• Journal of the Korean Geographical Society
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• v.35 no.1
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• pp.17-38
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• 2000

The marine terraces often offer come important clues to understand the topographic development during the Quaternary and the present landforms in korea. We examined the mechanism of the marine terraces formation along the coast from Samjung-Ri(community), Guryongpo-Eup(county) to Haseo-Ri, Yangnam-Myun(county), Gyungju-Si(city). Among the various but unique factors of the given coastal environment, which should contribute to the marine terraces formation together, we focused on five possible factors for the present stydy. Geologic difference in bedrocks, protrusion degree of coastiline, topological relief of sea-bottom, fluvial characteristics on land, and pattern of the waves appeared to act cooperatibely on the terrace formation of Southeastem coast in korea, while the fluvial characteristics seemed play a significant but localized role in it. Wide distribution of middle surfaces on the coast of Samjungri-Janggilri could be due to the concentration of the high waves and the weakness of the Tertiary volcanic rocks. For the sporadic distribution of the terraces on the coast of Gupungri-Gyewonri, it seemed attributable to the erosion -susceptible weak bedrock, the coastline of inner bay, shallow sea-bottom with the gentle relief, and other fluvial characteristics with the low divides. Together with the geologic difference in bedrock, other factors including protrusion degree of coast, topological relief of sea-bottom, and the transportation loads by the stream Daejongchon are believed to act cooperatively on the mechanism of the marine terraces formation on the coast of Duwonri-Upchonri.

• Korean Journal of Ichthyology
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• v.29 no.4
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• pp.267-271
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• 2017

Diel changes in feeding activity of juvenile Pacific herring, Clupea pallasii were investigated throughout the analysis of stomach contents of 301 fishes collected from the southeastern coast of Korea. Fish samples were collected every 3 hour over a 24 h period in summer using small bottom trawl. The ratio of empty stomach, stomach fullness, stomach contents index (SCI) and stomach fullness index (IF) of juvenile C. pallasii were varied markedly with day/night changes. The ratio of empty stomach tended be higher during nighttime, while the other values were higher at daytime, with showing peak before sunset. During daytime, the stomach contents mainly were made up of copepods and euphausiids, while the diets at midnight were composed of nearly digested and unidentifiable items.

• Journal of Ocean Engineering and Technology
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• v.10 no.2
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• pp.120-135
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• 1996

The characteristics and fluctuations of structures and spatial distributions of thermal fronts and warm eddy in the Southeastern part of the East sea are discussed based on the data collected by the Naval Academy, Korea during Feb. 6-9, May 9-19 and Oct. 12-18, 1995. The thermal fronts existed very often at the sea off the Pohang-Ulsan, The generation of the thermal front is related with the development of the North Korea Cold Current. The warm eddy is located in the central part of the Ulleung basin where the local depth exceeds 1500m. This warm eddy is a major contributor to mass transport in the northern part of the East Sea. It is evident that knowledge of warm eddy is important in understanding the circulation in the western part of the East Sea.

• 한국지구물리탐사학회:학술대회논문집
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• 2011.10a
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• pp.127-130
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• 2011

• Economic and Environmental Geology
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• v.28 no.6
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• pp.587-597
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• 1995

Two distinct precious-metal mineralizations actively occur at central and southeastern Korea which display consistent relationships among geologic, geochemical and genetic environments. A large number of preciousmetal vein deposits in the central Korea occur in or near Mesozoic granite batholiths elongated in a NE-SW direction. Whereas, gold and/or silver deposits in the southeastern Korea occur within Cretaceous volcanic and sedimentary rocks. However, most of the precious-metal deposits in the southeastern Korea show characteristics of the silver-rich deposits than the gold-rich deposits in the central Korea. Two epochs of main igneous activities are recognized: a) Jurassic Daebo igneous activity between 121 and 183 Ma, and b) Cretaceous Bulgugsa igneous activity between 60 and 110 Ma. Precious-metal mineralization took place between 158 and 71 Ma, coinciding with portions of the two magmatic activities. Contrasts in the style of mineralization, together with radiometric age data and differences in geologic settings reflect the genetically variable natures of hydrothermal activities from middle Jurassic to late Cretaceous time. The compilation and re-evaluation of these data suggest that the genetic types of hydrothermal precious-metal vein deposits in the central and southeastern Korea varied with time. The Jurassic and early Cretaceous mineralizations are characterized by the Au-dominant type, but tend to change to the Au-Ag and/or Ag-dominant types at late Cretaceous. The Jurassic Au-dominant deposits commonly show several characteristics; prominent associations with pegmatites, simple massive vein morphologies, high fmeness values in ore-concentrating parts, and a distinctively simple ore mineralogy such as Fe-rich sphalerite, galena, chalcopyrite, Au-rich electrum, pyrrhotite and/or pyrite. The Cretaceous precious-metal deposits are generally characterized by some- features such as complex vein morphologies, low to medium fmeness values in the ore concentrates, and abundance of ore minerals including Ag sulfosalts, Ag sulfides, Ag tellurides and native silver. Mineralogical and fluid inclusion studies indicate that the Jurassic Au-dominant deposits in the central area were formed at the high temperature (about $300^{\circ}$ to $500^{\circ}C$) and pressure (about 4 to 5 kbars), whereas mineralizations of the Cretaceous Au-Ag and Ag-dominant deposits were occurred at the low temperature (about $200^{\circ}$ to $350^{\circ}C$) and pressure (<0.5 kbars) from the ore fluids containing more amounts of less-evolved meteoric waters.

