Early to Middle Miocene sea-level oscillations of approximately 40–60 m estimated from far-field records1,2,3 are interpreted to reflect the loss of virtually all East Antarctic ice during peak warmth2. This contrasts with ice-sheet model experiments suggesting most terrestrial ice in East Antarctica was retained even during the warmest intervals of the Middle Miocene4,5. Data and model outputs can be reconciled if a large West Antarctic Ice Sheet (WAIS) existed and expanded across most of the outer continental shelf during the Early Miocene, accounting for maximum ice-sheet volumes. Here we provide the earliest geological evidence proving large WAIS expansions occurred during the Early Miocene (~17.72–17.40 Ma). Geochemical and petrographic data show glacimarine sediments recovered at International Ocean Discovery Program (IODP) Site U1521 in the central Ross Sea derive from West Antarctica, requiring the presence of a WAIS covering most of the Ross Sea continental shelf. Seismic, lithological and palynological data reveal the intermittent proximity of grounded ice to Site U1521. The erosion rate calculated from this sediment package greatly exceeds the long-term mean, implying rapid erosion of West Antarctica. This interval therefore captures a key step in the genesis of a marine-based WAIS and a tipping point in Antarctic ice-sheet evolution.
This is a preview of subscription content, access via your institution
Subscribe to Nature+
Get immediate online access to Nature and 55 other Nature journal
Subscribe to Journal
Get full journal access for 1 year
only $3.90 per issue
All prices are NET prices.
VAT will be added later in the checkout.
Tax calculation will be finalised during checkout.
Get time limited or full article access on ReadCube.
All prices are NET prices.
The data sets generated as part of this study are available in the British Geological Survey National Geoscience Data Centre. Data sets include Nd and Sr isotope data (https://doi.org/10.5285/3a646c8a-8422-4079-a928-a159532439eb), zircon U-Pb dates (https://doi.org/10.5285/cfadf931-0804-484c-a9d0-96254239c421), clast counts (https://doi.org/10.5285/b043471f-22e5-40e4-b274-1c875316d725), clay mineralogy data (https://doi.org/10.5285/b3cb3574-49b0-44c8-a934-3da88ca4ef93), hornblende 40Ar/39Ar dates (https://doi.org/10.5285/926cad28-669f-4703-8a5b-5e7e843a4ee1) and palynological counts (https://doi.org/10.5285/adea0809-5fe5-4fb5-9f3e-9d774534d26d). Source data are provided with this paper.
Kominz, M. A. et al. Miocene relative sea level on the New Jersey shallow continental shelf and coastal plain derived from one-dimensional backstripping: A case for both eustasy and epeirogeny. Geosphere 12, 1437–1456 (2016).
Miller, K. G. et al. Cenozoic sea-level and cryospheric evolution from deep-sea geochemical and continental margin records. Sci. Adv. 6, eaaz1346 (2020).
Pekar, S. F. & DeConto, R. M. High-resolution ice-volume estimates for the early Miocene: Evidence for a dynamic ice sheet in Antarctica. Palaeogeogr. Palaeoclimatol. Palaeoecol. 231, 101–109 (2006).
Gasson, E., DeConto, R. M., Pollard, D. & Levy, R. H. Dynamic Antarctic ice sheet during the early to mid-Miocene. Proc. Natl Acad. Sci. USA 113, 3459–3464 (2016).
Paxman, G. J., Gasson, E. G., Jamieson, S. S., Bentley, M. J., & Ferraccioli, F. Long‐term increase in antarctic ice sheet vulnerability driven by bed topography evolution. Geophys. Res. Lett. 47, e2020GL090003 (2020).
Masson-Delmotte, V. et al. in Climate Change 2013: The Physical Science Basis (eds Stocker, T. F. et al.) 383–464 (IPCC, Cambridge Univ. Press, 2013).
Kennicutt, M. C. et al. A roadmap for Antarctic and Southern Ocean science for the next two decades and beyond. Antarct. Sci. 27, 3–18 (2014).
Kennett, J. P. Cenozoic evolution of Antarctic glaciation, the circum‐Antarctic Ocean, and their impact on global paleoceanography. J. Geophys. Res. 82, 3843–3860 (1977).
Barrett, P. J. Characteristics of pebbles from Cenozoic marine glacial sediments in the Ross Sea (DSDP Sites 270–274) and the South Indian Ocean (Site 268). Initial Rep. Deep Sea Drill. Proj. 28, 769–784 (1975).
