishes living in turbid water than in the non-turbid area. We suggested that; first, the antioxidant activities were increased due to removal of harmful radicals generated in fish bodies in the turbid water area, second, long-time exposure of these histological changes in the tissues might have induced secondary lesion accompanying the inaccurate physiological constancy of fishes.

• Journal of the Mineralogical Society of Korea
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• v.18 no.2
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• pp.135-144
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• 2005

In the high-Ca limestone zone of the Pungchon Formation of the Lower Chosun Supergroup, cryptocrystalline alterations with reddish brown color occur as fissure-fillings or coatings, which was originated from the upper formation, i. e., the Hwajeol Formation. The precipitates result in degradation and contamination of the high-Ca limestone ore in grade and quality, showing characteristic occurrence and mineral composition typical of suggesting a supergene origin. Chalcedonic quartz, kaolinite, illite, goethite and hematite are constituting a characteristic authigenic mineral assemblage and, in places, smectite is less commonly included in the weathering product. In addition to these authigenic phases, some detrital minerals such as mica and orthoclase constituting relatively coarser grains are also rarely present in the supergene alterations. A rather complex clay facies consisting of kaolinite, illite and smectite in the alterations seems to correspond to the typical clay composition of the reported residual pedogenic soils by limestone weathering. The cryptocrystalline weathering product is partly altered to stilbite, a characteristic hydrothermal zeolite, in places, by the hydrothermal contact of late stage. The time of formation and infiltration of the supergene alterations seems to correspond to the stage just after the epithermal alteration of the Pungchon Limestone, i. e., an early Jurassic age. The supergene alteration, which may imply the stage of uplifting, weathering and erosion of the Chosun Supergroup, appears to have undergone at an oxygen-rich environment in descending water of meteoric origin by means of a chemical leaching and diffusion.

• Journal of the Mineralogical Society of Korea
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• v.24 no.3
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• pp.165-178
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• 2011

The potential of petroleum generation was investigated by clay mineralogical changes of illite-smectite on the sedimentary basins: Tertiary Pohang basin and Cretaceouls Gyeongsang basin on land, and offshore basins east and west of Korea. Only disordered illite-smectite mixed layer minerals occur in the Pohang sediment, where petroleum generation cannot be expected due to low temperatures below $100^{\circ}C$. By contrast, the Gyeongsang basin is characterized by the occurrence of illite and high temperatures above $200^{\circ}C$ which are obtained by illite crystallinity. The high temperatures indicate that the Gyeongsang sediment ha, already passed through the oil generation stage. The change of disordered illite-smectite to R-l ordered illite-smectite is shown in the sediment of the East Sea continental shelf area at a depth of 2,500 m. Therefore, the oil generation can be expected in the sediments below the depth of 2,500 m. The sequential change of disordered illite-smectie to R=3 ordered illite-smectite through R=l ordered illite-smectite occurs in the sediments of West Sea continental shelf area with burial depth which shows the favorable condition for oil and gas generation. The temperatures of sediments measured by illite-smectite indicate that hydrocarbon potential is very low in the onland basins but high in the continental shelf areas.

• Korean Journal of Mineralogy and Petrology
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• v.35 no.1
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• pp.51-64
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• 2022

For effective preservation of the rocks, which bearing plant fossils at Gumkwangdong Formation, Pohang, the properties of rock and treatment of chemicals were examined in an artificial weathering test. The rocks are diatomaceous siliceous mudstone, which contain a small amount of smectite and has developed laminated layers. The rocks react with water, the d₀₀₁ spacing of smectite was increased. On the one hand, the physical properties of the rock samples, such as surface hardness, improved after the application of ethyl silicate-based stone strengthener. On the other hand, the spacing of interlayer of swelling clay minerals decreased and spacing of laminae layer increased. When the ethyl silicate-based stone strengthener was applied after pretreatment with a swelling inhibitor, interlayer and spacing of laminae changes were similar to those when only the stone strengthener was treated. The effect of the swelling inhibitor was almost negligible. When the rocks that have been conserved with chemicals react with water, spacing of laminae has widened much, whereas when the rocks was in contact with moisture only, there was little change. In addition, if it is placed in the outdoor after conservation treatment, although it occurs slightly slower than the untreated rock, the separation of the lamination layer and the pulverization of the rock occur within a very short time. Consolidation is required to improve the physical properties of fossil rock, but when exposed to rain and undergoing freeze-thaw process, the effect is lost very quickly. Therefore, regardless of the chemical treatment, it is a priority to prevent direct rainfall contact with the rock.