• Journal of Environmental Science International
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• v.12 no.8
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• pp.881-889
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• 2003

Spatial and vertical variations of butyltins(BTs) were investigated in polluted sediments from Jinhae, Busan, Ulsan and Yeongil Bays located in the southeastern part of Korea. Tributyltin(TBT) as a dominant species was detected in 18 of the 20 surficial sediments, and TBT levels were lower that for those in heavily polluted areas worldwide, ranging from 12 to 766 ng Sn/g dry wt. Distribution of TBT levels among bays was not significantly different (p=0.286, ANOVA). The horizontal distributions observed at 20 sites suggests that TBT concentrations are still high in polluted sites around harbors and industrial complexes. The sedimentary records a peak in the early 1990s in Jinhae Bay, in the mid 1980s in Ulsan Bay and in the late 1970s in Yeongil Bay except for Busan Bay which had a homogenous profile. In paricular, TBT at the surface sediments of four core samples still had high levels. From the horizontal and vertical results, it could be assumed that TBT inputs in the sediments were not reduced significantly compared to past levels. The annual accumulation rates estimated using the sedimentation rates and the concentration of surficial sediments exhibited that the accumulation rate of Ulsan Bay was greater than the rates for Jinhae and Yeongil Bays.

• Journal of the Korean earth science society
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• v.18 no.6
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• pp.493-499
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• 1997

Grain size analysis have been made for the carbonate-detrital mixed sediments on the continental shelf off the southeastern coast of Korea. The detrital components are well-sorted with mean grain size between 2-3 phi. The detrital components are thought to be deposited in the beach environment during the glacial times when the sea level was low, representing typical 'relict' sediments. Most of the carbonate components consist of shell fragments, and are deeply weathered. They are also interpreted as the relict components that were deposited in the shallow marine environment. The carbonate fraction are coarser-grained and poorly sorted compared to the detrital component. The carbonate components are thought to have experienced the continuous environmental control of fragmentation and selective size sorting after the deposition.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.37 no.4
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• pp.312-322
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• 2004

Physical and geoacoustic properties of inner shelf sediment in the South and Southeastern Seas of Korea have been studied based on six piston core samples. The sediments are largely composed of homogeneous mud except the core from the southeasternmost part of the area. Both physical and geoacoustic properties and mean grain size are relatively uniform with sediment depth, suggesting little effect of sediment compaction and/or consolidation. Mean grain size appears to be the most Important variable to determine the physical and acoustic properties. In contrast, the attenuation shows more or less fluctuations. Correlations between physical properties and sediment texture show slight deviations from those of the compared data, caused by the difference of sedimentary processes, mineral composition, and the difference of measurement system. In particular, the velocity is lower (approximately 20-30 m/s) than that of the previous data measured in the same area. This is probably due to the difference in velocity measurement system (particularly, error by a length of sample). We propose new relationships for physical and geoacoustic characteristics of shelf sediment in the study area.

• Journal of The Geomorphological Association of Korea
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• v.24 no.4
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• pp.13-25
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• 2017

To reconstruct the paleo-temperature quantitatively and to overcome limitation of traditional qualitative pollen analysis, this study was performed pollen analysis using the modern surface soil at Yulha-dong, Gimhae-si of southeastern part of Korean peninsula. Canonical Correspondence Analysis(CCA) was done to identify the most important environment variable about composition of modern surface pollen sample. Also, Weighted Average-Partial Least Square(WA-PLS) was analyzed to obtain modern surface pollen-temperature transfer function. The transfer function was applied to the results of qualitative fossil pollen analysis at Yulha-dong, Gimhae-si, Sampyung-ri, Ulsan-si and Taewha-dong, Ulsan-si. Therefore, the paleo-temperature was reconstructed during the Holocene since 6,200 yr BP. According to the results of the research, it is $1{\sim}2^{\circ}C$ lower than the current average annual temperature at the study area in 6,200 yr BP, since then it increased to the same level to the current temperature and decreased again until 2,600 yr BP. From the 2,600 yr BP, the temperature was fluctuated to the present.

• 한국석유지질학회:학술대회논문집
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• spring
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• pp.15-21
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• 1998

Sparker profiles and sediment cores collected from the Korea Strait show a distinct pattern of stacked prograding wedges consisting of three distinct units. These wedges are interpreted as the lowstand deposits formed during glacioeustatic sea-level lowstands. Repeated sea-level falls during late Pleistocene with high sediment discharge from the paleo-Nakdong River system resulted in the formation of thick lowstand wedges.