Depositional features of co-genetic turbidite-debrite beds and possible mechanisms for their formation in distal mass-flow lobes beyond the base-of-slope, Ulleung Basin, East Sea

Title
Depositional features of co-genetic turbidite-debrite beds and possible mechanisms for their formation in distal mass-flow lobes beyond the base-of-slope, Ulleung Basin, East Sea
Author(s)
이상훈; 정우열; 박장준; Joan M. Gardner; 박준용; 이희준; 김진경; 이수환
KIOST Author(s)
Lee, Sang Hoon(이상훈)Park, Jun Yong(박준용)Lee, Hee Jun(이희준)Lee, Su Hwan(이수환)
Alternative Author(s)
이상훈; 박준용; 이희준; 김진경; 이수환
Publication Year
2012-10-24
Abstract
A detailed analysis of the MR1 (11−12 kHz) sonar images, chirp (2−7 kHz) profiles,core sediments and 14C ages from the latest Quaternary mass-flow lobes on the deep(>2,100 m water depth) basin plain of the western Ulleung Basin reveals various depositional processes of mass flows in the distal setting beyond the base-of-slope and changes in slope-failure style. Eight mass-flow lobes are present in the basin plain, ca. 30−60 km beyond the base-of-slope, and were generally deposited retrogressively. Lobes 1−4 (distal lobes) are longer (>27 km) and wider (15−25 km) than lobes 5−8 (proximal lobes) having the length of 8.8−31.5 km and the width of 1.2−12 km. Lobes 1 and 2 consist dominantly of the muddier mass-flow deposits deposited between 19.5 and 20.0 cal. ka B.P. after the Last Glacial Maximum. The relatively huge masses with the high content of muds failed on the muddy upper slopes, deeper than 350−400 m water depth. On other hand, the sandier, smaller lobes 6 and 7 were deposited between 16.5 and 17 cal. ka B.P., probably by sediment failures on the sandy uppermost slope, shallower than 350−400 m water depth. Lobe 1 consists of a lower sandy-mud turbidite grading upward into an upper mud-matrix debrite having small, rounded mud clasts. In contrast, the mass-flow bed of lobe 6 is characterized by a gradual upward change from a lower clay-posin reveals various depositional processes of mass flows in the distal setting beyond the base-of-slope and changes in slope-failure style. Eight mass-flow lobes are present in the basin plain, ca. 30−60 km beyond the base-of-slope, and were generally deposited retrogressively. Lobes 1−4 (distal lobes) are longer (>27 km) and wider (15−25 km) than lobes 5−8 (proximal lobes) having the length of 8.8−31.5 km and the width of 1.2−12 km. Lobes 1 and 2 consist dominantly of the muddier mass-flow deposits deposited between 19.5 and 20.0
URI
https://sciwatch.kiost.ac.kr/handle/2020.kiost/27501
Bibliographic Citation
2012추계지질과학연합학술대회, pp.13, 2012
Publisher
대한지질학회
Type
Conference
Language
English
Publisher
대한지질학회
Related Researcher
Research Interests

Marine Geology,Marine Sedimentary Environments and Processes,Submarine slope failures and stability,해양지질,해양퇴적 환경 및 작용,해저사면 사태 및 안정성

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