Spatial distribution of deepwater depositional systems and relationship with bottom currents on the northwestern lower slope of the Northwest Sub-Basin, South China Sea
Xie, X.; Chen, H.; Xie, Y.; Wang, Z.; Yongchao, L.; Ren, J. (2014). Spatial distribution of deepwater depositional systems and relationship with bottom currents on the northwestern lower slope of the Northwest Sub-Basin, South China Sea, in: Van Rooij, D. et al. (Ed.) Book of Abstracts. 2nd Deep-Water Circulation Congress: The Contourite Log-book. Ghent, Belgium, 10-12 September 2014. VLIZ Special Publication, 69: pp. 13-14 In: Van Rooij, D.; Rüggeberg, A. (Ed.) (2014). Book of Abstracts. 2nd Deep-Water Circulation Congress: The Contourite Log-book. Ghent, Belgium, 10-12 September 2014. VLIZ Special Publication, 69. Ghent University, Department of Geology and Soil Science/Flanders Marine Institute (VLIZ): Oostende. xviii, 152 pp., more In: VLIZ Special Publication. Vlaams Instituut voor de Zee (VLIZ): Oostende. ISSN 1377-0950, more |  |
| Available in | Authors | | Document type: Summary
|
| Keywords | Sediments > Clastics > Contourites
ISEW, South China Sea [Marine Regions]
Marine/Coastal | | Author keywords | Deepwater system; Turbidite deposits; Northwest sub-basin |
| Authors | | Top | - Xie, X.
- Chen, H., more
- Xie, Y.
| - Wang, Z.
- Yongchao, L.
- Ren, J.
| |
| Abstract | Using 2D seismic data, a complex of deepwater depositional systems consisting of submarine valleys/canyons, wave-shaped sliding deposits, contourite erosive features and sheeted drifts, are developed within the Quaternary strata on the northwestern lower slopes of the Northwestern Sub-Basin, South China Sea. Alongslope aliened erosive features and non-depositional features are observed on the eastern upper gentle slopes (<1500m-depth), where a V-shaped downslope valley presents an apparent ENE migration. These indicate a major eastward bottom current, possibly within the South China Sea Intermediate Water Circulation. Contourite sheeted drifts are also present on the eastern gentle slopes, with water depth >2500m, referring to a wide unfocused bottom current, which might be related to the South China Sea Deep Water Circulation. Sliding deposits are developed on steeper slopes (>2o), where alongslope current deposition is missing. This suggests a domination of downslope depositional processes on unsteady slopes. The NNW-SSE oriented slope morphology changes from a three-step terraced outline (gentle-steep-gentle) in the east of the investigated area, into a two-step terraced (gentlesteep) outline in the middle, and into a unitary steep slope in the west. Such morphological changes possibly lead to the westwards simplifying assemble patterns of the deepwater depositional systems on this margin. |
|
