• Title/Summary/Keyword: 기원지

Search Result 533, Processing Time 0.032 seconds

Astrophysical Origin of Cosmic Magnetism

  • Jo, Jeong-Yeon
    • The Bulletin of The Korean Astronomical Society
    • /
    • v.38 no.1
    • /
    • pp.41.1-41.1
    • /
    • 2013
  • 우주 자기장의 기원은 잘 알려져 있지 않다. 크게 나누어서 우주론적인 기원과 천문학적인 기원을 고려할 수 있다. 자기장의 기원이 무엇이든지 간에, 난류는 씨앗자기장을 증폭시키는데 큰 역할을 한다. 본 발표에서는 천문학적인 기원을 가지는 씨앗자기장이 난류 내에서 어떻게 성장하는 지를 논의한다. 또한 과연 관측을 통해서 천문학적 기원과 우주론적 기원을 구분할 수 있는 지를 논의한다.

  • PDF

A Review on the Depositional Age and Provenance of the Taean Formation in the Western Gyeonggi Massif (서부 경기육괴에 분포하는 태안층의 퇴적시기와 기원지에 대한 고찰)

  • Choi, Taejin;Park, Seung-Ik
    • Economic and Environmental Geology
    • /
    • v.52 no.5
    • /
    • pp.347-356
    • /
    • 2019
  • Various studies regarding the sedimentary environment, depositional age, provenance, and metamorphic history have been carried out on the Taean Formation in the western part of Gyeonggi Massif, since the unique detrital zircon age pattern was revealed. This review paper introduces the previous researches on the Taean Formation and discusses the depositional age and provenance. The Taean Formation was traditionally regarded as a Precambrian stratigraphic unit, but recently it is interpreted to be a middle or upper Paleozoic formation due to the occurrence of large amounts of Early to Middle Paleozoic detrital zircons. The Taean Formation consists of metasandstone, argillaceous schist, and phyllite which are mainly made up of quartz and mica. The protoliths are interpreted as turbidites deposited in deep sea fan environment. The Taean Formation has been interpreted to be deposited between the Devonian to Triassic ages given the age differences between detrital zircons and intrusive rocks. There are two opinions that the deposition age is close to the Devonian or the Permian period. The provenance of this formation is supposed to be South China block, Chinese collisional belt, or Gyeonggi Massif. Given the available detrital zircon ages of the Taean Formation and other Korean (meta)sedimentary rocks, the Taean Formation shares major source rocks with Yeoncheon Group and Pibanryeong Unit of the Okcheon Supergroup, but their source regions are not entirely consistent. Considering the existing hypotheses about the depositional timing and provenance, we put weight on the possibility that the Taean Formation was deposited between Permian and Early Triassic periods. However, further studies on the stratigraphy and sedimentary petrology are needed to clarify its definition and to elucidate the provenance.

Estimation of te origin through Disposable Lighters Monitoring of the nakdong River Esturary Using GIS (GIS을 활용한 낙동강 하구 해안의 일회용라이터 모니터링을 통한 발생지 추정)

  • Kim, Young-Min;Jang, Seon-Woong;Yoon, Hong-Joo
    • The Journal of the Korea institute of electronic communication sciences
    • /
    • v.10 no.6
    • /
    • pp.729-736
    • /
    • 2015
  • In this study, It was analyzed to estimate the origin from the collected disposable lighters with the printed company name and telephone number on the surface. Monitoring was done bimonthly from 2 areas of sandbar Coastline of Nakdong River Estuary(Jinu-do, Shinja-do) and 3 areas(Doomo beach, Heungnam beach, Yeocha beach) of Northeastern coast of Geoje-do. As a result of the monitoring, there were 166 lighters collected. Then, the monthly occurrence amount was concentrated in Jun, August. The origin of Disposable lighters that flowed in study area were mostly cause to the Nakdong River basin region and the coastal area where population densities are high.

Preliminary Results from Sandstone Petrography of the Icheonri Formation in Gijang-gun, Busan: Implications for Provenance and Tectonic Setting (부산 기장군에 분포하는 백악기 이천리층 사암 조성의 예비 연구: 기원지와 조구조 역사 해석에의 의의)

  • Young Ji Joo;Heeseon Yang;Kyeongtae Kim;Hyun Ju Kim
    • Journal of the Korean earth science society
    • /
    • v.44 no.2
    • /
    • pp.161-168
    • /
    • 2023
  • While numerous previous studies investigated the provenance and tectonic history of the Gyeongsang Supergroup, less are known about other Cretaceous strata in South Korea. This study presents preliminary results from petrographic analysis of the Cretaceous Icheonri Formation distributed in Gijang-gun, Busan. Based on the immature texture and composition of the Icheonri sediments, we interpret that they were derived from weakly denudated Cretaceous arc volcanoes developed along the eastern margin of the Asian continent, with limited weathering and transport. Additionally, the presence of chrome spinel grains in the sediments suggests the existence of ultramafic bodies exposed in their provenance. Further studies will advance our understanding of the tectonic developments in the southeastern Gyeongsang Basin, and facilitate a comprehensive correlation between the Icheonri Formation and the Gyeongsang Supergroup.

