TY - JOUR

T1 - Depositional and erosional signatures in sedimentary successions on the continental slope and rise off Prydz Bay, East Antarctica– implications for Pliocene paleoclimate

AU - Huang, Xiaoxia

AU - Bernhardt, Anne

AU - De Santis, Laura

AU - Wu, Shiguo

AU - Leitchenkov, German

AU - Harris, Peter

AU - O'Brien, Philip

N1 - Funding Information: We thank the finance supports of The National Natural Science Foundation of China ( 41976233 ), and the Key Research Program of Frontier Sciences , CAS, Grant No. ZDBS-LY-7018 , and Pioneer Hundred Talents Program ( Y910091001 ) Chinese Academy of Sciences (CAS). Dr. Graeme Eagles is acknowledged for his constructive comments on the first draft of this work. Schlumberger is acknowledged for the donation of the Petrel ( ∗ ) license. This research is a contribution to the Past Antarctic Ice Sheet dynamics (PAIS) program of the Scientific Committee for Antarctic Research (SCAR). Publisher Copyright: © 2020 The Authors Copyright: Copyright 2020 Elsevier B.V., All rights reserved.

PY - 2020/12

Y1 - 2020/12

N2 - The Prydz Bay region of Antarctica is the immediate recipient of ice and sediments transported by the Lambert Glacier, the single largest outflow from the East Antarctic Ice Sheet. The continental slope and rise provide records covering multiple glacial cycles and containing paleoclimatic information. Marine geological and geophysical data collected from the continental shelf and adjacent slope of Prydz Bay, Antarctica, including seismic reflection data, bathymetry, and core records from ODP drilling sites, reveal the history of glacial sediment transport and deposition since the early Pliocene times. Seismic facies are interpreted in terms of episodes of slope progradation, contourite, turbidite, trough-mouth fan, and mass transport deposition. Two seismic units with estimated age of early to late Pliocene and late Pliocene to recent have been analyzed in detail for the area immediately offshore the Lambert Glacier and Prydz Bay and the adjacent Mac. Robertson margin. The upper slope is dominated by episodic mass transport deposits, many of which accumulated to form a trough mouth fan since Early Pliocene times. The trough mouth fan contrasts with the adjacent steep (4–6°) continental slope of the Mac. Robertson margin, where glacigenic sediments have been transported down slope as high-velocity turbidity currents via submarine channels. The distal region exhibits evidence for contrasting effects of high-energy, traction-dominated versus lower-energy, fallout-dominated suspension flows. The counter-clockwise Coriolis force modifies the erosion and deposition patterns of turbidity currents creating an asymmetric channel-levee architecture. Since the early Pliocene, turbidite sedimentation surpassed the amount of sediment reworked and transported by westward-flowing contour currents along the base of slope. On the continental rise, contourites and sediment waves were deposited in response to enhanced bottom-water formation, which is consistent with climatic cooling since late Pliocene times. This study, based on existing seismic reflection and ODP data, highlights the need for a future scientific ocean drilling proposal on the Prydz Bay continental slope and rise in order to more accurately determine the timing of the important events that have influenced the evolution of this margin.

AB - The Prydz Bay region of Antarctica is the immediate recipient of ice and sediments transported by the Lambert Glacier, the single largest outflow from the East Antarctic Ice Sheet. The continental slope and rise provide records covering multiple glacial cycles and containing paleoclimatic information. Marine geological and geophysical data collected from the continental shelf and adjacent slope of Prydz Bay, Antarctica, including seismic reflection data, bathymetry, and core records from ODP drilling sites, reveal the history of glacial sediment transport and deposition since the early Pliocene times. Seismic facies are interpreted in terms of episodes of slope progradation, contourite, turbidite, trough-mouth fan, and mass transport deposition. Two seismic units with estimated age of early to late Pliocene and late Pliocene to recent have been analyzed in detail for the area immediately offshore the Lambert Glacier and Prydz Bay and the adjacent Mac. Robertson margin. The upper slope is dominated by episodic mass transport deposits, many of which accumulated to form a trough mouth fan since Early Pliocene times. The trough mouth fan contrasts with the adjacent steep (4–6°) continental slope of the Mac. Robertson margin, where glacigenic sediments have been transported down slope as high-velocity turbidity currents via submarine channels. The distal region exhibits evidence for contrasting effects of high-energy, traction-dominated versus lower-energy, fallout-dominated suspension flows. The counter-clockwise Coriolis force modifies the erosion and deposition patterns of turbidity currents creating an asymmetric channel-levee architecture. Since the early Pliocene, turbidite sedimentation surpassed the amount of sediment reworked and transported by westward-flowing contour currents along the base of slope. On the continental rise, contourites and sediment waves were deposited in response to enhanced bottom-water formation, which is consistent with climatic cooling since late Pliocene times. This study, based on existing seismic reflection and ODP data, highlights the need for a future scientific ocean drilling proposal on the Prydz Bay continental slope and rise in order to more accurately determine the timing of the important events that have influenced the evolution of this margin.

KW - Antarctica

KW - Mass-transports deposits

KW - Prydz Bay

KW - Sediment drifts

KW - Submarine canyons

UR - http://www.scopus.com/inward/record.url?scp=85094316046&partnerID=8YFLogxK

U2 - 10.1016/j.margeo.2020.106339

DO - 10.1016/j.margeo.2020.106339

M3 - Article

AN - SCOPUS:85094316046

VL - 430

JO - Marine Geology

JF - Marine Geology

SN - 0025-3227

M1 - 106339

ER -