Passchier, S. & Krissek, L. A. Oligocene–Miocene Antarctic continental weathering record and paleoclimatic implications, Cape Roberts drilling project, Ross Sea, Antarctica. Palaeogeogr. Palaeoclimatol. Palaeoecol. 260, 30–40 (2008).
Levy, R. et al. Antarctic ice sheet sensitivity to atmospheric CO2 variations in the early to mid-Miocene. Proc. Natl Acad. Sci. USA 113, 3453–3458 (2016).
Zachos, J., Pagani, M., Sloan, L., Thomas, E. & Billups, K. Trends, rhythms, and aberrations in global climate 65 Ma to present. Science 292, 686–693 (2001).
Kennett, J. P. & Barker, P. F. Latest Cretaceous to Cenozoic climate and oceanographic developments in the Weddell Sea, Antarctica: an ocean-drilling perspective. Proc. Ocean Drill. Program, Sci. Results 113, 937–960 (1990).
Hauptvogel, D. W. & Passchier, S. Early–Middle Miocene (17–14 Ma) Antarctic ice dynamics reconstructed from the heavy mineral provenance in the AND-2A drill core, Ross Sea, Antarctica. Global Planet. Change 82, 38–50 (2012).
Levy, R. H. et al. Antarctic ice-sheet sensitivity to obliquity forcing enhanced through ocean connections. Nat. Geosci. 12, 132–137 (2019).
Colleoni, F. et al. Past continental shelf evolution increased Antarctic ice sheet sensitivity to climatic conditions. Sci. Rep. 8, 1–12 (2018).
Wilson, D. S. et al. Antarctic topography at the Eocene‐Oligocene boundary. Palaeogeogr. Palaeoclimatol. Palaeoecol. 335‐336, 24–34 (2012).
Paxman, G. J. et al. Reconstructions of Antarctic topography since the Eocene–Oligocene boundary. Palaeogeogr. Palaeoclimatol. Palaeoecol. 535, 109346 (2019).
Gasson, E. G. & Keisling, B. A. The Antarctic Ice Sheet: A Paleoclimate modelling perspective. Oceanography (Wash. D.C.) 33, 90–100 (2020).
Anderson, J. B. & Bartek, L. R. in The Antarctic Paleoenvironment: A Perspective on Global Change. Part One Vol. 56 (eds Kennett, J.P & Warkne, D. A.) 231–264 (AGU, 1992).
De Santis, L., Anderson, J. B., Brancolini, G. & Zayatz, I. in Geology and Seismic Stratigraphy of the Antarctic Margin Vol. 68 (eds Cooper, A. K., Barker, P. F. & Brancolini, G.) 235–260 (AGU, 1995).
Gohl, K. et al. Seismic stratigraphic record of the Amundsen Sea Embayment shelf from pre-glacial to recent times: Evidence for a dynamic West Antarctic Ice Sheet. Mar. Geol. 344, 115–131 (2013).
Pérez, L. F. et al. Early-middle Miocene ice sheet dynamics in the Ross Sea embayment: results from integrated core-log-seismic interpretation. Geol. Soc. Am. Bull. https://doi.org/10.1130/B35814.1 (2021).
Bart, P. J. Were West Antarctic ice sheet grounding events in the Ross Sea a consequence of East Antarctic ice sheet expansion during the middle Miocene? Earth Planet. Sci. Lett. 216, 93–107 (2003).
Chow, J. M. & Bart, P. J. West Antarctic Ice Sheet grounding events on the Ross Sea outer continental shelf during the middle Miocene. Palaeogeogr. Palaeoclimatol. Palaeoecol. 198, 169–186 (2003).
McKay, R., De Santis, L. & Kulhanek, D. K. and the Expedition 374 Science Party. Ross Sea West Antarctic Ice Sheet History in Proc. Int. Ocean Discovery Program (IODP, 2019).
Licht, K. J. & Hemming, S. R. Analysis of Antarctic glacigenic sediment provenance through geochemical and petrologic applications. Quat. Sci. Rev. 164, 1–24 (2017).
Farmer, G. L., Licht, K., Swope, R. J. & Andrews, J. Isotopic constraints on the provenance of fine-grained sediment in LGM tills from the Ross Embayment, Antarctica. Earth Planet. Sci. Lett. 249, 90–107 (2006).
van Wyck de Vries, M., Bingham, R. G. & Hein, A. S. in Exploration of Subsurface Antarctica: Uncovering Past Changes and Modern Processes (eds Siegert, M. J., Jamieson, S. S. R. & White, D. A.) https://doi.org/10.1144/SP461.7 (Geological Society, 2017).
