• Title/Summary/Keyword: 육성층

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Stratigraphy and Provenance of Non-marine Sediments in the Tertiary Cheju Basin (제주분지 제삼기 육성층의 층서 및 퇴적물 기원)

  • Kwon Young-In;Park Kwan-Soon;Yu Kang-Min;Son Jin-Dam
    • The Korean Journal of Petroleum Geology
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    • v.3 no.1 s.4
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    • pp.1-15
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    • 1995
  • Seismic reflection profiles and exploratory drilling well samples from the southern marginal-continental shelf basin of Korea delineate that the Tertiary sedimentary sequences can be grouped into five sequences (Sequence A, Sequence B, Sequence C, Sequence D and Sequence E, in descending order). Paleontologic data, K-Ar age datings, correlation with tuff layers and sequence stratigraphic analysis reveal that the sequences A, B, C, D and E can be considered as the deposits of Holocene $\~$ Pleistocene, Pliocene, Late Miocene, Early $\~$ Middle Miocene and Oligocene, respectively. The sequence stratigraphic and structural analyses suggest that the southern part of the Cheju Basin had experienced severe folding and faulting. NE-SW trending strike-slip movement is responsible for the deformation. The sinistral movement of strike-slip fault ceased before the deposition of Sequence B. Age dating and rare-earth elements analysis of volvanic rocks reveal+ that the Sequence D was deposited during the Early $\~$ Middle Miocene and the Sequence I was deposited earlier than the deposition of the Green Tuff Formation. Sedimentary petrological studies indicate that sediments of the Sequence I came from the continental block provenance. After the deposition of the Sequence E, uplift of the source area resulted in increase of sediment supply, subsidence and volcanic activities. The Sequence D show these factors and the sediments of the Sequence D are considered to be transported from the recycled orogenic belt.

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Sea Level Change during the Middle Holocene at Bibong-ri, Changnyeong-gun, Gyeongsangnam-do, South Korea (창녕 비봉리 지역의 Holocene 중기 해수면변동)

  • Hwang, Sangill;Kim, Jeong-Yun;Yoon, Soon-Ock
    • Journal of the Korean Geographical Society
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    • v.48 no.6
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    • pp.837-855
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    • 2013
  • The remains and relics such as wood vessel, shell middens and acorn hollows related to marine environments were excavated at Bibong-ri, Changnyeong-gun, Gyeongsangnam-do, South Korea, approximately 70km apart from the Nakdong River mouth. The sea-level changes were reconstructed based on characteristics of shell middens and acorn hollows, sedimentary facies, AMS dating, and diatom analysis. The shell middens and acorn hollows were constructed during the early Neolithic Age and provide information on the paleo-sea level, because of influences of marine processes. The sedimentary facies are classified into a bedrock, base gravel and Holocene sediment (marine, terrestrial and back marsh sediments), upward. The sea level fluctuated during the middle Holocene is in harmony with those in Sejuk-ri, Ulsan and Pyeongtaek. In particular, the sea level at Bibong-ri of study area was higher than the mean high tidal level in Gimhae by approximately 1m during 5,000yr BP and maintained the stable condition during 4,000yr BP.

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Ancient Ox-bow Lake Deposits Hoedong-ri Jeongseon-gun Gangweondo (고생대 우각호의 퇴적층 강원도 정선군 회동리)

  • 박용안
    • The Korean Journal of Quaternary Research
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    • v.8 no.1
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    • pp.23-32
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    • 1994
  • 고생대(폐름기)의 육성 퇴적층(옥갑산층) 일부분이 고기 우각호(ox-bow lake)에 서 퇴적된 것으로 해석된다, 옥갑산층의 하부층서의 일부분은 암회색 이암/담회색 사암의 호층 단위가 평균 5.1cm 두께로 약 80회반복하는 암상을 나타낸다. 이 암상의 퇴적환경은 층서적 상하 암상의 연합에 근거하면 해안 평야로서 하천 범람원 분지의 쇄설성 퇴적환경의 일부이 면서 사행천과 연관된 우각호 퇴적환경으로 해석된다.

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Intermediate Culture of the Scallop, Patinopecten yessoensis in the East Coast of Korea (동해안 참가리비, Patinopecten yessoensis의 중간육성)

  • Park, Young-Je;Rho, Sum;Lee, Jeong-Yong
    • Journal of Aquaculture
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    • v.13 no.4
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    • pp.339-351
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    • 2000
  • Optimal environmental conditions, that sustained fastest growth, lowest mortality and abnormality of the scallop Patinopecten yessoensis, were identified from field experiments undertaken at Chumunjin during 1991-1998. Temperature within the water column 10~30 m depth ranged between 5 and 23$^{\circ}C$; high temperature and daily fluctuation resulted in growth retardation and heavy mortality of the scallop. Optimal salinity range was between 31.5 and 34.5%0 and water transparency 6.0 and 18.1 m, which was significantly affected by phytoplankton density. Chlorophyll concentration ranged between 0.04 and 3.51 f.lgfL. Low temperature and high chlorophyll concentration appear to support faster growth of the scallop. Optimal periods of transplantation for intermediate culture were between mid July and early November: cultured under high density during July-August as a first step and under low density during mid September through early November as a second step. Optimal stocking density in square net cage (<35${\times}$35 em) for intermediate culture was 30-40 individuals per cage for main culture using lantern net and 80 -100 individuals of the size of 1.5 ~ 3.0 em shell height per cage for sowing culture. During the intermediate culture, the highest growth was realized, when the cage was held at water depth between 10 and 15 m. Water depth below 25 m, however, was best to avoid mass mortality during the periods of abnormally high water temperature and high variation of water temperature. The daily growth rate during the intermediate culture was between 0.019~0.381 mm; low in January and February but high in March and April. It is suggested that the main culture is commenced before June under low stocking density to avoid the possibility of mass mortality during summer by high water temperature.

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