• 한국해양학회지
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• v.25 no.4
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• pp.182-188
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• 1990

The sedimentation processes and heavy metal distributions at the Nakdong estuary were investigated during October 1987 and September 1988. The depositional sedimentary environment of the studied area was estuarine environments and was divided into three provinces depending on its textural parameters such as barrier, tidal falt, and water passes. The relationship between the textural parameters showed that the barrier was under strong wave action, that the tidal flat was under relatively weak wind-driven currents, and that the water passes were under strong and continuous tidal currents. Each environments was resulted from different transport mechanism. the sand barrier sediments were transported by all three populations including suspension, saltation, and bed load, and water pass-deposited sediments were by the bad load with some suspension population. In water mass over the studied area, the concentrations of heavy metals including Cu, Cd, $Cr^{+6}$, Pb and Zn were recorded to be 27.8, 6.7, 20.4, 16.3, and 37.3 ppb in their highest concentrations, respectively. and those in sediments were 20.0, 1.65, 25.4, 15.4, and 132.0 ppm, respectively. The total up take factored of Cu, Cd, $Cr^{+6}$, Pb, and Zn by V. Muller (corbicula fluminea) were 1600, 310, 310, 490 and 7900, respectively.

• Ocean and Polar Research
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• v.45 no.2
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• pp.89-102
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• 2023

Climate and environmental changes in the Arctic Ocean due to global warming have been linked to extreme climate change in mid-latitude regions, including the Korean Peninsula, requiring a better understanding of the Arctic climate system based on the paleo-analog. This review introduces three paleoenvironmental research cases using neodymium isotopes (¹⁴³Nd/¹⁴⁴Nd, ε_Nd) measured on two different fractions of marine sediments: silicate-bound 'detrital' and Fe-Mn oxide-dominated 'authigenic' fractions. In the first case, detrital ε_Nd in core HH17-1085-GC on the continental shelf off northern Svalbard was used for tracing changes in sediment provenance and associated glacier behavior over the last 16.3 ka. The second case showed the potential use of authigenic ε_Nd as a quasi-conservative water mass tracer. Three prominent ε_Nd peaks and troughs observed in core PS72/410-1 from the Mendeleev Ridge in the western Arctic Ocean over the past 76 ka suggested episodic meltwater discharge events during 51~46, 39~35 and 21~13 ka BP. The last case proposed the use of the difference between authigenic and detrital ε_Nd as a proxy for reconstructing glacier fluctuation. The idea is based on the assumption that enhanced glacial erosion during glacier advances can supply sufficient freshly-exposed rock substrate for incongruent weathering, potentially leading to greater isotopic decoupling between bedrock and dissolved weathering products as recorded in detrital and authigenic ε_Nd, respectively. Thus, it would be worthwhile to take advantage of sedimentary ε_Nd to improve our understanding of past environmental changes in polar regions.

• Journal of the Korean Geophysical Society
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• v.2 no.2
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• pp.91-99
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• 1999

A high-resolution seismic profile acquired across the northeastern boundary of the Pungam Basin, one of the Cretaceous sedimentary basins in Korea, has been interpreted to delineate subsurface geological structures across the basin boundary. We identified boundary faults and unconformity surfaces of the basin and divided sediment body into three seismic depositional units (Units I, II, and III from youngest to oldest). Inferred from fault geometry and type, northeastern part of the Pungam Basin has been formed by a strike-slip fault whereas the normal faults near the boundary were formed by transtensional movement along a fault zone. A 350-400 m thick sediment layer is overlying the Precambrian gneiss. Bedding planes of Unit III are dipping westward and are closely related to an anticline in the acoustic basement. Unit II is also tilted westward, suggesting that the eastern part of the fault zone was uplifted after deposition of lower part of the sedimentary body. Afterward, the uplifted sediment layers were eroded and transported to the western part of the basin. Chaotic reflection pattern of sedimentary Units II and III may suggest that strike-slip movement along the fault zone deformed basin-filled sediments.

