• Title/Summary/Keyword: Bansong Group

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A Review on the Stratigraphy, Depositional Period, and Basin Evolution of the Bansong Group (반송층군의 층서, 퇴적시기, 분지 진화에 관한 고찰)

  • Younggi Choi;Seung-Ik Park;Taejin Choi
    • Economic and Environmental Geology
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    • v.56 no.4
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    • pp.385-396
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    • 2023
  • The Mesozoic Bansong Group, distributed along the NE-SW thrust fault zone of the Okcheon Fold Belt in the Danyang-Yeongwol-Jeongseon areas, contains important information on the two Mosozoic orogenic cycles in the Koran Peninsula, the Permian-Triassic Songrim Orogeny and the Jurassic Daebo Orogeny. This study aims to review previous studies on the stratigraphy, depositional period, and basin evolution of the Bansong Group and to suggest future research directions. The perspective on the implication of the Bansong Group in the context of the tectonic evolution of the Korean Peninsula is largely divided into two points of view. The traditional view assumes that it was deposited as a product of the post-collisional Songrim Orogeny and then subsequently deformed by the Daebo Orogeny. This interpretation is based on the stratigraphic, paleontologic, and structural geologic research carried out in the Danyang Coalfield area. On the other hand, recent research regards the Bansong Group as a product of syn-orogenic sedimentation during the Daebo Orogeny. This alternative view is based on the zircon U-Pb ages of pyroclastic rocks distributed in the Yeongwol area and their structural position. However, both models cannot comprehensively explain the paleontological and geochronological data derived from Bansong Group sediments. This suggests the need for a new basin evolution model integrated from multidisciplinary data obtained through sedimentology, structural geology, geochronology, petrology, and geochemistry studies.

Structural Analysis of the Danyang Area, Danyang Coalfield, Korea (단양지역의 지질구조)

  • Kim, Jeong Hwan;Koh, Hee Jae
    • Economic and Environmental Geology
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    • v.25 no.1
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    • pp.61-72
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    • 1992
  • The Danyang area consists of the thrust and folded sedimentary rocks of Paleozoic and Mesozoic Era. The area is bounded by major tectonic units which are the Gagdong Thrust to the west and the Okdong Fault to the east. According to the structural analyses, the area is affected by polyphase deformation. This study establishes deformational sequence in the area. Mylonite zone along the Okdong Fault corresponds to the first generation of structures ($D_1$). $D_1$-structures are discrete shear zone in the Jangsan Formation and bedding parallel extensional deformation in the Cambro-Ordovician sequences. $D_2$-structures were formed prior to the sedimentation of the Jurassic Bansong Group, which are the NW-trending fold and linear structures. After sedimentation of the Bansong Group, the area is strongly affected by the Daebo Orogeny which produces NE-trending thrusts, folds and linear structures. Earlier structures were tightened and rotated toward NE. Some thrust faults did not propagate into the Bansong Group. It is suggested either the Bansong Group acted as a decoupling horizon or rest on unconformably on the thrust faults. The area is weakly affected by $D_4$-event of which structures are E-W trending folds and faults. The Jugryeong Fault clearly cut the earlier folds and thrust faults. The rocks within the fault zone were sliced and rotated during the strike-slip movements. Block rotation and transpressional features can be commonly observed.

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Effects of Project Activities Based on Multiple Intelligences to Elementary School Children's Science Achievement (다중지능에 기초한 프로젝트 활동이 초등학교 아동의 과학 학업성취도에 미치는 영향)

  • Lim, Chae-Seong;Wang, Kyung-Soon
    • Journal of The Korean Association For Science Education
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    • v.21 no.1
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    • pp.13-21
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    • 2001
  • This study examined the influences of project activities based on multiple intelligences to science achievement of elementary school children. The proportions of variance of science achievement explained by General Intelligence(GI) and Multiple Intelligences(MI) were analyzed, then the influences of project activities, which used various aspects of MI were investigated. Two classes of grade 5 at Pusan in Korea were selected for the study. On the basis of science achievement of prior term, the subjects were classified into upper-, average-, and lower-achievement groups. GI and MI were measured for each child, and the relationships of these measures with prior science achievement were analyzed using multiple regression analyses. In order to investigate the effects of the project activities on science achievement, the classes were divided into the control and experimental groups, which the former group learned science topics using the traditional teaching and learning method and the latter group performed the projects about the same topics using their own multiple intelligences. Then, their achievements were analyzed by ANOVA. Results showed that the proportion of variance explained by MI was higher about two times than that of explained by GI. Project activities contributed to the improvement of science achievement of average and upper achievers, however, in the case of under achievers, this effect was not statistically significant.

