• Title/Summary/Keyword: Dok Island

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Rosa laevigata Michx. (Rosaceae): A Newly Alien Plant in Korea

  • Lee, Woong;Kim, Jung-Hyun;Kim, Jin-Seok
    • Korean Journal of Plant Resources
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    • v.34 no.3
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    • pp.197-202
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    • 2021
  • We found Rosa laevigata Michx., a newly alien plant in Songjinpo-ri, Jangmok-myeon, Geoje-si, Gyeongsang nam-do. Rosa laevigata is native to China, Taiwan, and Vietnam. It is reported as a naturalized species in Japan, South Africa, United States, and the Pacific Islands. Rosa laevigata is distinguished from R. multiflora by the large size of its flower. Its Korean name is 'Wang-jjil-re-na-mu' based on the large flower. Here, we provide precise description, taxonomic key to Korean Rosa species, illustrations and photographs of its habit.

Sr, Nd and Pb isotopic investigations of ultramafic xenoliths and their host basalts from Jeju Island, Baekryeong Island, Boeun and Ganseong, Korea: Implications for a large-scale difference in the source mantle beneath East Asia

  • Park, Seong-Hee;Kwon, Sung-Tack;Hee Sagong;Cheong, Chang-Sik
    • Proceedings of the Mineralogical Society of Korea Conference
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    • 2001.06a
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    • pp.75-75
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    • 2001
  • We report Sr, Nd and Pb isotope data of clinopyroxene separates from ultramafic xenoliths and their host basaltic rocks in Jeju Island, Baekryeong Island, Boeun and Ganseong, Korea. The isotopic data of the xenoliths and host basalts are distinctly different from those of Korean basement rocks. Except for two xenoliths from Ganseong, all samples in this study have isotopic ratios within the combined range of MORB-OIB data. All basaltic rocks have Nd-Sr-Pb isotope compositions different from those of xenoliths, indicating that the host basaltic magma did not derive from the lithospheric mantle where the xenoliths originated. The range of isotopic composition of xenoliths is much greater than that observed in host basalts, which reflects small-scale heterogeneity of the lithospheric mantle. The greater isotopic heterogeneity of the lithospheric mantle probably reflects its long-term stability. The spinel peridotite xenolith data of Jeju Island, Baekryeong Island and Boeun display mixing hyperbolas between DMM and EM II end members. Since Jeju basalts have EM II-like isotopic signature, the mixing relationship shown by the isotopic data of the Jeju xenoliths can be interpreted as the result of infiltration of metasomatic fluid or melt derived from basaltic magma into DMM-like lithospheric mantle. In contrast to other xenolith sites, the Ganseong xenoliths are dominantly clinopyroxene megacryst and pyroxenite. Clinopyroxene megacrysts have different isotopic ratios from their host basalt, reflecting its exotic origin. Two Ganseong xenoliths (wherlite and clinopyroxenite) have much enriched Sr and Nd isotopic ratios and Nd model ages of 2.5-2.9 Ga, and plot in an array away from the MORB-OIB field. The mantle xenoliths from Korean Peninsula have similar $\^$87/Sr/$\^$86/Sr,$\^$143/Nd/$\^$144/Nd and $\^$207/Pb/$\^$204/Pb ratios to, but higher $\^$208/Pb/$\^$204/Pb ratios than, those from eastern China, indicating that Korean xenoliths are derived from the lithospheric mantle with higher Th/U ratio compared with Chinese ones. The isotopic data of xenolith-bearing basalts of Baekryeong Island and Ganseong, along with Ulreung and Dok Islands, show a mixing trend betlveen DMM and EM I in Sr-Nd-Pb isotopic correlation diagrams, which is also observed in tile northeastern Chinese basalts. However, the Jeju volcanic rocks show an EM II signature that is observed in southeastern Chinese basalts. The isotopic variations in volcanic rocks from the northern and southern portions of the East Asia reflect a large-scale isotopic heterogeneity in their source mantle.