• Journal of The Geomorphological Association of Korea
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• v.20 no.4
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• pp.51-70
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• 2013

The characteristics of deposits formed by the Daejon-cheon and Soobuk-cheon, dissecting the mountains such as Byungpung Mt. and Samin Mt. in western part of Damyang county, Jeonmam province. Results from field survey and bore hole logging by KIGAM are used in interpreting depositional environment, in this study. By the result of deposits near of the channels Daejon-cheon and Soobuk-cheon, and main channel of Youngsan River, the depth of sediment layers in this area is 4~7m, far thinner than formerly estimated. Weathered material of local rocks forms the base of the sedimentary layers. It can be assumed that the location channel of the Youngsan river has been stable ever since the start of the sedimentary events. Sediment particles of tributaries are angular than those of Youngsan River. Particles are larger and sorting is poor. It is interpreted as mount flash flood deposits. Main sources of sediments at the valley bottom or deposition dominated area are the terrace deposits or slope deposits over the gentle foot-slope or front of surrounding mountains. Some particles show polygonal cracking on the surface originated from the strong chemical weathering, while most of these has high angularity. It means various geomorphic processes operate to produce and transport the particles in this area.Isolated hills within the sedimentary plains are made with weathered materials of local bedrock. In the case of foot-slope of the hills, thin sedimentary layers are found. So it can be concluded that surface features of deposition zone of the Daejon-cheon and Soobuk-cheon is formed by the filling of lower part of the valley and its feature partly controlled by the relief of the weathering front.

• Journal of the Korean Society for Marine Environment & Energy
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• v.19 no.4
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• pp.297-309
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• 2016

This study was carried out to investigate the differences in sedimentary environments and benthic polychaete communities between farming grounds and natural habitats (non-farming ground) in Gamak Bay. Sampling stations of natural habitats were evenly distributed in the entire bay. And mussel farm, oyster farm and ark-shell farm were selected as farming grounds. Dominant sedimentary facies was mud in most sampling stations of farming grounds and natural habitats. However organic contents were higher in the farming grounds than natural habitats of the bay. The species number and mean density of polychaetous community in the natural habitats were greater than those from the farming grounds. Lumbrineris longifolia, known as potential organic enrichment indicator species, was first dominant species both in farming grounds and natural habitats of the bay. However, the next dominant species consisted of different species between two benthic habitats. As a result of community analysis using cluster analysis and nMDS, the natural habitats were divided into several station groups, but most of stations in farming grounds were clustered into one group. Pearson' correlation analysis and PCA showed high relationships between sedimentary environmental factors and benthic polychaetous community in natural habitats, but low or no relationships in farming grounds. That means benthic polychaetous community established in farming ground was under unusual condition such as high input of organic matter. Thus it is necessary to improve the benthic environmental quality of the farming grounds as well as the north-western inner part in Gamak Bay through long-term monitoring efforts.

• Journal of Wetlands Research
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• v.23 no.3
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• pp.213-223
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• 2021

To understand the sedimentary environment of Scirpus planiculmis habitat (Myeongji and Eulsuk tidal flats) in the Nakdong Estuary, this study analyzed the statistical parameters (sorting, skewness, and kurtosis) of grain size data and the major (Al, Fe, Mn, Mg, Ca, Na, K, Ti, and P), minor (Li, Sc, V, Cr, Co, Ni, Cu, Zn, Sr, Zr, Cs, Pb, Th, and U), and rare earth elements (REEs) in sediment cores. For Myeongji, the sediment structure of the upper part of the cores was poorly sorted, more finely skewed, and more leptokurtic due to construction of the West gate. By contrast, the Eulsuk cores all differed due to the contrasting floodgate operation patterns of the West and East gates. The linear discriminate function (LDF) results corresponded to the statistical parameters for grain size. At the Eulsuk tidal flat (sites ES05 and ES11), elemental distributions were representative of Al-, Fe- and Ca-associated profiles, in which the elements are largely controlled by the accumulation of their host minerals (such as Na- and K-aluminosilicate and ferromagnesium silicate) and heavy detrital minerals at the sites. Detrital minerals including the aluminosilicates are major factors in the elemental compositions at ES05, diluting the REE contents. However, clay minerals and Fe-oxyhydroxides, as well as REE-enriched heavy minerals, appeared to be controlling factors of the elemental composition at ES11. Therefore, the mineral fractionation process is important in determining the elemental composition during sedimentation, which reflects the depositional condition of riverine-saline water mixing at both sites.

