• Title/Summary/Keyword: Baegryeong Island

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Geochemical Characteristics of Clinopyroxenes in the Upper Mantle Rocks under the Baegryeong Island and the Boeun (백령도와 보은 지역의 상부맨틀암석 내의 단사휘석의 지화학적 특징)

  • Kil Young Woo;Lee Seok Hoon
    • Journal of the Mineralogical Society of Korea
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    • v.18 no.1
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    • pp.61-72
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    • 2005
  • Modal and chemical compositions of clinopyroxnes in spinel peridotites from the Baegryeong Island and the Boeun, enclosed in Miocene alkali basalt, are important for understanding the pre-eruptive temperature condition and chemical processes such as mantle depletion and enrichment. All spinel peridotites show transitional texture between protogranular and porphyroclastic textures. Temperature ranges of spinel peridotites from the Baegryeong Island and the Boeun at 15 kb are 773∼1188℃ and 705∼1106℃, respectively. The spinel peridotites from the Baegryeong Island and the Boeun have undergone the 1∼10% and 1∼4% fractional melting, which were determined by using primitive mantle-normalized Y and Yb of clinopyroxenes. LREE enrichment patterns of clinopyroxene indicate that these rocks from both areas have undergone cryptic mantle metasomatism without new minerals.

Late Quaternary Sedimentation in the Yellow Sea off Baegryeong Island, Korea (한국 황해 백령도 주변해역 후 제4기 퇴적작용)

  • Cho, MinHee;Lee, Eunil;You, HakYoel;Kang, Nyen-Gun;Yoo, Dong-Geun
    • Geophysics and Geophysical Exploration
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    • v.16 no.3
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    • pp.145-153
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    • 2013
  • High-resolution chirp profiles were analyzed to investigate the echo types of near-surface sediments in the Yellow Sea off the Baegryeong Island. On the basis of seafloor morphology and subbottom echo characters, 7 echo types were identified. Flat seafloor with no internal reflectors or moderately to well-developed subbottom reflectors (echo type 1-1 and 1-2) is mainly distributed in the southern part of the study area. Flat seafloor with superposed wavy bedforms (echo type 1-3) is also distributed in the middle part. Mounded seafloor with either smooth surface or superposed bedforms (echo type 2-1, 2-2, and 2-3) occurs in the middle part of the study area. Irregular and eroded seafloor with no subbottom reflectors (echo type 3-1) is present in the northern part of the study area off the Baegryeong Island. According to the distribution pattern and sedimentary facies of echo types, depositional environments can be divided into three distinctive areas: (1) active erosional zone due to strong tidal currents in the northern part; (2) formation of tidal sand ridges in response to tidal currents associated with sea-level rise distributed in the middle part; and (3) transgressive sand sheets in the southern part. Such a depositional pattern, including 7 echo types, in this area reflects depositional process related to the sea-level rise and strong tidal currents during the Holocene transgression.

BIOLOGICAL STUDIES ON THE SAND-EEL, AMMODYTES PERSONATUS GIRARD (까나리, Ammedytes Personatus GIRARD의 생물학적 연구)

  • CHUN Chan-Il
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.7 no.4
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    • pp.215-220
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    • 1974
  • The sand-eel, Ammedytes Personatus is a commercially important fish abounantly found in west and east coast of Korea. Samples were collected from the Baegryeong Island (Yellow Sea), Geoje Island(southern coast) and Jumunjin (East Sea) from May 1973 to December 1974. In this paper the author dealt with some biological point of the fish, especially the relationship between total length ang body weight, and the major spawning season and sex ratio. 1. The major spawning season was confined to the end of November and the end of December at Jumunjin. 2. The sex ratio (male/female) is 0.75 before the main spawning season and increases up to 1.36 after spawning at Jumunjin in 1974. 3. The relationship between the total length (L) and body weight (In were represented as follows: $W=0.0001906L^{3.1998319}$ for the sample from Baegryeong Is. $W=0.0003419L^{3.0213438}$ for the sample from Geoje Is. $W=0.0002655L^{3.1408629}$ for the sample from Jumunjin.

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Variation in the Vertebral Number of Sand-eel, Ammodytes personatus GIRARD (까나리의 생물학적 기초조사)

  • 전찬일
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.15 no.1
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    • pp.1-3
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    • 1979
  • The sand-eel, Ammodytes personatus GIRARD, "Kka-na-ri" is an important commercial fish inhabiting the coastal waters of Korea. The numbers of vertebrae (except urostyle) waR statistically analysezed based on the samples collected at three major fishing localitie" Jumunjin (East Sea), Geoje Island (southern coast) and Baegryeong Island (Yellow Sea) from May 1978 to June 1979. It was found that there was a very distinct difference in the numbers of vertebrae in the samples.rae in the samples.

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