• Journal of the Mineralogical Society of Korea
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• v.22 no.1
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• pp.49-61
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• 2009

We studied the mineral composition and mineral distribution pattern of 131 surface sediments collected at the cruise in 2000 and 2007 from Southeastern Yellow Sea, South Sea of Korea and Southern part of Jeju Island. Mineral compositions of surface sediments were determined using the quantitative X-ray diffraction analysis. Surface sediments were composed of rock forming minerals (quartz 37.4%, plagioclase 11.7%, alkali feldspar 5.5%, hornblende 3.1%), clay minerals (illite 19.2%, chlorite 4.7%, kaolinite 1.8%) and carbonate minerals (calcite 10.7%, aragonite 3.4%). Distribution of clay minerals is very similar with fine-grained sediments, and especially same as the distribution of HSMD (Hucksan Mudbelt Deposit), SSKMD (South Sea of Korea Mudbelt Deposit) and JJMD (Jeju Mudbelt Deposit). The coarse sediment seemed to be relic sediment during the last glacial maximum and mainly consisted of rock forming minerals. Whereas the fine sediments mainly composed of clay minerals. Based on the clay mineral composition, main ocean current and geographical factor, HSMD and SSKMD might have derived from the rivers around the Korean Peninsula. However, JJMD is complex mudbelt deposit, which formed by Korean rivers and oceanic sediments.

• Ocean and Polar Research
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• v.41 no.4
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• pp.265-274
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• 2019

To trace the provenance of fine-grained sediments in response to the growth and retreat of glaciers (i.e., Ross Ice Sheet) that affects the depositional process, various kinds of analyses including magnetic susceptibility, granulometry, and clay mineral composition with AMS ¹⁴C age dating were carried out using a gravity core KI-13-GC2 obtained from the Central Basin of the Ross Sea continental margin. The sediments mostly consist of silty mud to sand with ice-rafted debris, the sediment colors alternate repeatedly between light brown and gray, and the sedimentary structures are almost bioturbated with some faint laminations. Among the fine-grained clay mineral compositions, illite is highest (59.1-76.2%), followed by chlorite (12.4-21.4%), kaolinite (4.1-11.6%), and smectite (1.2-22.6%). Illite and chlorite originated from the Transantarctic mountains (metamorphic rocks and granitic rocks) situated to the south of the Ross Sea. Kaolinite might be supplied from the sedimentary rocks of Antarctic continent underneath the ice sheet. The provenance of smectite was considered as McMurdo volcanic group around the Victoria Land in the western part of the Ross Sea. Chlorite content was higher and smectite content was lower during the glacial periods, although illite and kaolinite contents are almost consistent between the glacial and interglacial periods. The glacial increase of chlorite content may be due to more supply of the reworked continental shelf sediments deposited during the interglacial periods to the Central Basin. On the contrary, the glacial decrease of smectite content may be attributed to less transport from the McMurdo volcanic group to the Central Basin due to the advanced ice sheet. Although the source areas of the clay minerals in the Central Basin have not changed significantly between the interglacial and glacial periods, the transport pathways and delivery mechanism of the clay minerals were different between the glacial and interglacial periods in response to the growth and retreat of Ross Ice Sheet in the Ross Sea.

• Journal of the Korean Society for Marine Environment & Energy
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• v.13 no.3
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• pp.198-205
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• 2010