• Proceedings of the Korean Geotechical Society Conference
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• 2003.03a
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• pp.747-752
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• 2003

This study was carried out to understand the stratigraphy and depositional environment of clayey soils that distributed in the Gadeok-do area, Kimhae plain (Nakdong estuary). For the study, SPT core sampling and magnetic susceptibility analysis were conducted. Soils in study area is classified into five sedimentary facies ascending order; sand/gravel. clay, sand/gravel, clay, interbedded sand and silty clay. Analysis of magnetic susceptibility for Gadeok-do clayey soil reveals that depositional process and environment can be divided into upper, middle and lower layer, and they are closely related to the sea level change since late Quaternary.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2004.04a
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• pp.492-494
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• 2004

The purpose of this study is to investigate the hydrochemical characteristics of groundwater in the Umsung area, and to elucidate the effect of host rock type, well depth and mineralization zone on the groundwater chemistry, We carried out chemical analysis, isotopic analysis, statistical analysis of Box-Whisker and trigging analysis for this study. The chemical and isotopic compositions of the groundwater is distinguished into two areas according to host rocks(Cretaceous sedimentary rocks and Jurassic granite) and recharge altitude, and is not greatly influenced by mineralization zone of the mines.

• Ocean and Polar Research
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• v.28 no.2
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• pp.67-78
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• 2006

Six surface sediments from two offshore transects of Ulsan and Gampo, on the southeastern margin of Korea were taken for sediment and foraminiferal analyses. Sedimentary processes are dominated by reworking and resedimentation from storms in the area off Ulsan and hemipelagic suspension settling in the area off Gampo. Eighty-four foraminiferal species were identified in total assemblages, including 33species of living populations and 9 species of planktonic foraminifera. The characteristics of foraminifera showed differences of offshore environments between Ulsan and Gampo. The number of living species, species diversity and equitability in Gampo offshore area had higher values than those in Ulsan offshore area. However, planktonic/benthic(P/B) ratio showed higher in the Ulsan offshore area. The species diversity indices and P/B ratio indicated that environmental stability and surface-ocean productivity in the Gampo offshore area were relatively higher than the Ulsan offshore area. The difference of species compositions is useful for interpreting the paleoenvironments in mud deposits of the southeastern margin of Korea.

• Journal of Soil and Groundwater Environment
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• v.21 no.6
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• pp.80-86
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• 2016

Earthquakes of M5.1, M5.8 and M4.5 occurred in September 12 and 19 respectively in Gyeongju, Gyeongbuk Province. Theses earthquakes inflated fears of people and highlighted necessity of detailed countermeasures because we have considered our country is safe to earthquakes. In the meanwhile, earthquake also impacts groundwater and thus it was recently reported that the Gyeongju Earthquakes affected groundwater there. This study evaluates daily groundwater data collected from five national groundwater monitoring stations (Geoncheon, Sannae, Oedong, Yangbuksin, Cheonbuk) in Gyeongju. The analysis revealed that only groundwater level of bedrock monitoring well hosted in andesite exhibited earthquake impact while no wells in the other four stations hosted in sedimentary rocks showed substantial responses to the earthquakes. This may be derived from the difference of seismic velocity of hosting rocks as well as epicenter distance. Special interest on groundwater monitoring is required to predict earthquakes as precursory phenomena.