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Mantle Source Lithologies of Late Cenozoic Basaltic Rocks and Two Varieties of Enriched Mantle in the Korean Peninsula (한반도 신생대 후기 현무암의 근원 맨틀 암상과 두 종류의 부화 맨틀)

  • Choi, Sung Hi
    • Korean Journal of Mineralogy and Petrology
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    • v.35 no.3
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    • pp.183-197
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    • 2022
  • Geochemical data, including Sr-Nd-Pb-Mg-Zn isotopes, reported on the late Cenozoic intraplate basaltic rocks in the Korean Peninsula (Mt. Baekdu, Jeongok, Baengnyeong Island, Pyeongtaek, Asan, Ganseong, Ulleung Island, Dok Island, and Jeju Island) are summarized to constrain their mantle source lithologies, and the nature of mantle end-members required. In the Sr-Nd isotope correlation diagram, Jeju basalts plot in the field of EM2-type oceanic island basalts (OIB), while the other basalts fall in the EM1-type OIB field. In Pb-Pb isotope space, Jeju basalts show a mixing array between Indian MORB and EM2 component, whereas the other basalts display an array with EM1 component. The Korean basalts were derived from a hybrid source of garnet lherzolite and recycled stagnant slab materials (eclogite/pyroxenite, pelagic sediments, carbonates) in the mantle transition zone. The EM1 component could be ancient (~2.0 Ga) K-hollandite-bearing pelagic sediments that were isolated for a long period in the mantle transition zone due to their neutral buoyancy. The EM2 component might have been relatively young (probably Pacific slab) and recently recycled clay-rich pelagic sediments. Eclogite and carbonates are unlikely to account for the EM components, but they are common in the mantle source of the Korean basalts.

Trichome morphology of Fallopia sect. Reynoutria (Polygonaceae) in Korea (한국산 닭의덩굴속 호장근절 (마디풀과) 식물의 털의 형태와 분류)

  • Moon, Hye-Kyoung;Park, Jin Hee;Park, Chong-Wook
    • Korean Journal of Plant Taxonomy
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    • v.41 no.1
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    • pp.51-57
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    • 2011
  • The microstructure of the leaf epidermis and trichomes of Fallopia sect. Reynoutria are examined using scanning electron microscopy. Fallopia sachalinensis was distinguished from other taxa in this section by its prominent epicuticular wax layer consisting of protruding wax rodlets. In addition, epicuticular rodlets of F. sachalinensis individuals from Ullung Island and Dok Island appear to be thinner than those from other regions, including Japan and Sakhalin. The stomatal size appears to be related to the ploidy level in the sect. Reynoutria, as the hexaploids, octoploids and dodecaploids tend to have larger stomata as compared to tetraploids. Three basic types of trichomes were found in the section; (1) conical unicellular trichomes, (2) uniseriate filiform trichome consisting of 1-8 cells, and (3) peltate glandular trichomes. The trichome types and their distribution appear to be useful in distinguishing the taxa in the section.

Taxonomical Review of the Korean Labroidei (Teleostei: Perciformes) (한국산 놀래기과 어류의 분류학적 검토)

