Depositional processes of mass flows beyond the base-of-slope area and changes in slope failures in the SW Ulleung Basin (East Sea, Korea)
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Title
- Depositional processes of mass flows beyond the base-of-slope area and changes in slope failures in the SW Ulleung Basin (East Sea, Korea)
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Author(s)
- 이상훈; 정우열; Gardner, J.M.; 강동진
- KIOST Author(s)
- Lee, Sang Hoon(이상훈); Kang, Dong Jin(강동진)
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Alternative Author(s)
- 이상훈; 강동진
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Publication Year
- 2012-05-01
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Abstract
- 17 AMS 14C ages reveals spatial and temporal variations in depositional style of mass-flow lobes in the Ulleung Basin. On MR1 sonar image, eight NS elongated mass-flow lobes are identified in the western basin plain (>2100 m). Lobes 14, deposited retrogressively, have large dimensions (>27 km long and 1525 km wide) and occupy in the lower stratigraphic position. On the other hand, lobes 58, deposited in the more proximal area,have small dimensions (8.831.5 km long and 1.212 km wide) and occur in the upper stratigraphic position. Lobes 1 and 2 are characterized by relatively strong back-scattering intensity with smooth surfaces on MR1 image,and show flat, sharp bottom echo and several distinct to diffuse internal reflectors in chirp profiles. Sediments near their edges consist of fine-grained (muddy) turbidites with minor massive clay-rich sand. However, they change to coarse-grained debrites and turbidites with the overlying fine-grained turbidites toward the proximal part. Lobes 1 and 2 deposited between ca. 20 and 18 cal. ka B.P. Lobes 3 and 4, overlying lobe 2, show weak to medium back-scattering intensity on MR1 image with slightly irregular to hummocky surfaces corresponding to small-scale (<100 m wide and <5 m high) hyperbolic bottom echoes in chirp profiles. Upper surfaces of the lobes are nearly flat to convex-up in cross Lobes 14, deposited retrogressively, have large dimensions (>27 km long and 1525 km wide) and occupy in the lower stratigraphic position. On the other hand, lobes 58, deposited in the more proximal area,have small dimensions (8.831.5 km long and 1.212 km wide) and occur in the upper stratigraphic position. Lobes 1 and 2 are characterized by relatively strong back-scattering intensity with smooth surfaces on MR1 image,and show flat, sharp bottom echo and several distinct to diffuse internal refl
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URI
- https://sciwatch.kiost.ac.kr/handle/2020.kiost/27825
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Bibliographic Citation
- EGU, pp.3879, 2012
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Publisher
- EGU
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Type
- Conference
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Language
- English
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