Farmer, G. L. & Licht, K. J. Generation and fate of glacial sediments in the central Transantarctic Mountains based on radiogenic isotopes and implications for reconstructing past ice dynamics. Quat. Sci. Rev. 150, 98–109 (2016).
Goodge, J. W. Geological and tectonic evolution of the Transantarctic Mountains, from ancient craton to recent enigma. Gondwana Res. 80, 50–122 (2020).
Licht, K. J. & Palmer, E. F. Erosion and transport by Byrd Glacier, Antarctica during the last glacial maximum. Quat. Sci. Rev. 62, 32–48 (2013).
Licht, K. J., Hennessy, A. J. & Welke, B. M. The U-Pb detrital zircon signature of West Antarctic ice stream tills in the Ross embayment, with implications for Last Glacial Maximum ice flow reconstructions. Antarct. Sci. 26, 687–697 (2014).
Bader, N. A., Licht, K. J., Kaplan, M. R., Kassab, C. & Winckler, G. East Antarctic ice sheet stability recorded in a high-elevation ice-cored moraine. Quat. Sci. Rev. 159, 88–102 (2017).
Kyle, R. A. & Schopf, J. M. in Antarctic Geoscience (ed. Craddock, C.) 649–659 (Univ. Wisconsin Press, 1982).
Perotti, M., Andreucci, B., Talarico, F., Zattin, M. & Langone, A. Multianalytical provenance analysis of Eastern Ross Sea LGM till sediments (Antarctica): Petrography, geochronology, and thermochronology detrital data. Geochem. Geophys. Geosyst. 18, 2275–2304 (2017).
Jordan, T. A., Riley, T. R. & Siddoway, C. S. The geological history and evolution of West Antarctica. Nat. Rev. Earth Environ. 1, 117–133 (2020).
Balshaw-Biddle, K. M. Antarctic Glacial Chronology Reflected in the Oligocene through Pliocene Sedimentary Section in the Ross Sea PhD Thesis, Rice University (1981).
Westerhold, T. et al. An astronomically dated record of Earth’s climate and its predictability over the last 66 million years. Science 369, 1383–1387 (2020).
Koppes, M. et al. Observed latitudinal variations in erosion as a function of glacier dynamics. Nature 526, 100–103 (2015).
Alley, R. B., Cuffey, K. M. & Zoet, L. K. Glacial erosion: status and outlook. Ann. Glaciol. 60, 1–13 (2019).
Cox, S. C., Smith Lyttle, B. and the GeoMAP team. SCAR GeoMAP dataset. GNS Science, Lower Hutt, New Zealand. Release v.201907 https://doi.org/10.21420/7SH7-6K05 (2019).
Morlighem, M. MEaSUREs BedMachine Antarctica, Version 1 (Boulder, Colorado USA. NASA National Snow and Ice Data Center Distributed Active Archive Center, 2019; accessed 10 June 2021); https://doi.org/10.5067/C2GFER6PTOS4.
Morlighem, M. et al. Deep glacial troughs and stabilizing ridges unveiled beneath the margins of the Antarctic ice sheet. Nat. Geosci. 13, 132–137 (2020).
Mouginot, J., Scheuchl, B. & Rignot. E. MEaSUREs Antarctic Boundaries for IPY 2007–2009 from Satellite Radar, Version 2 (Boulder, Colorado USA. NASA National Snow and Ice Data Center Distributed Active Archive Center, 2017; accessed 12 June 2020); https://doi.org/10.5067/AXE4121732AD.
Rignot, E., Jacobs, S. S., Mouginot, J. & Scheuchl, B. Ice-shelf melting around. Antarct. Sci. 341, 266–270 (2013).
Tinto, K. J. et al. Ross Ice Shelf response to climate driven by the tectonic imprint on seafloor bathymetry. Nat. Geosci. 12, 441–449 (2019).
Vermeesch, P. Statistical models for point-counting data. Earth Planet. Sci. Lett. 501, 112–118 (2018).
Ogg, J. Geomagnetic Polarity Time Scale. In Geologic Time Scale 2020 (eds Gradstein, F. M. et al.) 159–192 (Elsevier, 2020).
Rae, J. W. et al. Atmospheric CO2 over the past 66 million years from marine archives. Annu. Rev. Earth Planet. Sci. 49, 599–631 (2021).
Vermeesch, P. Multi-sample comparison of detrital age distributions. Chem. Geol. 341, 140–146 (2013).