  • Kim, Byung-Jik
    • Korean Journal of Ichthyology
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    • v.21 no.sup1
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    • pp.74-74
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    • 2009
  • The perciform suborder Labroidei comprising six families (Cichlidae, Embiotocidae, Pomacentridae, Labridae, Odacidae, and Scaridae) are characterized by having the specialized pharyngeal jaws for food processing, i.e., united fifth ceratobranchials and upper pharyngeal jaw articulating with the basicranium via diarthroses (Stiassny and Jensen, 1987). They usually inhabit in the most tropical and subtropical seas and comprise about 235 genera and roughly 2,274 species worldwide (Nelson, 2006). Concerning the Korean labroid fishes, Mori (1952) had listed 18 genera and 26 species belong to four families in his check list of Korean fishes since Jordan and Metz (1913) firstly reported six genera and seven species in only two families (Embiotocidae and Labridae). Chyung (1977) added two species, Tilapia mossambica and Cirrhilabrus temmincki, to Mori’s list and also classified them into three suborders, i.e., Embiotocina (containing only Embiotocidae), Pomacentrina (Cichlidae and Pomacentridae), and Labrina (Labridae and Scaridae). Subsequently, Lee and Kim (1996) reviewed the Korean labroidfishes taxonomically resulting in 22 genera and 32 species in five families with some taxonomical modifications including a new Korean record. It is remarkable to be added many new Korean recordsto the pomacentrids or the labrids for recent 10 years (Koh et al., 1995; Yoo et al., 1995; Koh et al., 1997; Myoung, 1997; Choi and Kim, 2000; Choi et al., 2002; Kim and Go, 2003). Recently, Kim et al. (2005) briefly described all members of the Korean Labroidei with a color photograph or a figure, recognizing 27 genera and 42 species in five families. In the present study, the current taxonomical status of the Korean labroid fishes including distributional features is summarized based both on specimens collected from the Korean waters and on literature survey to provide bio-information of the Korean native fish species. As a result, the Korean labroid fishes totally consist of 27 genera and 44 species in five families, that is, Cichlidae (1 species), Embiotocidae (3), Pomacentridae (15), Labridae (22), and Scaridae (2). They distributed mainly in the coastal waters of the South Sea, Korea, however, most pomacentrids or labrids occur in the coastal waters of Jeju Island only, although some species were observed in their larval or juvenile stages only from coastal waters of the island. Interestingly, several species are expanding their distribution north to Ulreung and Dok islands in the East Sea, Korea lately.

Eruption Cycles and Volcanic Form of the Dokdo Volcano, Korea (독도 화산의 분출윤회와 화산형태)

  • 황상구;전영권
    • Economic and Environmental Geology
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    • v.36 no.6
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    • pp.527-536
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    • 2003
  • The Dokdo volcano in the south-central part of the East Sea is classified into 8 rock units. The units and sequence suggest that the Dok Island forms a small stratovolcano constructed from at least 3 times eruption cycles above the sea level and proceeded with transformation of a few different eruption styles during each cycle. Reconstruction of the volcanic form, from the geologic structures and spatial lithofacies changes, suggests that the island is remnants of the southwestern caldera rim of the stratovolcano whose central part lies several hundred meters to the northeast. The subaqueous volcano shows abig guyot, which looks like a shield volcano, that represents gentle slope at 90-175 m deep and relatively steep one in 200∼2,000m, and 25∼30km wise base on sea floor. Therefore the total Dokdo volcano represents a multiple volcano that stratovolcano with small caldera overlies the big guyot.

Fungal Clusters and Their Uniqueness in Geographically Segregated Wetlands: A Step Forward to Marsh Conservation for a Wealth of Future Fungal Resources

  • Park, Jong Myong;Hong, Ji Won;Lee, Woong;Lee, Byoung-Hee;You, Young-Hyun
    • Mycobiology
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    • v.48 no.5
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    • pp.351-363
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    • 2020
  • Here, we investigated fungal microbiota in the understory root layer of representative well-conserved geographically segregated natural wetlands in the Korean Peninsula. We obtained 574,143 quality fungal sequences in total from soil samples in three wetlands, which were classified into 563 operational taxonomic units (OTU), 5 phyla, 84 genera. Soil texture, total nitrogen, organic carbon, pH, and electrical conductivity of soil were variable between geographical sites. We found significant differences in fungal phyla distribution and ratio, as well as genera variation and richness between the wetlands. Diversity was greater in the Jangdo islands wetland than in the other sites (Chao richness/Shannon/Simpson's for wetland of the Jangdo islands: 283/6.45/0.97 > wetland of the Mt. Gariwang primeval forest: 169/1.17/0.22 > wetland of the Hanbando geology: 145/4.85/0.91), and this variance corresponded to the confirmed number of fungal genera or OTUs (wetlands of Jangdo islands: 42/283> of Mt. Gariwang primeval forest: 32/169> of the Hanbando geology: 25/145). To assess the uniqueness of the understory root layer fungus taxa, we analyzed fungal genera distribution. We found that the percentage of fungal genera common to two or three wetland sites was relatively low at 32.3%, while fungal genera unique to each wetland site was 67.7% of the total number of identified fungal species. The Jangdo island wetland had higher fungal diversity than did the other sites and showed the highest level of uniqueness among fungal genera (Is. Jangdo wetland: 34.5% > wetland of Mt. Gariwang primeval forest: 28.6% > wetland of the Hanbando geology: 16.7%).

