• Title/Summary/Keyword: 연대학

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Radiocarbon Dating Practices by Benzene Liquid Scintillation Method (벤젠-액체 섬광계수법에 의한 $^{14}C$ 연대측정)

  • Lee, Yeon-Gyu;Choi, Jeong-Min;Kim, Chang-Gyu
    • The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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    • v.4 no.3
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    • pp.180-187
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    • 1999
  • Radiocarbon dating method using benzene liquid scintillation was performed on the oyster shell fragments which producted from the shell mounts at Hadong Mogdori in Kyeongsangnamdo. This paper described to the age dating method and compared to the result. The carbon in sample is synthesized to a benzene through the sample preparation, $SrCO_3$, $SrC_2$, $C_2H_2$ and $C_6H_6$ synthesizing process. Age dating is calculated by Wallac 1415 Liquid Scintillation Counter. The result of age dating is estimated to be $4905{\pm}112$ yr BP in Yosu Univ. which is a good agreement with the result in Shimane Univ. ($4912{\pm}123$ yr BP). Radiocarbon dating method using benzene liquid scintillation is a simple and economical in operation and establishment, it has a potential instrumentation in the university and research institute.

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Study of the Last Volcanic Activity on Historical Records on Jeju Island, Korea (고문헌에 기록된 제주도 최후기 화산활동에 관한 연구)

  • Ahn, Ung San
    • The Journal of the Petrological Society of Korea
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    • v.25 no.1
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    • pp.69-83
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    • 2016
  • Radiocarbon and OSL ages of three monogenetic volcanoes inferred to be the last volcanoes on Jeju Island, Korea were determined to identify a volcano described in historical records. The results show that the ages of those volcanoes are roughly <3.8 ka (Songaksan), >4.5 ka (Biyangdo), and <6~7 ka (Ilchulbong). Though our efforts to make a positive match between historical records and volcano-chronological dating were not successful, we make a new suggestion in this paper that two historical records of volcanic activity in 1002 and 1007 A.D. could be interpreted to be the sequential volcanic events from a single monogenetic volcano. In addition, based on a volcanological reinterpretation of historical records, we infer that the volcano described therein is most likely Mt. Songaksan, in Daejeongeup, which had early phreatomagmatic and late magmatic activities after 3.8 ka ago. Furthermore, considering the geopolitical relationship between the Goryeo Dynasty and the Tamna Kingdom, in addition with the culture of the era, this study sheds new light on the possibility that there is a time gap between the actual eruptions and the historical recording of them by ancient people.

K-Ar ages of the hydrothermal clay deposits and the surrounding igneous rocks in southwest Korea (한국 남서부의 열수점토광상과 주변암에 대한 K-Ar 연대 측정)

  • Kim In Joon;Nagao Keisuke
    • The Journal of the Petrological Society of Korea
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    • v.1 no.1
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    • pp.58-70
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    • 1992
  • From the K-Ar age determinations for the clay deposits and their surrounded rocks in southwest Korea, the ages of the ore formation in all clay deposits fall in very narrow range from 78.1 to 81.4 Ma. K-Ar ages of clay deposits are slightly younger than those of the Cretaceous volcanic rocks (Hwangsan Formation, 81.4 to 86.4 Ma) and are slightly older than those of the Cretaceous granitic rocks (77.1 to 81.5 Ma). These results indicate that clay deposits were formed with genetical relation to late Cretaceous felsic magmatism. Weolgagsan granite, which has been previously considered to be Cretaceous, is proved to be formed its age in Jurassic (140.9 and 144.8 Ma). The close relationships of K-Ar ages between the clay deposits and Cretaceous granitic rocks suggest that the clay deposits were formed during the hydrothermal alterations caused by the thermal effects (hydrothermal circulation) of the granitic intrusions rather than by the hydrothermal activities associated with volcanic activities.

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