• The Korean Journal of Quaternary Research
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• v.5 no.1
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• pp.47-61
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• 1991

Textural analysis of gravels of raised beach (old beach) in the Weaver Peninsula, King George Island, Antarctica has been carried out as a first part study among 20 other sites surveyed in the Weaver Peninsula and Barton Peninsula, King George Island. The raised beach described as WP-5 in this paper is 3.95 m higher than the present beach in elevation. And it is described as old beach. The beach shows typical subenvironment, that is, beach berm and beach face. Mean size, mean roundness and mean sphericity of gravels from beach berm are -4.10ø, 0.44 and 0.66 respectively. However, mean size, mean roundness and mean sphericity from beach face are -4.23ø, 0.41 and 0.67 respectively. In particular, it seems to be worthy to note the differences of textural parameters between Antarctic glacio-marine beach gravels and temperate and normal marine beach gravels. Under such conception the present study wishes to show only textural parameters, i.e., size, roundness, sphericity and shape obtained from the analysis of Antarctic glacio-marine beach gravels.

• The Korean Journal of Quaternary Research
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• v.4 no.1
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• pp.41-57
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• 1990

Gravel shapes of the terrace gravel sequences are compared with the present river gravels and beach gravels in the Pohang and its surrounding areas. Seventeen gravel textural parameters are divided into 5 groups based on R-mode factor analysis. Among them, three parameters (RDm, MPSm, SZstd) are selected for a test of discriminant possibility of palaeoenvironment of the terrace gravel deposits. Marine gravels are in the range of 0.49 to 0.75 in mean roundness, 0.46 to 0.78 in mean maximum projection sphericity and 0.39 to 1.85 in standard deviation of size, whereas river gravels are 0.28 to 0.51 in mean roundness, 0.66 to 0.72 in mean maximum projection sphericity and 1.04 to 1.81 in standard deviation of size. For practical access to the palaeoenvironment discrimination, a bivariant diagram between mean roundness and mean maximum projection sphericity is the most effective. The marine terrace gravels are plotted within the variation range of present beach gravels and show 0.49 to 0.71 in mean roundness and 0.59 to 0.66 in mean maximum projection sphericity. The gravels of river terrace vary within the range of gravels derived from present river bed and are characterized as 0.36 to 0.48 in mean roundness and 0.66 to 0.71 in mean maximum projection sphericity.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2011.05a
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• pp.55-55
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• 2011

자동차 후드, 라디에이터그릴(R/Grill), 범퍼, 아웃도어핸들 등 도장 도금 부품소재의 치핑시험법을 재정립 하였다. 시간에 따른 열화(100~1500hr)에 따라 도막 경도, 탄성율, Tg, 층간 부착성 등 물리적 특성 관찰하였고 제논시험기를 이용하여 재현시험을 행하였다. 국내에서 유일한 싱글/멀티 치핑기에 의한 치핑인자(속도, 비석, 각도 등) 분석 및 실제 주행차량의 분석을 통한 치핑의 주요원인을 밝혀냈다. 외산과 국산을 비교하여 속도별 치핑현상을 파악하였고, 마모 마찰열의 상승을 최소화와 원마도(R)의 최적조건을 찾아내었다.

• Journal of The Geomorphological Association of Korea
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• v.21 no.4
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• pp.109-120
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• 2014

This study is an analysis on gravel and sand of sand-gravel bar that stretches variously in the Duchon stream basin, which is one of Hong-Cheon River(a well-developed sand-gravel bar in upstream river)'s upper stream basin. The purpose of this study was to understand the characteristic of the stream's topographic development that variously occur in the small basin by comparing the differences between the aspects of development and the sediment of sand-gravel bar in each section and by examining the transition of sediments moving from upstream to downstream. Through the analysis on the roundness and flatness of gravel, we observed an irregular trend following the increase in supply of granite gravel and gneiss gravel as we traveled downstream. As for the aspect of change in sand's grain size, the overall ratio of medium-coarse sand was very high, but the results showed no big difference in the change following the inflow of stream from the main stream section to the gneiss and granite zone.

• Journal of The Geomorphological Association of Korea
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• v.18 no.4
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• pp.177-191
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• 2011

This paper describes a dune field on shoreline of Young Gwang. To clarify geomorphic characteristics, made an analysis of grain size of the sand sediments samples and surface texture of quartz grains, and field survey. The following results were obtained : 1) Young Gwang sand dune is taking to pieces by human impact, and dose not move ahead the process of sand dune. 2) there was a turbulence of sand sediments outcrops saying to the cryoturbation that represents cold climatic environments, 3) Constituents of sand dune are mainly fine and very fine sand(2.5~4.5Φ) consisted by quartz and feldspar. Young Gwang sand grians have some analogy with different sites in west coast 4) In surface texture, roundness is thought to have been formed sub-angular, and some V cracks represented mechanical weathering environments. Especially, the dune environment has significant cultural and archaeological values arising from the occupation of human in the past. Those areas where occupation is known provide a valuable source of past records relating to human settlement.

