• Title/Summary/Keyword: Jeongseon

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Formation Mechanism of Recumbent Fold observed in the Bangrim-ri, Pyeongchang-gun, Korea (평창군 방림리에 발달하는 횡와습곡의 형성 기작)

  • Cheon, Youngbeom;Kang, Hee-Cheol;Ha, Sangmin;Lee, Sun-Kap;Son, Moon;Ryoo, Chung-Ryul
    • The Journal of the Petrological Society of Korea
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    • v.28 no.3
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    • pp.217-225
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    • 2019
  • This study describes a large recumbent fold, which occurs at the north entrance slope of the Batjae tunnel, Pyeongchang-gun, Gangwon-do, and interprets its formation mechanism. The several-hundred-meter scale fold, developed in the Jeongseon Limestone of the Paleozoic Joseon Supergroup, has a nearly horizontal axial plane and its head is facing north. Stretching lineations ($L_1$) observed on the composite foliations of bedding and axial plane cleavage plunge southward at about $10^{\circ}$. Small A-type or eye-shaped sheath folds together with S-shaped asymmetrical folds are often observed in the fold limbs and their axes are nearly parallel to the lineations ($L_1$) within center and rear parts of the fold. It is thus interpreted that the recumbent fold is a large sheath fold produced by the top-to-the-north ductile shearing due to the Songrim orogeny during the late Paleozoic to Triassic.

Basin Evolution of the Taebaeksan Basin during the Early Paleozoic (전기 고생대 태백산분지의 분지 진화)

  • Kwon, Yi Kyun;Kwon, Yoo Jin;Yeo, Jung Min;Lee, Chang Yoon
    • Economic and Environmental Geology
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    • v.52 no.5
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    • pp.427-448
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    • 2019
  • This study reconstructed the paleoenvironments and paleogeography of the Taebaeksan Basin, through a review of the previous researches on sedimentology, paleontology and stratigraphy. This study also carried out a sequence stratigraphic analysis on regional tectonism and sea-level fluctuations on the basin during the Early Paleozoic. The basin broadly occur in the Taebaek, Yeongweol-Jecheon, Jeongseon-Pyeongchang, and Mungyeong areas, Gangwon province, South Korea. The basin-fills are composed mainly of mixed carbonates and siliciclastics, divided into the Taebaek, Yeongweol, Yongtan, Pyeongchang and Mungyeong groups according to lithologies and stratigraphic characteristics. Recently, there are a lot of studies on the provenance and depositional ages of the siliciclastic sequences of the basin. The detrital sediments of the basin would be derived from two separated provenances of the core-Gondwana and Sino-Korean cratons. In the Early Cambrian, the Taebaek and Jeongseon-Pyeongchang platforms have most likely received detrital sediments from the provenance of the Sino-Korean craton. On the other hand, the detrital sediments of the Yeongweol-Jecheon platform was probably sourced by those of the core-Gondwana craton. This separation of provenance can be interpreted as the result of the paleogeographic and paleotopographic separation of the Yeongweol-Jecheon platform from the Taebaek and Jeongseon-Pyeongchang platforms. The analyses on detrital zircons additionally reveal that the separation of provenance was ceased by the eustatic rise of sea-level during the Middle Cambrian, and the detrital sediments of the Taebaeksan Basin were entirely supplied from those of the core-Gondwana craton. During that period, sediment supply from the Sino-Korean craton would be restricted due to inundation of the provenance area of the craton. On the other hand, the Jeongseon-Pyeongchang platform sequences show the unconformable relationship between the Early Cambrian siliciclastic and the Early Ordovician carbonate strata. It is indicative of presence of regional uplift movements around the platform which would be to the extent offset of the effects of the Middle to Late Cambrian eustatic sealevel rise. These movements expanded and were reinforced across the basin in the latest Cambrian and earliest Ordovician. After the earliest Ordovician, the basin was tectonically stabilized, and the shallow marine carbonate environments were developed on the whole-platform by the Early Ordovician global eustatic sea-level rise, forming very thick carbonate strata in the basin. In the Late Ordovician, the Early Paleozoic sedimentation on the basin was terminated by the large-scale tectonic uplift across the Sino-Korean platform including the Taebaeksan Basin.