Goldstein, S. L. & Hemming, S. R. in Treatise on Geochemistry (eds Holland, H. D. & Turekian, K. K.) 453–489 (Pergamon, 2003).
Garçon, M., Chauvel, C., France-Lanord, C., Huyghe, P. & Lavé, J. Continental sedimentary processes decouple Nd and Hf isotopes. Geochim. Cosmochim. Acta 121, 177–195 (2013).
Gutjahr, M. et al. Reliable extraction of a deepwater trace metal isotope signal from Fe–Mn oxyhydroxide coatings of marine sediments. Chem. Geol. 242, 351–370 (2007).
Simões Pereira, P. et al. Geochemical fingerprints of glacially eroded bedrock from West Antarctica: D–etrital thermochronology, radiogenic isotope systematics and trace element geochemistry in Late Holocene glacial-marine sediments. Earth Sci. Rev. 182, 204–232 (2018).
Tanaka, T. et al. JNdi-1: a neodymium isotopic reference in consistency with LaJolla neodymium. Chem. Geol. 168, 279–281 (2000).
Weis, D. et al. High-precision isotopic characterization of USGS reference materials by TIMS and MC-ICP-MS. Geochem. Geophys. Geosyst. 7, Q08006 (2006).
Jacobsen, S. B. & Wasserburg, G. J. Sm-Nd isotopic evolution of chondrites. Earth Planet. Sci. Lett. 50, 139–155 (1980).
Sláma, J. et al. Plešovice zircon—a new natural reference material for UPb and Hf isotopic microanalysis. Chem. Geol. 249, 1–35 (2008).
Pearce, N. J. et al. A compilation of new and published major and trace element data for NIST SRM 610 and NIST SRM 612 glass reference materials. Geostand. Newsl. 21, 115–144 (1997).
Griffin, W. L. in Laser Ablation ICP-MS in the Earth Sciences: Current Practices and Outstanding Issues (ed. Sylvester, P.) 308–311 (Mineralogical Association of Canada, 2008).
Vermeesch, P. How many grains are needed for a provenance study? Earth Planet. Sci. Lett. 224, 441–451 (2004).
Jackson, S. E., Pearson, N. J., Griffin, W. L. & Belousova, E. A. The application of laser ablation-inductively coupled plasma-mass spectrometry to in situ U–Pb zircon geochronology. Chem. Geol. 211, 47–69 (2004).
Vermeesch, P. & Isoplot, R. A free and open toolbox for geochronology. Geoscience Frontiers 9, 1479–1493 (2018).
Talarico, F. & Sandroni, S. Petrography, mineral chemistry and provenance of basement clasts in the CRP-1 drillcore (Victoria Land Basin, Antarctica). Terra Antarct. 5, 601–610 (1998).
Talarico, F. & Sandroni, S. Provenance signature of the Antarctic Ice Sheets in the Ross Embayment during the Late Miocene to Early Pliocene: the ANDRILL AND-1B core record. Global Planet. Change 69, 103–123 (2009).
Talarico, F., Sandroni, S., Fielding, C. R. & Atkins, C. Variability, petrography and provenance of basement clasts from CRP-2/2A drillcore (Victoria Land Basin, Ross Sea, Antarctica). Terra Antarct. 7, 529–544 (2000).
Sandroni, S. & Talarico, F. M. Petrography and provenance of basement clasts and clast variability in CRP-3 drillcore (Victoria Land Basin, Antarctica). Terra Antarct. 8, 449–467 (2001).
Wood, G. D., Gabriel, A. M. & Lawson, J. C. in Palynology: Principles and Applications (eds Jansonius, J. & McGregor, D. C.) 29–50 (American Association of Stratigraphic Palynologists Foundation, 1996).
Raine, J. I., Mildenhall, D. C. & Kennedy, E. M. New Zealand Fossil Spores and Pollen: An Illustrated Catalogue (GNS Science Miscellaneous Series No. 4, 4th edition, 2011); http://data.gns.cri.nz/sporepollen/index.htm
Prebble, J. G. Descriptions and occurrences of pollen and spores from New Zealand Cenozoic sediments. GNS Science Internal Report 2016, 137 (2016).
Askin, R. A. in Palaeobiology and Palaeoenvironments of Eocene Rocks, McMurdo Sound, East Antarctica Antarctic Research Series v76 (eds Stilwel, J. D. & Feldman, R. M.) 161–181 (American Geophysical Union, 2000).