• The Journal of the Petrological Society of Korea
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• v.8 no.1
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• pp.14-23
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• 1999

The northeastern part of the Gyeongsang Basin is widely covered by the Cretaceous Hayang Group (Aptian to Albian). The Hayang Group consists of the IIjig. Hupyeongdong, Jeomgog, and Sagog formations. Heavy mineral analysis was carried out to define the possible source rocks of the Haynag Group snadstones. Heavy minerals separated from IIjig, Hupyeongdong, and Jeomgog sandstones are hematite, ilmenite, leucoxene, magnetite, pyrite, actinolite, andalusite, apatite, biotite, chlorite, epidote, garnet, hornblende, kyanite, monazite, muscovite, rutile, sphene, spinel, staurolite, tourmaline, and zircon. Based on their close association and sensitiveness, the heavy mineral assemblages can be classified into 6 syutes: 1)apatite-green tourmaline-sphene-colorless/yellowish zircon; 2) colorless garnet-epidote-rutile-brown tourmaline; 3) rounded purple zircon-rounded tourmaline-rounded rutile; 4) augite-hornblende-color- less zircon; 5) epidote-garnet-sphene; and 6) blue tourmaline. The possible source rocks corresponding to each assemblage are 1) granitic rocks; 2) metamorphic rocks (schist and gneiss) ; 3) older sedimentary rocks; 4) andesitic rocks; 5) metamorphosed impure limestone; and 6) pegmatite, respectively. Previous paleocurrent data suggest that the sediments of the study area were mainly derived from the northeastern to southeastern directions. Thus, the most possible source areas would be the east extension part of the sobaegsan metamorphic complex to the northeast and the Cheongsong Ridge to the southeast.

• Journal of the Korean Geotechnical Society
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• v.28 no.8
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• pp.21-29
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• 2012

At-rest lateral stress coefficient that is used for the evaluation of geotechnical structures such as foundations and retaining walls plays a significant role in the analysis and design, as a state variable of in-situ stress condition. In the widely applied Jaky's Ko equation stress condition can be inferred from the internal friction angle obtainable from the laboratory experimentation whereas the eguation mares it challenging to evaluate the influences and criteria of particle characteristics which is essential for the application of friction angles in practices. Thus, this study experimentally explored the behaviors of Ko depending on the relative density, particle shape, and surface roughness effect during a range of loading stages. The Ko values of Jumumjin sand, glass beads, and etched glass beads were measured using a customized Ko device housing strain gauges during loading-unloading-reloading steps, and the effect of dominant factors on Ko is analyzed. Results show that the high Ko prevails for both round and angular specimens with low relative density and the surface roughness has a nominal effect. The angular particles exhibit low Ko for specimens with similar relative density. The characteristics of relevance between Ko and friction angles with varying relative density are also investigated based on the experimental results using empirical correlations and previously reported values.

• Journal of the Mineralogical Society of Korea
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• v.20 no.4
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• pp.289-302
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• 2007

Separation process of heavy minerals was performed with sand from Dunjang beach of Jaeundo, Shinangun, Chonnam, and the feasibility study separating heavy minerals was carried out, and their properties were studied. Samples were selected in three parts, which were upper part, middle part and lower part, with depth. Samples of heavy mineral groups separated with the spiral separator were chosen as starting materials, and they were separated with 3 times of table separation. Heavy minerals presenting in this area were ilmenite, zircon, rutile, anatase, monazite, and xenotime. In the results of 3 times of table separation, minor content of quartz, orthoclase, albite and muscovite were existed as gangue minerals. Accordingly, we concluded that additional specific gravity separation was needed. In the results of separation of heavy minerals by hand picking, it was confirmed that heavy minerals had various genesis because of their various roundness and color.

• Journal of Gifted/Talented Education
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• v.23 no.6
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• pp.881-898
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• 2013

The purpose of this study was to compare the difference of semantic network about sedimentary environment between science gifted students and non-gifted students through field trip. The fifteen high school science gifted students and non-gifted students were participated in the field trip for this study. The geological field trip was performed in Chaseokgang, which suitable learning place for sedimentary environments. Data included field trip observation and students' inquiry activity reports. The inquiry activity reports were analyzed using the semantic network analysis method. The results of this study were as follows: First, the semantic network of science gifted students was larger and complex structures than that of the non-gifted students. Second, science gifted students were interpreted that changes of sedimentary environment was connected with the sorting and the roundness. On the other hand, semantic network of non-gifted students were become fragmented because they were not interpreted sedimentary environment related to scientific concepts.

• Journal of The Geomorphological Association of Korea
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• v.18 no.1
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• pp.101-112
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• 2011

Coastal terrace was developed at 7.2m height near Shinchon village in Geoje Island. It is located on the east side of southern coast in Korean Peninsula, where sea-level changes caused by ebb and flow of the tide, embayment are relatively low. Due to the breccia layer by mass-movement, dark grayish clayey formation, marine origin's rounded gravel are deposited sequentially in a cross-section of coastal terrace, so it provides a good example which understand Holocene sea level changes to determine the effect on the various sedimentary environments. For the purpose of identifying the morphogenetic process, Grain size, Roundness, XRD, AMS dating analysis was attempted. As a result, after last glacial age, Holocene sea level rise to +5.6m(4,740±100yrs BP). At that time, various geomorphological features are considered to be formed.