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dc.contributor.authorKing, Maxine V.
dc.contributor.authorGales, Jenny A.
dc.contributor.authorLaberg, Jan Sverre
dc.contributor.authorMckay, Robert M.
dc.contributor.authorDe Santis, Laura
dc.contributor.authorKulhanek, Denise K.
dc.contributor.authorHosegood, Phil J.
dc.contributor.authorMorris, Antony
dc.contributor.authorIODP Expedition 374, Scientists
dc.date.accessioned2023-03-15T10:14:09Z
dc.date.available2023-03-15T10:14:09Z
dc.date.issued2021-10-22
dc.description.abstractThe repeated proximity of West Antarctic Ice Sheet (WAIS) ice to the eastern Ross Sea continental shelf break during past ice age cycles has been inferred to directly influence sedimentary processes occurring on the continental slope, such as turbidity current and debris flow activity; thus, the records of these processes can be used to study the past history of the WAIS. Ross Sea slope sediments may additionally provide an archive on the history and interplay of density-driven or geostrophic oceanic bottom currents with ice-sheet-driven depositional mechanisms. We investigate the upper 121 m of Hole U1525A, collected during International Ocean Discovery Program (IODP) Expedition 374 in 2018. Hole U1525A is located on the southwestern external levee of the Hillary Canyon (Ross Sea, Antarctica) and the depositional lobe of the nearby trough-mouth fan. Using core descriptions, grain size analysis, and physical properties datasets, we develop a lithofacies scheme that allows construction of a detailed depositional model and environmental history of past ice sheet-ocean interactions at the eastern Ross Sea continental shelf break/slope since ~2.4 Ma. The earliest Pleistocene interval (~2.4- ~ 1.4 Ma) represents a hemipelagic environment dominated by ice-rafting and reworking/deposition by relatively persistent bottom current activity. Finely interlaminated silty muds with ice-rafted debris (IRD) layers are interpreted as contourites. Between ~1.4 and ~0.8 Ma, geostrophic bottom current activity was weaker and turbiditic processes more common, likely related to the increased proximity of grounded ice at the shelf edge. Silty, normally-graded laminations with sharp bases may be the result of flow-stripped turbidity currents overbanking the canyon levee during periods when ice was grounded at or proximal to the shelf edge. A sandy, IRD- and foraminifera-bearing interval dated to ~1.18 Ma potentially reflects warmer oceanographic conditions and a period of stronger Antarctic Slope Current flow. This may have enhanced upwelling of warm Circumpolar Deep Water onto the shelf, leading to large-scale glacial retreat at that time. The thickest interval of turbidite interlamination was deposited after ~1 Ma, following the onset of the Mid-Pleistocene Transition, interpreted as a time when most ice sheets grew and glacial periods were longer and more extreme. Sedimentation after ~0.8 Ma was dominated by glacigenic debris flow deposition, as the trough mouth fan that dominates the eastern Ross Sea continental slope prograded and expanded over the site. These findings will help to improve estimations of WAIS ice extent in future Ross Sea shelf-based modelling studies, and provide a basis for more detailed analysis of the inception and growth of the WAIS under distinct oceanographic conditionsen_US
dc.identifier.citationKing, Gales JA, Laberg JS, Mckay RM, De Santis L, Kulhanek, Hosegood, Morris A, IODP Expedition 374. Pleistocene depositional environments and links to cryosphere-ocean interactions on the eastern Ross Sea continental slope, Antarctica (IODP Hole U1525A). Marine Geology. 2022;443:1-20en_US
dc.identifier.cristinIDFRIDAID 2012576
dc.identifier.doi10.1016/j.margeo.2021.106674
dc.identifier.issn0025-3227
dc.identifier.issn1872-6151
dc.identifier.urihttps://hdl.handle.net/10037/28761
dc.language.isoengen_US
dc.publisherElsevieren_US
dc.relation.journalMarine Geology
dc.relation.projectIDNatural Environment Research Council: NE/R018189/1en_US
dc.relation.projectIDNational Science Foundation: OPP-2000995en_US
dc.relation.projectIDNational Science Foundation: OCE-1326927en_US
dc.rights.accessRightsopenAccessen_US
dc.rights.holderCopyright 2022 The Author(s)en_US
dc.rights.urihttps://creativecommons.org/licenses/by/4.0en_US
dc.rightsAttribution 4.0 International (CC BY 4.0)en_US
dc.titlePleistocene depositional environments and links to cryosphere-ocean interactions on the eastern Ross Sea continental slope, Antarctica (IODP Hole U1525A)en_US
dc.type.versionacceptedVersionen_US
dc.typeJournal articleen_US
dc.typeTidsskriftartikkelen_US
dc.typePeer revieweden_US


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Attribution 4.0 International (CC BY 4.0)
Except where otherwise noted, this item's license is described as Attribution 4.0 International (CC BY 4.0)