Zoned facies of mass-flow deposits in the Ulleung (Tsushima) Basin, East Sea (Sea of Japan)
In: Marine Geology. Elsevier: Amsterdam. ISSN 0025-3227; e-ISSN 1872-6151, meer
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| Auteurs | | Top |
- Chough, S.K.
- Jeong, K.S.
- Honza, E.
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| Abstract |
High-resolution (3.5 kHz) reflection profiles in the Ulleung (Tsushima) Basin made it possible to classify the uppermost (ca. 50 m thick) sedimentary deposits into rock fall, slide, slump, debris-flow deposit (debrite) and turbidite in terms of their acoustic properties. These deposits generally occur in a distinctive zonal facies: slides and slumps on the slope; debrites on the base-of-slope; and turbidites on the basin floor. The rock-fall deposits occur along the bases of the Korea Plateau and Ulleung and Dok Islands.The zonal distribution of mass-flow deposits suggests that they most likely are derived from a line source at the shelfbreak. Shelf sediments prograde toward the shelfbreak. On the slope, sediment masses move downslope mainly, accompanied by progressive slumping upslope. Individual slides and slumps on the slope probably develop into debris flows on the base-of-slope and successively into turbidity currents on the basin floor. Mass-flow processes on the Ulleung Basin slope played an important role in transporting a large volume of terrigenous sediments into the deep basin. |
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