Askin, R. A. & Raine, J. I. Oligocene and Early Miocene terrestrial palynology of the Cape Roberts Drillhole CRP-2/2A, Victoria Land Basin, Antarctica. Terra Antarct. 7, 493–501 (2000).
Truswell, E. M. Recycled Cretaceous and Tertiary pollen and spores in Antarctic marine sediments: a catalogue. Palaeontographica Abt. B Paläophytol. 186, 121–174 (1983).
Fensome, R. A. & Williams, G. L. The Lentin and Williams Index of Fossil Dinoflagellates (American Association of Stratigraphic Palynologists Foundation Contribution Series 42, 2004).
Hannah, M. J., Wilson, G. J. & Wrenn, J. H. Oligocene and miocene marine palynomorphs from CRP-2/2A, Victoria Land Basin, Antarctica. Terra Antarct. 7, 503–511 (2000).
Hannah, M. J. The palynology of ODP site 1165, Prydz Bay, East Antarctica: a record of Miocene glacial advance and retreat. Palaeogeogr. Palaeoclimatol. Palaeoecol. 231, 120–133 (2006).
Clowes, C. D., Hannah, M. J., Wilson, G. J. & Wrenn, J. H. Marine palynostratigraphy of the Cape Roberts Drill-holes, Victoria Land Basin, Antarctica, with descriptions of six new species of organic-walled dinoflagellate cyst. Mar. Micropaleontol. 126, 65–84 (2016).
Bijl, P. et al. Stratigraphic calibration of Oligocene–Miocene organic-walled dinoflagellate cysts from offshore Wilkes Land, East Antarctica, and a zonation proposal. J. Micropalaeontol. 37, 105–138 (2018).
Benninghoff, W. S. Calculation of pollen and spores density in sediments by addition of exotic pollen in known quantities. Pollen Spores 6, 332–333 (1962).
Harland, R. & Pudsey, C. J. Dinoflagellate cysts from sediment traps deployed in the Bellingshausen, Weddell and Scotia seas, Antarctica. Mar. Micropaleontol. 37, 77–99 (1999).
Prebble, J. G. et al. An expanded modern dinoflagellate cyst dataset for the Southwest Pacific and Southern Hemisphere with environmental associations. Mar. Micropaleontol. 101, 33–48 (2013).
Hartman, J. D., Bijl, P. K. & Sangiorgi, F. A review of the ecological affinities of marine organic microfossils from a Holocene record offshore of Adélie Land (East Antarctica). J. Micropalaeontol. 37, 445–497 (2018).
Zonneveld, K. A. et al. Atlas of modern dinoflagellate cyst distribution based on 2405 data points. Rev. Palaeobot. Palynol. 191, 1–197 (2013).
Warny, S. et al. Palynomorphs from a sediment core reveal a sudden remarkably warm Antarctica during the middle Miocene. Geology 37, 955–958 (2009).
Sangiorgi, F. et al. Southern Ocean warming and Wilkes Land ice sheet retreat during the mid-Miocene. Nat. Commun. 9, 317 (2018).
Niessen, F., Gebhardt, A. C., Kuhn, G., Magens, D. & Monien, D. Porosity and density of the AND-1B sediment core, McMurdo Sound region, Antarctica: Field consolidation enhanced by grounded ice. Geosphere 9, 489–509 (2013).
Cody, R. D., Levy, R. H., Harwood, D. M. & Sadler, P. M. Thinking outside the zone: high-resolution quantitative diatom biochronology for the Antarctic Neogene. Palaeogeogr. Palaeoclimatol. Palaeoecol. 260, 92–121 (2008).
Florindo, F. et al. Paleomagnetism and biostratigraphy of sediments from Southern Ocean ODP Site 744 (southern Kerguelen Plateau): implications for early-to-middle Miocene climate in Antarctica. Global Planet. Change 110, 434–454 (2013).
Crampton, J. S. et al. Southern Ocean phytoplankton turnover in response to stepwise Antarctic cooling over the past 15 million years. Proc. Natl Acad. Sci. USA 113, 6868–6873 (2016).
Scherer, R., Bohaty, S. M. & Harwood, D. M. Oligocene and lower Miocene siliceous microfossil biostratigraphy of Cape Roberts Project Core CRP-2/2A, Victoria Land Basin, Antarctica. Terra Antarct. 7, 417–442 (2000).
Taviani, M. et al. Palaeontological characterisation and analysis of the AND-2A core, ANDRILL Southern McMurdo Sound Project, Antarctica. Terra Antarct. 15, 113–146 (2008).