A Study on the Calcination Characteristics of Jeongseon District's Limestone (정선 지역 석희석의 소성특성 연구)

  • Lee, Jae-Jang;Choi, Jae-Suk;Roh, Beum-Sik;Moon, Young-Bae
    • Journal of Industrial Technology
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    • v.20 no.A
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    • pp.279-283
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    • 2000
  • Lime is one of the world's most useful chemicals and manufactured in various types of kilns, using various fuels. Quicklimes vary in reactivity with water due to variations in the time and temperature calcining process and type of kiln used. Careful attention and control of time and temperature in the calcining process is necessary to insure a highly reactive lime. Excess time and temperature will cause the lime to be over burned. The highest reactivity of quicklime is obtained by calcination of limestone in the particle size of 0.1cm~2cm, calcination temperature of $1000^{\circ}C$, calcination time 90min. It was found by the scanning electron microscopes that pores of quick lime is reducted if the soft burned quick lime is heated continually.

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The Effects of a Raw Diet on Plasma Fasting Glucose Concentration and Immune Function in Streptozotocin-induced Diabetic Rats

  • Kim, Jeongseon;Park, Jun-Young;Kim, Sunggoo
    • Nutritional Sciences
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    • v.7 no.1
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    • pp.3-7
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    • 2004
  • This study was performed to investigate the effect of a raw diet (RD) on blood glucose and immune function in non-diabetic (normal) and streptozotocin (STZ)-induced diabetic rats. Male Sprague-Dawley rats were assigned to four groups (normal control, normal RD, diabetic control and diabetic RD). The control groups and the RD groups were fed an AIN-diet and RD for four weeks, respectively. Weight gain was statistically lower in the RD groups than in the controls. Fasting plasma glucose was significantly lower in the diabetic RD group than in the diabetic control group. The $CD4^+$ T-cell population was higher along with the $CD4^+/CD8^+$ ratio of the mesenteric lymph nodes in the normal RD group compared to the other groups. It can be concluded that RD may reduce the plasma fasting glucose concentration in diabetic rats and improve mesenteric lymph node immune function in normal rats.

The study for water level estimation by rainfall intensity of the upper region in the han river (한강 상류유역의 강우강도에 따른 수위 예측 연구)

  • Choi, Han-Kuy;Choe, Hyun-jong;Baek, Hyo-Seon
    • Journal of Industrial Technology
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    • v.30 no.B
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    • pp.91-98
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    • 2010
  • Recently, there has been enormous damage due to river floodings caused by localized heavy rains. The direct discharge triggered by those torrential rains inflicts severe property damage on the residents of nearby areas. To minimize the possibility of river floodings in case of heavy rains and to predict the possible damage, the management of existing rainfall and water level observatories should be checked and prediction methods based on the characteristics of water usage and floodgate of nearby rivers must be further analyzed. Therefore, this research analyzed the water level change predictions on different spots with a regression equation of rainfall and water levels, using the observation data of the water level observatory in Jeongseon-gun, Gangwon Province and the rainfall observatory which are located on the upper region of the Han river.

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Relational expression of rainfall intensity by the water level fluctuate in the mountain region river of Gang won-do (강원도 산간 지역 하천을 대상으로 한 강우강도에 따른 수위 변동 관계식 작성)

  • Choi, Han-Kuy;Kong, Ji-Hyuk;Lee, Yik-Sang;Cho, Hyun-Jeung;Park, Je-Wan
    • Proceedings of the Korea Water Resources Association Conference
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    • 2011.05a
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    • pp.154-159
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    • 2011
  • As the need for predicting the flood stage of river from torrential downpouring caused by climate change is increasingly emphasized, the study, centered on the area of Gangwon-do Inje-gun and Jeongseon-gun of local river, is to develop peak water level regression equation by rainfall. Through the correlation between rainfall and peak water level, it is confirmed that rainfall according to duration and peak water level have a high correlation coefficient. Based on this, a relational expression of rainfall and peak water level is verified and then the adequacy of the calculated expression is analyzed and the result shows that a very accurate prediction is not easy to achieve but a rough prediction of the change of water level at each point is possible.

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Deposition and Sedimentology of the Marine and Nonmarine Sedimentary Rocks of the Pyung-Ahn Group, Kangweondo, Korea (한국 고생대 후기의 평안층군 퇴적암(해성기원 및 육성기원)에 관한 퇴적작용과 퇴적환경 연구)

  • 박용안;최강원;김진호
    • The Korean Journal of Quaternary Research
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    • v.3 no.1
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    • pp.69-85
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    • 1989
  • The depositional environments of the Pyung-Ahn Group sedimentary rocks, Jeongseon-Kun, Kangweondo, Korea are investigated. The environments are understood to be characteristic transitional from a typical shallow marine to a typical continental environment. Such transitional conditions are also understood in various parts of Quaternary and modern environment on the earth. In particular, the absence of detrital feldspar sand grains in the Manhang and Keumcheon Formation Sandstone body is described firstly in Korea, and the fact and possible mechanism are discussed.

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