Late Cenozoic oscillations of Antarctic ice sheets revealed
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TitleLate Cenozoic oscillations of Antarctic ice sheets revealed by provenance of basement clasts and grain detrital modes in ANDRILL core AND-1BAbstractPetrological investigations of the sand fraction and of granule- to cobble-sized clasts in the Plio-Pleistocene sedimentary cycles of the AND-1B drill core at the NW edge of the Ross Ice Shelf (McMurdo Sound) highlight significant down-core modal and compositional variations. These variations provide: (i) direct information about potential source regions during both glacial maxima and minima; and (ii) evidence of an evolving provenance, documented by long-term shifts in compositional patterns that can be interpreted as reflecting variations in ice volume and ice sheet thermal regimes and changes in paleogeography related to the emergence of several volcanic centres during the deposition of the drill core over the past ca. 3.5. Ma. The most significant change in diamictite provenance (identified at 82.7. metre below the sea floor, mbsf), coincides with a change in sedimentary cycle architecture from sequences that are dominated by diamictites (Mid-Late Pleistocene, above 82.7. mbsf) to sequences characterised by cycles of diamictite (subglacial) and diatomite (open-marine) deposition (Pliocene, below 82.7. mbsf). In the Mid-Late Pleistocene glacial/interglacial cycles diamictites show high amounts of Skelton-Mulock sourced clasts, supplied from both basement and overlying Beacon and Ferrar supergroups, and they also include a variable contribution from reworking of glacial sediments that were deposited during earlier glacial activity. In the Pliocene to early Pleistocene diatomite-diamictite cycles basement clast compositions indicate the same provenance (Mulock-Skelton) but the main debris load was picked up from volcanic centres in the McMurdo Sound area. Similarly, associated glacial minima sediments (i.e., diatomite intervals) are dominated by volcanic clasts suggesting calving of glaciers from Ross Island or the Koettlitz Glacier region during interglacials. In agreement with previous glaciological reconstructions and numerical ice sheet models, the provenance of glacially transported material is firmly identified in the region between Ross Island and the Skelton-Mulock glacier area (South Victoria Land). The reconstructed ice directions and ice dynamic model are comparable to the configurations proposed for the grounded ice expansion within the McMurdo Sound during the Last Glacial Maximum, and they are also consistent with ice-flow patterns previously reconstructed for Pliocene and Pleistocene glacial settings in the region. Copyright 2009 Elsevier B.V.AcknowledgementsWe would like to acknowledge G. S. Wilson and two anonymous referees for their helpful comments and suggestions, and the whole ANDRILL MIS Science Team for their contribution to the successful drilling project. The research was carried out with the financial support of the Italian Programma Nazionale di Ricerche in Antaride. The ANDRILL project is a multinational collaboration between the Antarctic programmes of Germany, Italy, New Zealand and the United States. Antarctica New Zealand is the project operator and developed the drilling system in collaboration with Alex Pyne at Victoria University of Wellington and Webster Drilling and Enterprises Ltd. Antarctica New Zealand supported the drilling team at Scott Base; Raytheon Polar Services Corporation supported the science team at McMurdo Station and the Crary Science and Engineering Laboratory. The ANDRILL Science Management Office at the University of Nebraska--Lincoln provided science planning and operational support. Scientific studies are jointly supported by the US National Science Foundation, NZ Foundation for Research, Science and Technology and the Royal Society of NZ Marsden Fund, the Italian Antarctic Research Programme, the German Research Foundation (DFG) and the Alfred Wegener Institute Polar and Marine Research.
1st AuthorTalarico, F.AuthorTalarico, F.McKay, R.Powell, R.Sandroni, S.Naish, T.Year2012JournalGlobal and Planetary ChangeVolume96-97Pages23-40DOI10.1016/j.gloplacha.2009.12.002URLhttps://www.scopus.com/inward/recor.....cfb45126548bb6e51f2b102f0KeywordsCompositional variationDrill coreGlacial activityGlacial maximaGlacial sedimentsIce sheetIce sheet modelsIce volumesInterglacialsLast Glacial MaximumLate CenozoicPaleogeographyPleistocenePleistocene glacialPlio-pleistocenePliocenePotential source regionsProvenanceRoss ice shelvesSand fractionSea floorThermal regimesTransported materials, BuildingsCore drillingDebrisGlaciersIceSedimentologyVolcanoes, Glacial geology, clastdebris flowdiamictitedrillingglacial depositglacial-interglacial cycleice flowice sheetice shelflong-term changenumerical modelpaleogeographypetrologyPliocene-Pleistocene boundaryprovenancereconstructionreworkingsandsedimentary sequencevolcanism, AntarcticaEast AntarcticaMcMurdo SoundRoss Ice ShelfRoss IslandWest Antarctica, rank5Author KeywordsEast Antarctic Ice SheetPleistocenePlioceneProvenanceWest Antarctic Ice Sheet
TypeArticleCitationTalarico, F., McKay, R., Powell, R., Sandroni, S. and Naish, T. (2012) Late Cenozoic oscillations of Antarctic ice sheets revealed by provenance of basement clasts and grain detrital modes in ANDRILL core AND-1B. Global and Planetary Change, 96-97:23-40 doi:10.1016/j.gloplacha.2009.12.002
Antarctica NZ (26th Nov 2018). Late Cenozoic oscillations of Antarctic ice sheets revealed . In Website Antarctica NZ. Retrieved 6th Dec 2021 15:34, from https://adam.antarcticanz.govt.nz/nodes/view/63792