Farmer, R. K. The Application of Biostratigraphy and Paleoecology at Southern Ocean Drill Sites to Resolve Early to Middle Miocene Paleoclimatic Events MS thesis, Univ. Nebraska-Lincoln (2011).
Meyers, S. R. The evaluation of eccentricity‐related amplitude modulation and bundling in paleoclimate data: An inverse approach for astrochronologic testing and time scale optimization. Paleoceanography 30, 1625–1640 (2015).
Meyers, S. R. Astrochron: An R Package for Astrochronology (2014); http://cran.rproject.org/package=astrochron
Meyers, S. R. Cyclostratigraphy and the problem of astrochronologic testing. Earth Sci. Rev. 190, 190–223 (2019).
Laskar, J. et al. A long-term numerical solution for the insolation quantities of the Earth. Astron. Astrophys. 428, 261–285 (2004).
Taner, M. T. Attributes Revisited. Technical Report (Rock Solid Images, 1992).
Billups, et al. Astronomic calibration of the late Oligocene through early Miocene geomagnetic polarity time scale. Earth Planet. Sci. Lett. 224, 33–44 (2004).
Kochhann, K. G. et al. Eccentricity pacing of eastern equatorial Pacific carbonate dissolution cycles during the Miocene Climatic Optimum. Paleoceanography 31, 1–17 (2016).
Suganuma, Y. et al. 10Be evidence for delayed acquisition of remanent magnetization in marine sediments: Implication for a new age for the Matuyama–Brunhes boundary. Earth Planet. Sci. Lett. 296, 443–450 (2010).
Suganuma, Y. et al. Post-depositional remanent magnetization lock-in for marine sediments deduced from 10Be and paleomagnetic records through the Matuyama–Brunhes boundary. Earth Planet. Sci. Lett. 311, 39–52 (2011).
Roberts, A. P. & Winklhofer, M. Why are geomagnetic excursions not always recorded in sediments? Constraints from post-depositional remanent magnetization lock-in modelling. Earth Planet. Sci. Lett. 227, 345–359 (2004).
Boger, S. D. Antarctica—before and after Gondwana. Gondwana Res. 19, 335–371 (2011).
Siddoway, C. S. in Antarctica: A Keystone in a Changing World (eds Cooper, A., Raymond, C. and the 10th ISAES Editorial Team) 91–114 (The National Academic Press, USA, 2008).
Mukasa, S. B. & Dalziel, I. W. Marie Byrd Land, West Antarctica: Evolution of Gondwana’s Pacific margin constrained by zircon U-Pb geochronology and feldspar common-Pb isotopic compositions. Geol. Soc. Am. Bull. 112, 611–627 (2000).
Weaver, S. D., Adams, C. J., Pankhurst, R. J. & Gibson, I. L. Granites of Edward VII Peninsula, Marie Byrd Land: anorogenic magmatism related to Antarctic-New Zealand rifting. Earth Environ. Sci. Trans. R. Soc. Edinb. 83, 281–290 (1992).
Korhonen, F. J., Saito, S., Brown, M., Siddoway, C. S. & Day, J. M. D. Multiple generations of granite in the Fosdick Mountains, Marie Byrd Land, West Antarctica: implications for polyphase intracrustal differentiation in a continental margin setting. J. Petrol. 51, 627–670 (2010).
Craddock, J. et al. Precise U-Pb zircon ages and geochemistry of Jurassic granites, Ellsworth-Whitmore terrane, central Antarctica. Geol. Soc. Am. Bull. 129, 118–136 (2017).
Pankhurst, R. J., Weaver, S. D., Bradshaw, J. D., Storey, B. C. & Ireland, T. R. Geochronology and geochemistry of pre‐Jurassic superterranes in Marie Byrd Land, Antarctica. J. Geophys. Res. Solid Earth 103, 2529–2547 (1998).
Flowerdew, M. J. et al. Combined U-Pb geochronology and Hf isotope geochemistry of detrital zircons from early Paleozoic sedimentary rocks, Ellsworth-Whitmore Mountains block, Antarctica. Geol. Soc. Am. Bull. 119, 275–288 (2007).
Elliot, D. H. & Fanning, C. M. Detrital zircons from upper Permian and lower Triassic Victoria Group sandstones, Shackleton Glacier region, Antarctica: evidence for multiple sources along the Gondwana plate margin. Gondwana Res. 13, 259–274 (2008).
Elliot, D. H., Fanning, C. M. & Hulett, S. R. Age provinces in the Antarctic craton: Evidence from detrital zircons in Permian strata from the Beardmore Glacier region, Antarctica. Gondwana Res. 28, 152–164 (2015).
