• Journal of the Mineralogical Society of Korea
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• v.31 no.4
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• pp.257-266
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• 2018

East China Sea (ECS) is known to be supplied with large amounts of sediments form Huanghe, Changjiang and various rivers in Korea. Many studies have been conducted to identify the effects of rivers and deposition process of ECS, but no consensus has been reached. In this study, clay minerals, rare earth elements (REEs) and grain size were analyzed to study the provenance and sedimentation environment of core 99MAP-P63 in ECS. Clay mineral contents of 99MAP-P63 are abundant in order of illite, chlorite, kaolinite, and smectite. The provenance of 99MAP-P63 sediments using clay minerals is interpreted as the Changjiang regardless of depth. As a result of REEs analysis, 99MAP-P63 sediments are very similar to Chinese rivers sediments. Therefore, the provenance of 99MAP-P63 is Changjiang, and the influence of Korean river seems to be insignificant. 99MAP-P63 sediments are generally classified as sandy silt, but the top of the core is divided into sand with a sand contents of 85 %. Compared with surrounding cores, sandy silt sediments arecorresponded to the low stand stage when sea-level was low, and the sediments were thought to have been supplied directly through the paleo-Changjiang. Sandy sediments in uppermost of core are corresponded to transgressive stage. Although distance from estuary was increased due to sea-level rise, it was possible to supply coarse sediments due to high bottom stress, and the paleo-Changjiang sediments deposited in study area were re-deposited.

• 한국해양학회지
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• v.26 no.4
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• pp.332-339
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• 1991

The sedimentation pattern in Namhaepo Bay, a macrotidal coastal embayment of western Korea, was investigated by means of analysing high-resolution seismic profiles, sediment samples, and tidal currents. Recent sediments up to 20 m which overlie the irregular surface of the acoustic basement. The sediments consist mainly of sandy silt and silt; the mean grain size of these sediments ranges from 4 to 5.5 phi, showing a shoreward-fining distribution pattern. This distribution pattern agrees are largely reversed during ebb, with a maximum velocity of 39 cm/sec. The calculated shear velocity of the tidal currents at sea bed ranges from 0.5 to 3.3 cm/sec during flood and from 0.7 to 2.5 cm/sec during ebb. The mean values of these velocities exceed the critical shear velocity for the silt particles. The data suggest that the tidal currents play an important role in the transportation and deposition of sediments in the bay and the surface topography of the sea floor is largely deter-mined by tidal sedimentation.

• Korean Journal of Soil Science and Fertilizer
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• v.48 no.6
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• pp.582-587
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• 2015

This study was conducted to compare the plant growth and fruit quality of blueberries grown in different soil textures of Korea, in order to utilize the results for stable production and soil improvement. Rabbiteye blueberry cultivars 'Tifblue' and 'Baldwin' were planted and grown for three years from 2013 in wagner pot (1 $2000a^{-1}$) in a greenhouse of Namhae Sub-station, Institute of Horticultural and Herbal Science. The plants were grown in four soil textures, sand, sandy loam, loam and silt loam, and nutrient uptake and growth characteristics of plants were investigated. Leaf nitrogen and phosphorus contents of two cultivars grown in different soil textures ranged between 8.6 to $10.5gkg^{-1}$, which was lower than appropriate level for rabbiteye blueberry. However, the contents of potassium, calcium and magnesium in leaves were appropriate levels as $2.29{\sim}3.62gkg^{-1}$, $4.46{\sim}5.46gkg^{-1}$ and $1.45{\sim}2.12gkg^{-1}$, respectively. Nitrogen and phosphate contents in leaves were higher in the two cultivars grown in silt loam soil. There was no significant difference in plant volume and root dry weight among four soil textures in two cultivars. However, dry weight of leaves and branches were highest in loam soil. Fruit production was highest in loam and silt loam soil in two cultivars, showing negative correlation with the amount of sand in soil. However, sugar and acidity showed no correlation with sand content in soil. These results show the limit to the blueberry growth in soil that has no nutrient holding capacity; however, most of Korean soils that have good nutrient holding capacity can produce competitive fruits if the drainage is improved.