Study of CO Oxidation on Bare and $TiO_2$-coated NiO/$Ni(OH)_2$

  • Nam, Jong-Won;Kim, Kwang-Dae;Kim, Dong-Wun;Seo, Hyun-OoK;Kim, Young-Dok;Lim, Dong-Chan
    • Proceedings of the Korean Vacuum Society Conference
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    • 2011.08a
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    • pp.109-109
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    • 2011
  • CO oxidaition reacitvity of bare and $TiO_2$ -coated NiO/$Ni(OH)_2$ nanoparticles was studied. For the deposition of $TiO_2$ atomic layer deposition was used, and formation of three-dimensional island of $TiO_2$ on NiO/$Ni(OH)_2$ could be identified. Based on the data of X-ray Photoelectron Spectroscopy, we suggest that only $Ni(OH)_2$ existed on the surface, whereas NiO disappeared upon $TiO_2$ deposition. Both CO adsorption and CO oxidation took place on NiO/$Ni(OH)_2$ surfaces under our experimental conditions. CO adsorption was completely suppressed after $TiO_2$ deposition, whereas CO oxidation activity was maintained to large extent. It is proposed that bare NiO can uptake CO under our experimental condition, whereas hydroxylated surface of NiO can be active for CO oxidation.

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Distribution, Characterization, and Diversity of the Endophytic Fungal Communities on Korean Seacoasts Showing Contrasting Geographic Conditions

  • You, Young-Hyun;Park, Jong Myong;Seo, Yeong Gyo;Lee, Woong;Kang, Myung-Suk;Kim, Jong-Guk
    • Mycobiology
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    • v.45 no.3
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    • pp.150-159
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    • 2017
  • This study analyzed the distribution of endophytic fungi in 3 coastal environments with different climatic, geographical, and geological characteristics: the volcanic islands of Dokdo, the East Sea, and the West Sea of Korea. The isolated fungal endophytes were characterized and analyzed with respect to the characteristics of their host environments. For this purpose, we selected common native coastal halophyte communities from three regions. Molecular identification of the fungal endophytes showed clear differences among the sampling sites and halophyte host species. Isolates were also characterized by growth at specific salinities or pH gradients, with reference to previous geographical, geological, and climate studies. Unlike the East Sea or West Sea isolates, some Dokdo Islands isolates showed endurable traits with growth in high salinity, and many showed growth under extremely alkaline conditions. A smaller proportion of West Sea coast isolates tolerate compared to the East Sea or Dokdo Islands isolates. These results suggest that these unique fungal biota developed through a close interaction between the host halophyte and their environment, even within the same halophyte species. Therefore, this study proposes the application of specific fungal resources for restoring sand dunes and salt-damaged agricultural lands and industrialization of halophytic plants.

A Study on Cho O-Ryun's Life and Thoughts of Physical Education (수영선수 조오련의 생애와 체육사상)

  • Jeong, Dong-Hee;Lee, Tae-Ung
    • Journal of Fisheries and Marine Sciences Education
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    • v.26 no.3
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    • pp.567-577
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    • 2014
  • The purpose of this research is to study in depth about the life, activities, and achievements of the swimming gold medalist in Asian Game, Cho O-Ryun, to make systematic correction. This research mainly used literary data to try making theoretical contemplation, and to raise objectivity and substantiality of literary research, and to be devoted to limited literary contents, it used acquaintances who are related to this research, especially his wife, Lee Sung-Lan. Cho O-Ryun's thoughts in physical education can be described as nationalistic physical educational thoughts. He did not only have pride as Korean, and tried to show superiority of our nation to the world, but he also tried very hard to prove that Dok-do Island is a Korean territory and not Japan's. He lived with water all his life, showed his everything as a proud Korean, worked as the most patriotic person of 20thcentury in Korea, and became to be a hero, dream, and hope to people in Korea. Spent all his sweat and energy to our country Korea, Cho O-Ryun, he was this era's true hero.