Goodge, J. W., Williams, I. S. & Myrow, P. Provenance of Neoproterozoic and lower Paleozoic siliciclastic rocks of the central Ross orogen, Antarctica: Detrital record of rift-, passive-, and active-margin sedimentation. Geol. Soc. Am. Bull. 116, 1253–1279 (2004).
Paulsen, T. S. et al. Detrital mineral ages from the Ross Supergroup, Antarctica: Implications for the Queen Maud terrane and outboard sediment provenance on the Gondwana margin. Gondwana Res. 27, 377–391 (2015).
Paulsen, T. S. et al. Correlation and Late-Stage Deformation of Liv Group Volcanics in the Ross-Delamerian Orogen, Antarctica, from New U-Pb Ages. J. Geol. 126, 307–323 (2018).
Goodge, J. W., Fanning, C. M., Norman, M. D. & Bennett, V. C. Temporal, isotopic and spatial relations of early Paleozoic Gondwana-margin arc magmatism, central Transantarctic Mountains, Antarctica. J. Petrol. 53, 2027–2065 (2012).
Paulsen, T. S. et al. Age and significance of ‘outboard’ high-grade metamorphics and intrusives of the Ross orogen, Antarctica. Gondwana Res. 24, 349–358 (2013).
Rowell, A. J. et al. An active Neoproterozoic margin: evidence from the Skelton Glacier area, Transantarctic Mountains. J. Geol. Soc. Lond. 150, 677–682 (1993).
Encarnación, J. & Grunow, A. Changing magmatic and tectonic styles along the paleo‐Pacific margin of Gondwana and the onset of early Paleozoic magmatism in Antarctica. Tectonics 15, 1325–1341 (1996).
Goodge, J. W., Hansen, V. L., Peacock, S. M., Smith, B. K. & Walker, N. W. Kinematic evolution of the Miller Range shear zone, central Transantarctic Mountains, Antarctica, and implications for Neoproterozoic to early Paleozoic tectonics of the East Antarctic margin of Gondwana. Tectonics 12, 1460–1478 (1993).
Van Schmus, W. R., McKenna, L. W., Gonzales, D. A., Fetter, A. H. & Rowell, A. J. U-Pb geochronology of parts of the Pensacola, Thiel, and Queen Maud Mountains, Antarctica. In The Antarctic Region: Geological Evolution and Processes (ed. Ricci, C. A.) 187–200 (Terra Antartica Publication, 1995).
Stump, E. The Ross Orogen of the Transantarctic Mountains (Cambridge Univ. Press, 1995).
Martin, A. P., Price, R. C., Cooper, A. F. & McCammon, C. A. Petrogenesis of the rifted southern Victoria Land lithospheric mantle, Antarctica, inferred from petrography, geochemistry, thermobarometry and oxybarometry of peridotite and pyroxenite xenoliths from the Mount Morning eruptive centre. J. Petrol. 56, 193–226 (2015).
Goodge, J. W., Myrow, P., Williams, I. S. & Bowring, S. A. Age and provenance of the Beardmore Group, Antarctica: constraints on Rodinia supercontinent breakup. J. Geol. 110, 393–406 (2002).
Stump, E., Gehrels, G., Talarico, F. M. & Carosi, R. Constraints from detrital zircon geochronology on the early deformation of the Ross orogen, Transantarctic Mountains, Antarctica. In Antarctica: A Keystone in a Changing World – Online Proceedings of the 10th ISAES (eds Cooper, A. K. et al.) Extended Abstract 166 (USGS Open-File Report 2007-1047, 2007).
Cooper, A. F., Maas, R., Scott, J. M. & Barber, A. J. Dating of volcanism and sedimentation in the Skelton Group, Transantarctic Mountains: implications for the Rodinia-Gondwana transition in southern Victoria Land, Antarctica. Geol. Soc. Am. Bull. 123, 681–702 (2011).
Goodge, J. W., Fanning, C. M. & Bennett, V. C. U–Pb evidence of ~1.7 Ga crustal tectonism during the Nimrod Orogeny in the Transantarctic Mountains, Antarctica: implications for Proterozoic plate reconstructions. Precambr. Res. 112, 261–288 (2001).
Goodge, J. W. & Fanning, C. M. Mesoarchean and Paleoproterozoic history of the Nimrod Complex, central Transantarctic Mountains, Antarctica: stratigraphic revisions and relation to the Mawson Continent in East Gondwana. Precambr. Res. 285, 242–271 (2016).