• Korean Journal of Soil Science and Fertilizer
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• v.38 no.5
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• pp.231-237
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• 2005

Gypsum treated to fine sandy loam increased the fornation of >2 mm aggregates in $1,550kg\;CaSO_4{\cdot}2H_2O\;10a^{-1}$ (Kbfg1) and $3,100kg\;CaSO_4{\cdot}2H_2O\;10a^{-1}$ (Kbfg2) to compare with control, Kc, at 60DAT, and bigger aggregates in general at 90DAT. The higher treatment of gypsum level, the <0.1 mm aggregates were less decreased as in Kbfg1, Kbfg2, and $6,200kg\;CaSO_4{\cdot}2H_2O\;10a^{-1}$ (Kbfg3) and aggregates of 0.25->2 mm were increased with increasing level of gypsum with more effective in Kbfg2 and Kbfg3 at 120DAT. Gypsum treated to silt loam increased aggregates of 2.0-1.0 and 1.0-0.5 mm in $3,100kg\;CaSO_4{\cdot}2H_2O\;10a^{-1}$ (Mbfg2) to compare with control (Mc), at 60DAT. Degrees of aggregation from 0.5-0.25 mm to >2 mm aggregates at 90DAT were distinctly higher. The higher treatment of gypsum level accelerated more aggregation of silt loam soil, and aggregates of 0.5-0.25 mm was most increased in Mbfg2 at 120DAT. Popped rice hulls treated to fine sandy loam increased aggregates of 2.0-1.0 mm in plots of $1,000kg\;10a^{-1}$ (Kbfhl) only to compare with control (Kc), at 60DAT, and aggregates of >2 mm and 2.0-1.0 mm Kbfh1 at 90DAT. At 120DAT, aggregation by popped rice hulls was most effective in Kbfbl pot. Popped rice hulls treated to silt loam increased in aggregates of >2 mm and 2.0-1.0 mm in $2000kg\;10a^{-1}$, Mbfb2 to compare with control, Mc, at 60DAT. Degrees of aggregation by popped rice hulls at 90DAT were higher in $1,000kg\;10a^{-1}$, Mbfh1, and Mbfh2, and at 120DAT was in $3,000kg\;10a^{-1}$, Mbfb3. Zeolite treatment with popped rice hulls, $1,500kg\;10a^{-1}$, increased in >2.0 mm aggregates in $1,000kg\;10a^{-1}$, Kbfbz1, $2,000kg\;10a^{-1}$, Kbfbz2, $3,000kg\;10a^{-1}$, Kbfhz3, and Mbfbz1, $1,000kg\;10a^{-1}$, Mbfbz2, $2,000kg\;10a^{-1}$, and $3,000kg\;10a^{-1}$, Mbthz3, to compare with control (Kc and Mc), at 60DAT. irrespective of soil texture. At 90DAT, >2.0-0.5 mm aggregates increased in Kbfhz1 of fine sandy loam. aggregates of >0.25 mm in $200kg\;10a^{-1}$ (Mbfbz1), $400kg\;10a^{-1}$ (Mbfhz2), $800kg\;10a^{-1}$ (Mbfhz3) of silt loam increased with the level of zeolite treatment. At 120DAT, the effect of zeolite treated to both soils showed the decrease of <0.1 mm aggregates. As the result, soil amendments for soil aggregation was more effective in the order of popped rice hulls+Zeolite > gypsum > popped rice hulls in fine sandy loam, and in the order of gypsum > popped rice huUs+zeolite > popped rice hulls in silt loam, respectively.

