Seismic stratigraphy of the Central Basin in northwestern Ross Sea slope and rise, Antarctica: Clues to the late Cenozoic ice-sheet dynamics and bottom-current activity

• Published in: Marine Geology
• Main Authors: Sookwan Kim, Laura De Santis, Jong Kuk Hong, Diego Cotterle, Lorenzo Petronio, Ester Colizza, Young-Gyun Kim, Seung-Goo Kang, Hyoung Jun Kim, Suhwan Kim, Nigel Wardell, Riccardo Geletti, Andrea Bergamasco, Robert McKay, Young Keun Jin, Sung-Ho Kan
• Other Authors: Kim, Sookwan, De Santis, Laura, Kuk Hong, Jong, Cotterle, Diego, Petronio, Lorenzo, Colizza, Ester, Kim, Young-Gyun, Kang, Seung-Goo, Jun Kim, Hyoung, Kim, Suhwan, Wardell, Nigel, Geletti, Riccardo, Bergamasco, Andrea, Mckay, Robert, Keun Jin, Young, Kan, Sung-Ho
• Format: Article in Journal/Newspaper
• Language: English
• Published: 2018
• Subjects: Antarctica; Ross Sea; Seismic stratigraphy; Contourite; Glacial sediment; Sedimentary proces; Antarctic; Joides Basin; Central Basin; Antarc*; Ice Sheet
• Online Access: http://hdl.handle.net/11368/2941788; https://doi.org/10.1016/j.margeo.2017.10.013; https://www.sciencedirect.com/science/article/pii/S0025322717302827

Sedimentation processes in fluenced by late Cenozoic ice-sheet dynamics and bottom-current activity can be extracted from the seismic stratigraphic record of the Ross Sea continental slope and rise, where more con- tinuous sedimentary successions are preserved compared to the continental shelf. In this study, we present a seismic stratigraphic analysis of the Central Basin that lies in the northwestern Ross Sea, using newly acquired and existing legacy seismic reflection data that are correlated to adjacent scientific drill sites. The chronos- tratigraphy of Ross Sea seismic sequences lying above the mid-Miocene sequence boundary (RSU4, ca. 16.5–15.5 Ma) is based on the former Antarctic Offshore Stratigraphy (ANTOSTRAT) project. Depth-contour and isopach maps of sedimentary sequences bounded by two major unconformities of RSU4 and RSU2 (the late Pliocene boundary, ca. 4.0–2.8 Ma) and the present-day seafloor were produced to illustrate the evolution of paleo-seafloor morphology, distribution of sediments and depocenter migration in the western Ross Sea outer margin. The results of seismic stratigraphic analysis indicate that gravity sedimentation processes dominated the Central Basin infill up to the mid-Miocene, and then downslope sediment supply gradually diminished through the late Miocene and Quaternary, likely reflecting a shift toward a cooler, less erosive glacial regime change. Since the late Pliocene, a topset-truncated glacial prograding wedge developed in the upper continental slope at the mouth of the Joides Basin and the sediment depocenter was shifted from the basin floor to the upper slope, suggesting the more persistent occurrence of grounded ice sheets on the outer continental shelf. Meanwhile, persistent along-slope bottom-current processes formed contourites on the slope and over the crests of banks surrounding the Central Basin since the mid-Miocene. In the late Pliocene, the contourites that formed offthe Joides Basin mouth were overlain by glaciogenic debrisflows, while the growth of ...