Characteristics and Provenance of Heavy Minerals in the Yellow Sea and Northern East China Sea (황해 및 동중국해 북부의 중광물 특성과 기원)

  • Koo, Hyo Jin;Lee, Bu Yeong;Cho, Hyen Goo
    • Economic and Environmental Geology
    • /
    • v.53 no.5
    • /
    • pp.505-515
    • /
    • 2020
  • The Yellow Sea and northern East China Sea contain a transgressive sand layer. Numerous sedimentary studies have been carried out in these sand deposits using seismic exploration and core sediment techniques, but few mineralogical studies have been reported. The major purposes of this study are to describe the distributions of heavy minerals throughout the Yellow sea and northern East China Sea and to identify the provenance of coarse sediments using the mineral chemistry. Eight heavy mineral species were identified in the study area (epidote, amphibole, garnet, zircon, sphene, rutile, apatite, and monazite). The study region was divided into six areas (areas A to F) based on heavy mineral distributions and sampling locations. In mineral chemistry, the amphiboles present are classified as edenite and hornblende in the calcic amphibole group, and the garnets are identified primarily as almandine in the pyralspite group. A combined data set of heavy mineral distributions and mineral chemistry showed clear differentiation of the characteristics of the six classified areas, enabling determination of provenance and sedimentary environment. Area A and B in the eastern Yellow Sea were originated from the Korean peninsula, and these regions showed different heavy mineral characteristics by tidal current and coastal current. In addition, monazite was only found in the area B and could be used as an indicator from the southwestern Korean peninsula. Area D and E in the western Yellow Sea showed the characteristics of sediments originating from the Huanghe, and sediment in the area E was derived from the Changjiang. Area C in the northern East China Sea appeared to have Changjiang-origin sediment, and abundant apatite indicated that area C was formed close to the Last Glacial Maximum.

Reconstruction of the Origin of the Gudle (구들의 기원지(起源地) 재고(再考))

  • Oh, Seunghwan
    • Korean Journal of Heritage: History & Science
    • /
    • v.54 no.1
    • /
    • pp.100-119
    • /
    • 2021
  • This paper has been written to verify the existing theory that districts occurred independently in various parts of the world, including the Korean Peninsula. Song Giho (2006) claims that the origin of the Gudle, is an example of polygenism that occurred in various areas in the world, including the Korean peninsula. This argument has been corroborated by a large number of researchers. However, it is difficult to understand the lineage of Gudle and its process of development, if a theory of polygenism is continued to be taken into account. The place which is targetet by this theory is the North-West area of the Korean peninsula, south of Primorsky Krai, and in the northern area of Zabaikal-Mongolia. This means that these areas developed independently because they were far from each other and had no direct cultural relationship. However, the structure of Gudle, shape, and assemblages of earthenware it cannot be explained by polygenism, as they are the same in every place. Furthermore, it is also questionable as to the timing and region of emergence of the culture in East Asia over a limited time frame of 3-2 BC. Gudle are formed by furnaces with roofs and walls, Gorae, which saves heat, and it has smoke ventilation that draws smoke out. Therefore, the Gudle is not a structure that anyone can make without advanced technical understanding. So far, the only facility with furnaces and smoke ventilation that appear before the Gudle is Buttumak. Thus, the Gudle is likely to have been invented in the place where Buttumak were used. The area as known for the origin of Gudle was observed to verify the existence of the Buttumak's structure, but none of these facilities were found. The Gudle suddenly appeared within a new culture that had never existed before. That means that none of the three places had the conditions under which the Gudle could be invented, so it must have been introduced from outside. In conclusion, the three places that I mentioned above are not the origin of Gudle. So, the origin of Gudle has to be found elsewhere.