• Korean Journal of Medicinal Crop Science
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• v.14 no.3
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• pp.143-147
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• 2006

This study was carried to investigate the effect of soil texture on the growth and the contents of quercetin-glycoside and lignans, and to improve the qualities of Saururus chinensis Baill. Soil texture resulted no significant effects on the number of nodes, the number of leaves, the number of branches and dry matter ratio. However, the shoot dry weight was higher in sandy loam, loam, silt loam and sand soil in that order. Although the weight of rhizomes of below 5 mm in diameter was not significantly different among soil textures, the weight of rhizomes between 5.1 and 10.9 mm and the weight of rhizomes of above 11 mm in diameter ranged $437{\sim}465\;g$ and was larger in clay loam than in other soil textures. No significance difference was showed in rhizome dry ratio ranging from 19.1 to 20.8%. The amount of quercetin-glycoside in leaves was higher in loam and sandy loam and ranged from 219.3 to 222.4 mg/100 g of quercetin-glycoside quercitrin, rutin, isoquercitrin and hyperin were higher in that order. On the other hand, quercetin-glycoside contents in stem were 14.8 mg/100 g and 12.4 mg/100 g in sandy and sandy loam, respectively, and were higher than in other soil textures of quercetin-glycoside constituents, the content of rutin was the highest. The content of lignans was increased in clay loam, loam, sandy loam, and sandy in that order of lignans, the manassatin B was the highest.

• Economic and Environmental Geology
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• v.47 no.5
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• pp.479-488
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• 2014

Naturally occurring asbestos (NOA) from disturbance of rocks and soils has been overlooked as a source of exposure that could potentially have a detrimental impact on human health. But, few researches on mineralogical characteristics of NOA occurred in soils have been reported in Korea. Therefore, the objective of this study was to investigate the mineralogical characteristics of NOA occurred in soils at Daero-ri area, Seosan, Chungnam Province, Korea. Sedimentation method was used for particle size separation of the asbestos-containing soils. XRD and PLM analyses were used to characterize mineralogical characteristics and mineral assemblages in soils. SEM-EDS and TEM-EDS analyses were used to characterize mineral morphology and chemical composition. Particle size analyses of the asbestos-containing soils showed they were composed of 26-93% sand, 4-23% silt and 3-70% clay. Soil texture of the soils was mainly sand, sandy loam, sandy clay, and clay. PLM analyses of the soil showed that most of the soil contained asbestiform tremolite and actinolite. The average content of asbestos in the soil was 1.5 wt. %. Therefore, the soil can be classified into asbestos-contaminated soils based on U. S. Environmental Protection Agency classification (content of asbestos in contaminated soil > 1%). Morphologically different types of tremolite such as long fibrous, needle-like, fiber bundle, bladed and prismatic forms co-existed. Prismatic tremolite was dominant in sand fraction and asbestiform tremolite was dominant in silt fraction. This study indicates that the prismatic form of tremolite transform gradually into a fibrous form of tremolite due to soil weathering because tremolite asbestos was mainly existed in silt fraction rather than sand fraction.

• Journal of Soil and Groundwater Environment
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• v.17 no.4
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• pp.36-43
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• 2012

Various methods are used to remediate soil contaminated with heavy metals or petroleum. In recent years, harsh physical and chemical remediation methods are being used to increase remediation efficiency, however, such processes could affect soil properties and degrade the ecological functions of the soil. Effects of soil washing, thermal desorption, and land farming, which are the most frequently used remediation methods, on the physicochemical properties of remediated soil were investigated in this study. For soils smaller than 2 mm, the soil texture were changed from sandy clay loam to sandy loam because of the decrease in the clay content after soil washing, and from loamy sand to sandy loam because of the decrease in the sand content and increase in silt content during thermal desorption, however, the soil texture remained unchanged after land farming process. The water-holding capacity, organic matter content, and total nitrogen concentration of the tested soil decreased after soil washing. A change in soil color and an increase in the available phosphate concentration were observed after thermal desorption. Exchangeable cations, total nitrogen, and available phosphate concentration were found to decrease after land farming; these components were probably used by microorganisms during as well as after the land farming process because microbial processes remain active even after land farming. A study of these changes can provide information useful for the reuse of remediated soil. However, it is insufficient to assess only soil physicochemical properties from the viewpoint of the reuse of remediated soil. Potential risks and ecological functions of remediated soil should also be considered to realize sustainable soil use.