The purpose of this study is to investigate the characteristics of the grain size distribution and organic matters to understand the current status of the tidal flat sediment for efficient management of Suncheon Bay. We investigated the characteristics of the surface sediments in the mouth area of the Suncheon Bay at fifteen stations in April and July, 2009. Specific conclusions were as follows. The sediments in the most part of tidal flat was shown as muddy facies(clay and silt contents was more than 90%), whereas in the tidal river affected by water flow from the Dongstream was shown as sandy facies. The analyzed values of the tidal flat sediment were in the range of $1.9{\sim}3.8{\phi}$(mean $2.5{\phi}$) for sorting, and -1.5~3.2(mean -0.3) for skewness, and 1.5~14.1(mean 3.9) for kurtosis. So we knew that the tidal flat sediments in the Suncheon Bay was mainly composed by fine-grained sediment. Erosion was happened in the tidal river, whereas sedimentation was occurred in the tidal flat. The most of organic matters was derived from the Dongstream. Total organic matters shown as ignition loss was 5.75%, COD and $H_2S$ values were lower than the eutrophication level(COD; 20.0 mg/g dry, $H_2S$; 0.2 mg S/g dry). From our research the tidal flat of the Suncheon Bay is relatively fine, but a part of the flat was exceed the environmental standard. So we have to establish effective countermeasures to reduce the organic matters and nutrients derived from stream for environmental preservation of the Suncheon bay and conduct scientifically sustainable monitering for streams flowing into Suncheon Bay and tidal flat.

• Journal of the Mineralogical Society of Korea
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• v.23 no.1
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• pp.15-23
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• 2010

The absolute clay mineral compositions and regional distribution of the 131 bulk marine surface sediments around the Jeju Island was compared to their relative compositions and distribution using quantitative X-ray diffraction analysis. Average absolute clay mineral composition is illite 15.3% (0.5~40.5%), chlorite 2.6% (0~7.9%), and kaolinite 1% (0~5.6%). Total contents of the clay minerals are very high in the South Sea of Korea, northwestern part and southern offshore of Jeju Island. The average relative composition is illite 70.9% (16.7~89%), chlorite 21.5% (8.4~68.5%), and kaolinite 7.6% (0~29.3%). Relative illite contents are high in the northwestern and southeastern part of study area, and southern part of Jeju Island. Chlorite contents are high in the eastern part of study area and western part of Jeju Island. Kaolinite contents are high in the western and southern part of Jeju Island, and southern offshore of Jeju Isand. Absolute Distribution patterns are very similar to those of fine-grained (from clay to silt) sediment, whereas relative distribution patterns do not show any relationship with those of fine-grained sediment.

• Journal of the Korean Society for Marine Environment & Energy
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• v.19 no.4
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• pp.247-258
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• 2016

Physical and acoustic properties of sediment on the southwestern Taean Penisula, the Yellow Sea, were studied using eight piston cores. The sediments in the study area are largely composed of sand which has been deposited with sea-level change after LGM(Last Glacial Maximum). After the sea-level rise, fine-grained sediments discharged from Keum River and neighboring coast area were deposited as muddy sand or sandy mud. Results of these sedimentary environment in this area, the texture of sediments are different from place to place with variable horizontal and vertical distribution of physical and acoustic properties. Correlations among the physical, geoacoustic properties, and mean grain size show slight deviations from those of the South Sea in spite of similar pattern. This is probably due to the differences in sedimentary environment, mineral composition, and measurement system.

• Journal of the Korean Geosynthetics Society
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• v.12 no.3
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• pp.87-94
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• 2013

As sediment contamination problems have recently been raised in Korea, the need for technologies to remove contaminants in sediments has increased. Contaminated sediments in Korea has been annually dredged and treated using processes of coagulation/flocculation, sedimentation on barges, dewatered and dried at prepared site, and then disposed at a landfill site, which is very costly, and only a limited landfill space available in Korea. Contaminants in media containing a high percentage of silt and clay sized particles, typically, are strongly adsorbed on the particles and difficult to remove. Particle separation processes that separate the fine clay and silt particles from the coarser sand and gravel and concentrate the contaminants into a smaller volume of sediment that can be further treated of disposed of, are very effective in the post step processes. In this study are to test the feasibility of treating dredged sediments using a hydrocyclone process, and to estimate design parameters for a pilot scale test. A hydrocyclone was operated to separate larger particles from the sediments. It was found that the particle separation was greatly affected by the solid contents and inlet pressure in the hydrocyclone.