Provenance Study of 99MAP-P63 Core Sediments in the East China Sea (동중국해 99MAP-P63 코어 퇴적물의 기원지 연구)

  • Choi, Jae Yeong;Koo, Hyo Jin;Cho, Hyen Goo
    • Journal of the Mineralogical Society of Korea
    • /
    • v.31 no.4
    • /
    • pp.257-266
    • /
    • 2018
  • East China Sea (ECS) is known to be supplied with large amounts of sediments form Huanghe, Changjiang and various rivers in Korea. Many studies have been conducted to identify the effects of rivers and deposition process of ECS, but no consensus has been reached. In this study, clay minerals, rare earth elements (REEs) and grain size were analyzed to study the provenance and sedimentation environment of core 99MAP-P63 in ECS. Clay mineral contents of 99MAP-P63 are abundant in order of illite, chlorite, kaolinite, and smectite. The provenance of 99MAP-P63 sediments using clay minerals is interpreted as the Changjiang regardless of depth. As a result of REEs analysis, 99MAP-P63 sediments are very similar to Chinese rivers sediments. Therefore, the provenance of 99MAP-P63 is Changjiang, and the influence of Korean river seems to be insignificant. 99MAP-P63 sediments are generally classified as sandy silt, but the top of the core is divided into sand with a sand contents of 85 %. Compared with surrounding cores, sandy silt sediments arecorresponded to the low stand stage when sea-level was low, and the sediments were thought to have been supplied directly through the paleo-Changjiang. Sandy sediments in uppermost of core are corresponded to transgressive stage. Although distance from estuary was increased due to sea-level rise, it was possible to supply coarse sediments due to high bottom stress, and the paleo-Changjiang sediments deposited in study area were re-deposited.

Properties and Provenance of Loess-paleosol Sequence at the Daebo Granite Area of Buan, Jeonbuk Province, South Korea (전북 부안 화강암지역 뢰스-고토양 연속층의 퇴적물 특성과 기원지)

  • Park, Chung-Sun;Hwang, Sang-Ill;Yoon, Soon-Ock
    • Journal of the Korean Geographical Society
    • /
    • v.42 no.6
    • /
    • pp.898-913
    • /
    • 2007
  • We examined soil properties and provenance of loess-paleosol sequences at the Daebo Granite area of Buan, Jeonbuk Province, South Korea. The section consists of the surface layer, Layer 1(paleosol), Layer 2(loess), Layer 3(paleosol), Layer 4(loess), and Layer 5(paleosol), from top to bottom and thickness of the exposed section is approximately 280cm. The magnetic susceptibility values show the distinct variations between the loess- and the paleosol layer. Even though pH, ORP, water content, and soil hardness do not display the obvious differences in the section, the organic content indicates the variation similar to those of the magnetic susceptibility. In the respect of the soil colors measured under 3 conditions, although the variations of the wet soil color exceedingly reflect the difference of the layers, these variations are obscure in some points in the section due to the characteristics of the Munsell color system. Based on the geomorphological properties, sedimentary structure, the difference of the major element composition and the condrite-normalized rare earth element(REE) patterns showing the clear difference from the adjacent bedrocks and stream sediments and the similarity to those of the Chinese Loess Plateau, it is suggested that the section was formed by the material originated from the Chinese Loess Plateau and peripheral areas. However, because the material experienced the alteration after sedimentation under the environment of the sediment area, it has the properties different from the material in the provenance areas. This phenomenon may result in the climatic condition of Korea, especially in precipitation.

Distribution Pattern, Geochemical Composition, and Provenance of the Huksan Mud Belt Sediments in the Southeastern Yellow Sea (황해 남동부 흑산니질대 퇴적물의 분포, 지화학적 조성 및 퇴적물 기원지)

  • Ha, Hun Jun;Chun, Seung Soo;Chang, Tae Soo
    • Journal of the Korean earth science society
    • /
    • v.34 no.4
    • /
    • pp.289-302
    • /
    • 2013
  • In order to determine the provenance of the Huksan Mud Belt sediments in the southeastern Yellow Sea, the major and rare earth elements of the same sediments were analyzed. The surface sediments were sampled from top of piston-cores and box-cores taken at 51 sites within the Huksan Mud Belt. With the mean grain size of $5-6{\phi}$, the sediments of the study area are mud-dominated. The spatial distribution patterns show that silt content is high in the northern Mud Belt, whereas clay content increases as it moves toward the southern Mud Belt. Interestingly, the geochemical compositions both of major and rare earth elements have resulted in differences of sediment provenance. Among the major elements, plots of Fe/Al vs. Mg/Al ratios, $Al_2O_3$ vs. MgO ratios, and $Al_2O_3$ vs. $K_2O$ reveal that the Huksan Mud Belt sediments are dominated by the Korean river-derived sediments. However, the characteristics of rare earth elements infer sediments originating from the Chinese rivers. This discrepancy between the above provenances is attributed to the different contributory factors in the content of chemical elements. Considering strong correlation between major elements with grain sizes, the contents of the major elements are thought to be influenced by the grain size. However, there is a weak correlation between rare earth elements and grain sizes. The behaviour of rare earth elements may be controlled by heavy minerals, rather than grain sizes. Further study requires to solve the discrepancy arose from the difference in applied chemical tracers.