• Journal of The Geomorphological Association of Korea
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• v.26 no.1
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• pp.59-78
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• 2019

The physical and chemical characteristics of more than 5 m sandy deposits behind the beach in Sinji-do Island are investigated and its burial ages are estimated using Optically Stimulated Luminescence. By the estimated burial ages of the sandy deposits, this section is divided into four sub-units: Unit I (6.2 ka), Unit II (23.2 ka), Unit III (115.9 ka), and Unit IV (115.9 to 127.5 ka). It can be proposed that the Unit I of a coarse sand deposited during the Holocene Climatic Optimum. Unit II, supposed to be the aeolian sediments, formed during the Last Glacial Maximum (LGM). It can be supposed that the study area was not affected by the marine processes during the LGM, directly. Unit III is more consolidated deposits of coarse silt to fine sand and deposited during the Last Interglacial Period. Unit IV mainly consist of beach gravels with sandy matrix deposited during the Marine Isotope Stage 5e (MIS 5e), and thus indicates that the sea level of the southwest sea had risen 3 to 5 m above present sea level during the MIS 5e.

• Journal of the Korean earth science society
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• v.22 no.5
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• pp.377-387
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• 2001

In order to elucidate sedimentation processes and depositional environments in transitional area between continental shelf and coastal zone, sedimentologic study has been done with 84 surface sediments sampled in nearshore/offshore off the mid-western coast of the Korean Peninsula for 3 years (1996${\sim}$1999). The surface sediment can be classified into 4 facies (gravelly sand, sand, silty sand and sandy silt). Mean grain size, sorting, skewenss and kurtosis varies -0.39${\sim}7.82{\Phi}$, 0.36${\sim}4.68{\Phi}$, -0.38${\sim}$0.86, -1.56${\sim}$3.43, respectively. The textural parameters show a finer-grained and poorly-sorted trend shoreward, northward and southward from the central part of the study area. The positively-skewed distribution and relationship of each textural parameters indicate a tide-dominated depositional environment. According to C/M diagram, there are 3 different domains (mode A, B, C) of sediment transport mode. The northern part is characterized by bedload transport (mode A) and represents co-influence of wave and tide, whereas domain C in the southern part is controlled by uniform suspension transport (mode C), correlating with sandy-silt area. In the broad middle area, transport processes are complex (the mixture of bedload, graded suspension and uniform suspension; mode B). Hence, the subdivision depositional environments of this study area may be classified by 3 depositional environments dependent on the interplay of sediment supplies from river, relict sediments and hydrologic conditions. In results, the nearshore and offshore areas are thus characterized as a mixing zone between coastal terrigenous sediments and relict sediments in the continental shelf by complex processes (tide, wave and river flow). These sedimentation processes play an important role in producing distinct sedimentologic features in the transitional zone linking coastal and shelfal areas.

• Journal of the Korean Geotechnical Society
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• v.28 no.7
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• pp.31-40
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• 2012

In most design codes, soils are classified as either sandy or clayey soils, and appropriate design equations for each soil type are used to estimate their soil behaviour. However, sand-fine mixtures, which are typically referred to as intermediate soils, are somewhere at the middle of sandy or clayey soils, and therefore a unified interpretation of soil behaviour is necessary. In this paper, a series of cyclic shear tests were carried out for three different combinations of sand-fine mixtures with various fines content. Silica-sand mixture and fines (Iwakuni natural clay, Tottori silt, kaolinite) were mixed together with various mass ratios, while paying attention to the changes of void ratios expressed in terms of sand structure. The cyclic shear strengths of the mixtures below the threshold fines content were examined with the increasing fines contents. As a result, as the fines contents increased, their cyclic deviator stress ratios decreased for dense samples while it increased for loose samples. Additionally, cyclic deviator stress ratio of the mixtures was estimated using the concept of equivalent granular void ratio.