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Comparison of Time Management Behavior, Life Satisfaction between Gifted Middle School Students and General Students, and Relationship between the Time Management Behaviors and Life Satisfaction (중학교 영재학생과 일반학생의 시간관리 행동, 생활만족도 비교 및 시간관리 행동과 생활만족도의 관계)

  • Kim, Sun-Mi;Yoo, Mi-Hyun
    • Journal of Gifted/Talented Education
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    • v.23 no.3
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    • pp.315-333
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    • 2013
  • The purpose of this study was to compare the time management behaviors and life satisfaction of gifted students and general students, and to investigate relationships between the time management and the life satisfaction. For this study, 104 gifted middle school students and 203 regular middle school students in Kyunggi Province were participated. The results of this study were as follows.; First, there was significant difference in the time management behaviors between gifted students and general students. Analyzing by independent samples t-test showed that gifted students' time management behaviors showed significantly higher than that of general students'. There was no gender difference in gifted students' time management behaviors. However, there was a significant gender difference in general students. The interaction effect between the group and the gender did not appear. Second, there was significant difference in the life satisfaction between gifted students and general students. Analyzing by independent samples t-test showed that gifted students' life satisfaction showed significantly higher than that of general students'. There was no gender difference in both groups. The interaction effect between the group and the gender did not appear. Third, investigating the relationship between time management behaviors and life satisfaction of gifted students and general students, the results showed significantly positive correlations in both groups. Regression analysis was performed to investigate the impact of time management behaviors on life satisfaction, and it showed that time management behavior affects significantly on life satisfaction.

Geological Structures of the Yeongchun Area, Danyang Coalfield, Korea (단양탄전, 영춘지역의 지질구조)

  • Kim, Jeong Hwan;Lee, Je Yong;Nam, Kil Hyun
    • Economic and Environmental Geology
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    • v.25 no.2
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    • pp.179-190
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    • 1992
  • The Yeongchun area is located at the central part of the Danyang Coalfield, where Precambrian granitoids, Cambro-Ordovician Choseon Supergroup, Carboniferous-early Triassic Pyeongan Supergroup, middle Triassic-Jurassic Bansong Group and extrusive tuffs are exposed. The rocks in the area underwent four phases of deformation, which are (a) $D_1$ : Movement of the Okdong Fault, (b) $D_2$ : Formation of NW-SE trending folds and stretching lineations, (c) $D_3$: Movement of the Gagdong Thrust Fault and associated structures of NNE-SSW trending folds, and (d) $D_4$ : E-W trending strike-slip faults and folds. During the $D_3$-event, flexural slip deformation intensively affected rocks in the area. Strain measurements show relatively low strain intensity in the area. The types of strain ellipsoid are prolate in the hangingwall area and those near to the footwall area range from plane strain to weak oblate. The oblate type is developed in the region far from the footwall area.

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A Study on the Paleomagnetism of Southern Korea since Permian (페름기(紀) 이후(以後) 한국(韓國)의 고지자기(古地磁氣)에 관(關)한 연구(硏究))

  • Kim, Kwang Ho;Jeong, Bong II
    • Economic and Environmental Geology
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    • v.19 no.1
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    • pp.67-83
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    • 1986
  • Oriented hand samples were collected from Gobangsan Formation and Nogam Formation in the north of Danyang and south of Yeongchun, from Bansong Group in and around Danyang, from Nampo Group in Chungnam Coalfield, from Gyeongsang Supergroup distributed from Waegwan through Daegu to Gyeongsan and from Daegu to Goryong, and from volcanic flows in Jeongog area and Jeju Island to study the paleomagnetism of southern Korea since Permian. Stepwise alternating field and thermal demagnetization experiments were carried out to determine optimum fields and temperatures. Observed mean paleomagnetic directions are as follows: $D=331.5^{\circ}$, $I=25.1^{\circ}$, $a95=12.8^{\circ}$ for Permian, $D=325.6^{\circ}$, $I=46.1^{\circ}$, $a95=11.8^{\circ}$ for Triassic, $D=313.4^{\circ}$, $I=43.1^{\circ}$, $a95=16.0^{\circ}$ for early Jurassic, $D=41.3^{\circ}$, $I=64.6^{\circ}$, $a95=4.5^{\circ}$ for early Cretaceous, $D=28.3^{\circ}$, $I=58.1^{\circ}$, $a95=2.3^{\circ}$ for late Cretaceous, $D=2.0^{\circ}$, $I=55.8^{\circ}$, $a95=6.6^{\circ}$for Quaternary. To describe the tectonic translocation of southern Korean block, northern Eurasian continental block was used as a reference frame. For each age since Permian the expected northern Eurasian field directions in terms of paleolatitude and declination were calculated. The paleolatitudes of Permian ($13.2^{\circ}N$) and early Jurassic ($25.1^{\circ}N$) obtained from the study area are quite different from those of Permian ($66.0^{\circ}N$) and early Jurassic ($68.1^{\circ}N$) which are expected for northern Eurasia. The declinations of Permian ($331.5^{\circ}$) and early Jurassic ($313.4^{\circ}$) are also quite different from those of the Permian ($56.6^{\circ}$) and the early Jurassic ($47.5^{\circ}$) expected for northern Eurasia. The Cretaceous paleolatitude is similar to the expected within error limit, but the declination for the same period is significantly different from that of the expected for the northern Eurasia. From the above evidences it is suggested that the south Korean land mass had moved from low latitude in Permian to north and sutured to northern continental block since early Jurassic. The relative rotations of early Cretaceous($27.4^{\circ}$) and late Cretaceous($10.8^{\circ}$) to northern Eurasian continent reveal that the Korean land mass might be rotated clockwise in two different times, probably in late Early Cretaceous and in Tertiary.

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