• Journal of the Korean GEO-environmental Society
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• v.20 no.4
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• pp.23-29
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• 2019

Heavy rainfall is in causing debris flow by recent climate change and causes much damage in the downstream. The debris flow from the mountainous area runs to the downstream, repeating sedimentation and erosion, and appears as a fluidized soil-water mixture. Continuity equation and momentum equation were applied to analyze the debris flow with strong mobility, and the sedimentation and erosion velocity with fine particle fractions were also applied. This study is to analyze the behavior of debris flow at the downstream end for the variation of the amount of sediments can occur in the upstream of the mountain. Analysis of sediment volume concentration at the downstream end of the channel due to the variance of the length of pavement of the granulated soils resulted in the higher the supply flow discharge and the longer the length of pavement, the greater the difference in the level of sediment concentration and the earlier the point of occurrence of the inflection point. The results of this study will provide good information for determining the erosion-sedimentation velocity rate which can detect erosion and sedimentation on steep slopes.

• Korean Journal of Ecology and Environment
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• v.52 no.4
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• pp.316-323
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• 2019

This study was carried out to investigate sedimentary environment changes in Nakdong River sediments. For this purpose, sediments at six sites upstream of Gangjeong-Goryung Weir in the middle of the Nakdong River were collected before and after the rainy season. Particles size, IL, TOC, TN, TP, and SRP were analyzed for the sediment environment. The changes in the watershed environment before and after the rainy season (precipitation, discharge, and SS concentration) were investigated. After the rainy season, the amount of precipitation and discharge increased more than three times, and the average concentration of SS in the stream increased more than two times. Fine grained sediment and the concentrations of IL, TOC, TN, TP, SRP were increased after the rainy season. As a result of sediment contamination assessment, IL was 19~68% of the reference value, TN and TP were 21~76% and 21~58% of the reference value. The result showed strong correlation between particle size (Silt+Clay) and organic contents of sediment (IL, TOC, TN, TP and SRP). It is considered that the change of the river watershed environment (precipitation, discharge) is an important factor of the change of sedimentation environment.

• Journal of Korea Water Resources Association
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• v.32 no.5
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• pp.547-555
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• 1999

The economical manufacturing process of fluorescent sediments (FS) which makes use of the understanding of coastal sediment path has been suggested with respect to the Lagrangian viewpoint. First, the fluorescent liquids were made by the mixing of the fluorescent materials, acetone, and xylene. Second, the sediments collected in Gamami beach were desalinized by the freshwater washing, dried indoors to protect the fine-sediment scattering, and classified by the sieve analysis. Finally, the FS which have seven different colors were manufactured by the mixing of fluorescent liquids and prepared sediments. The FS were used to figure out the major sediment supply routes of the intake channel in the YoungKwang nuclear power plant. From the field experiments, it was shown that the sediments were suspended and dispersed by the strong seasonal NW wind and the tide, and the sediments in suspension were flowing into the intake channel due to very strong suction speed. All the FS injected in stations were detected in the channel sampling points, thus we concluded that the sediments in suspension and dispersion were flowing into the intake channel from all directions in adjacent coastal zone.

• Journal of the Mineralogical Society of Korea
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• v.20 no.3
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• pp.203-212
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• 2007

Mineral compositions of 89 Yellow Sea surface sediments collected at the second cruise in 2001, were determined using the high resolution X-ray diffractometer and Siroquant v.3.0 program. Yellow Sea surface sediments are composed of major minerals (quartz 57.8%, plagioclase 16.0% and alkali feldspar 10.0%), clay minerals, and calcite. Illite (8.7%) is the most abundant clay mineral, chlorite (2.6%) is the second, and kaolinite (0.6%) is few. however smectite is not detected. Quartz content is very high around the margin of the Yellow Sea, however is very low along the northwest to southeast direction extending from southeast of Sandong Peninsula to southwest of Jeju Island. It has similar distribution pattern with that of coarse sediment (sand). The coarse sediment, is mainly consisted of quartz, may be much supplied from the eastern part and southwestern part of the Yellow Sea. Illite distribution pattern is opposite to that of quartz. It is similar to those of clay and mud particles, therefore it can be suggested that fine sediment may be largely supplied from the northwestern part of the Yellow Sea. It is necessary to continue this kind of investigation, because it is difficult to interpret the sediment provenance of the Yellow Sea only from the result of this study.