• Journal of the Korean Geotechnical Society
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• v.25 no.6
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• pp.17-29
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• 2009

There has been an increase in the investigation of deep sea sediments with a consequent increase in the amount of energy required to undertake these investigations. The geotechnical characteristics of Ulleung Basin sediment are explored by using depressurized specimens following methane production tests carried out on pressured core samples obtained at 2,100 m water depth and 110 m below sea floor. Geotechnical index tests, X-ray diffraction, and scanning electron microscope are conducted to identify the geotechnical index parameters, clay mineralogy, chemical composition, and microstructure of the sediments. Compressibility, and elastic and electromagnetic wave parameters are investigated for two samples by using a multi sensing instrumented oedometer cell. The strength chatracteristics are obtained by the direct shear tests. The dominant clay minerals are mostly kaolinite, illite, chlorite, and calcite. The SEM shows a well-developed flocculated structure of the microfossil. Void ratio, electrical resistivity, real permittivity, conductivity, and shear wave velocity show bi-linear behavior with the effective vertical stress: as the vertical effective stress increases. The friction angle obtained by the direct shear test is about $21^{\circ}$, which is similar to the value observed in the Ulleung Basin sediments. This study shows that the understanding of the behavior acting on the diatomaceous marine sediment is important because it often maintains the useful energy resources such as gas hydrate and so will be the new engineering field in the next generation.

• Economic and Environmental Geology
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• v.56 no.5
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• pp.515-532
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• 2023

Bentonite, predominantly consists of expandable clay minerals, is considered to be the suitable buffering material in high-level radioactive waste disposal repository due to its large swelling property and low permeability. Additionally, the bentonite has large cation exchange capacity and specific surface area, and thus, it effectively retards the transport of leaked radionuclides to surrounding environments. This study aims to review the thermodynamic sorption models for four radionuclides (U, Am, Se, and Eu) and eight bentonites. Then, the thermodynamic sorption models and optimized sorption parameters were precisely analyzed by considering the experimental conditions in previous study. Here, the optimized sorption parameters showed that thermodynamic sorption models were related to experimental conditions such as types and concentrations of radionuclides, ionic strength, major competing cation, temperature, solid-to-liquid ratio, carbonate species, and mineralogical properties of bentonite. These results implied that the thermodynamic sorption models suggested by the optimization at specific experimental conditions had large uncertainty for application to various environmental conditions.

• Korean Journal of Soil Science and Fertilizer
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• v.19 no.2
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• pp.99-105
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• 1986

This study was carried out to compare the soil profile development indices of Sinjeong series according to the distribution areas in Yeongnam district. The results obtained were as follows; 1. The soils studied were belong to fine loamy family of hilly residual soils derived from conglomerate. These soils were well drained and dominantly had 30-60% slopes, and used for forest. 2. The surfaces were typified by brownish red (5YR) or brownish yellow (10YR) loam, subsoils were clay loam of reddish brown (5YR) or reddish yellow (7.5YR) and the substrata were in dark reddish brown (5YR) or pink (7.5YR) sandy loam. 3. The indices of horizon development of the soils studied were from 0.18 to 0.38 and the index in illuvial horizons with clay films were over 0.36, that were higher than the others. The profile development indices were similar to each other ranging from 30.18 to 35.93. 4. Positive correlations were observed among horizon development indices and normalized values of structure, texture and consistences, but the relationship between profile development indices and consistences were not the same. 5. The amount of clay minerals formed in the soil horizons per 100g of parent materials were 1.1-1.6g and the rates of the clay leached were around 4.4-5.9%. 6. The sphericity and roundness of the gravels contained in the soils studied were 0.741 and 0.715, respectively. These similarity of "well rounded" gravels certify that the parent rocks were formed under similar environments.

• Korean Journal of Soil Science and Fertilizer
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• v.18 no.2
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• pp.177-188
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• 1985

To clarify the characteristics and genesis of clayey terrace soils in Yeongnam area, macro-morphological features and soil profile development indexes were investigated with the sequential soils in Yeongcheon (inland region) and in Yeongil (coastal region). The results are summarized as follows; 1. According to the physiogaphy and landuse, the terrace soils were discernible to well drained yellowish red (5 YR) profile of higher terrace (Bancheon series), moderately well drained reddish yellow (7.5 YR) profile of middle terraces (Upyeong and Hwadong series), and lower terraces (Deogpyeong and Geugrag series) which were moderately well to imperfectly drained by paddy-fication. 2. The roundness and sphericity of the gravels contained in the terrace deposits were ranged around 0.543-0.546 and 0.723-0.722, respectively. The rounded to well rounded gravels were resemble to typical alluvial origins. 3. The amount of clay minerals formed in the soil horizons per 100g of parent materials were 50.8-30.7g while the rates of the clay leached were 30.1-7.4%, and the higher terrace had the more leaching rates. 4. The index of profile development of the terrace soils ranged from 37.95 to 22.01 and the index were positively correlated with relative elevations of the soils. The rates of clay leaching were positively correlated with the ratios of clay in the illuvial horizons to elluvial horizons. 5. A similarity was observed among cumulative grain size curves of the terrace soils, but the patterns of recalculated silt free cumulative grain size curve of terrace deposits in Upyeong soils in Yeongil area were abruptly different from down layer that suggest the soil to have bisequum profile.