Veevers, J. J. & Saeed, A. Age and composition of Antarctic bedrock reflected by detrital zircons, erratics, and recycled microfossils in the Prydz Bay–Wilkes Land–Ross Sea–Marie Byrd Land sector (70–240 E). Gondwana Res. 20, 710–738 (2011).
Goodge, J. W. & Fanning, C. M. 2.5 by of punctuated Earth history as recorded in a single rock. Geology 27, 1007–1010 (1999).
Grindley, G. W., McGregor, V. R. & Walcott, R. I. In Antarctic Geology: Proceedings of the First International Symposium on Antarctic Geology (ed. Adie, R. J.) 206–219 (North Holland, 1964).
Laird, M. G. in The Geology of Antarctica (ed Tingey R. J.) 74–119 (Oxford Univ. Press, 1991).
Goodge, J. W. & Finn, C. A. Glimpses of East Antarctica: Aeromagnetic and satellite magnetic view from the central Transantarctic Mountains of East Antarctica. J. Geophys. Res. Solid Earth https://doi.org/10.1029/2009JB006890 (2010).
Goodge, J. W. & Fanning, C. M. Composition and age of the East Antarctic Shield in eastern Wilkes Land determined by proxy from Oligocene-Pleistocene glaciomarine sediment and Beacon Supergroup sandstones, Antarctica. Geol. Soc. Am. Bull. 122, 1135–1159 (2010).
Gunn, B. M. & Warren, G. Geology of Victoria Land between the Mawson and Mulock Glaciers, Antarctica. New Zea. Geol. Bull. 71, 157 (1962).
Encarnación, J., Rowell, A. J. & Grunow, A. M. A U-Pb age for the Cambrian Taylor Formation, Antarctica: Implications for the Cambrian time scale. J. Geol. 107, 497–504 (1999).
Wareham, C. D., Stump, E., Storey, B. C., Millar, I. L. & Riley, T. R. Petrogenesis of the Cambrian Liv Group. A bimodal volcanic rock suite from the Ross orogen, Transantarctic Mountains. Geol. Soc. Am. Bull. 113, 360–372 (2001).
Elliot, D. H., Larsen, D., Fanning, C. M., Fleming, T. H. & Vervoort, J. D. The Lower Jurassic Hanson Formation of the Transantarctic Mountains: implications for the Antarctic sector of the Gondwana plate margin. Geol. Mag. 154, 777–803 (2016).
Elliot, D. H., Fanning, C. M., Isbell, J. L. & Hulett, S. R. W. The Permo-Triassic Gondwana sequence, central Transantarctic Mountains, Antarctica: Zircon geochronology, provenance, and basin evolution. Geosphere 13, 155–178 (2017).
Elsner, M., Schöner, R., Gerdes, A. & Gaupp, R. Reconstruction of the early Mesozoic plate margin of Gondwana by U–Pb ages of detrital zircons from northern Victoria Land, Antarctica. Geol. Soc. Lond. Spec. Publ. 383, 211–232 (2013).
Paulsen, T., Deering, C., Sliwinski, J., Bachmann, O. & Guillong, M. New detrital zircon age and trace element evidence for 1450 Ma igneous zircon sources in East Antarctica. Precambr. Res. 300, 53–58 (2017).
Zurli, L. et al. Detrital zircons from Late Paleozoic Ice Age sequences in Victoria Land (Antarctica): New constraints on the glaciation of southern Gondwana. Geol. Soc. Am. Bull. (2021).
Welke, B. et al. Applications of detrital geochronology and thermochronology from glacial deposits to the Paleozoic and Mesozoic thermal history of the Ross Embayment, Antarctica. Geochem. Geophys. Geosyst. 17, 2762–2780 (2016).
Vogel, M. B., Ireland, T. R. & Weaver, S. D. The multistage history of the Queen Maud Batholith, La Gorce Mountains, central Transantarctic Mountains. In Proc. 8th Int. Symp. Antarctic Earth Sciences Wellington 1999 (eds Gamble, J. A., Skinner, D. N. B., Henrys, S. A.) 153–159 (Royal Society of New Zealand, 2002).
Gootee, B. & Stump, E. in Antarctica (eds Fütterer D. K., Damaske D., Kleinschmidt G., Miller H. & Tessensohn F.) 191–194 (Springer, 2006).
Barrett, P. J. in Geology of Antarctica (ed. Tingey, R. J.) 120–152 (Clarendon Press, 1991).
Ferraccioli, F., Armadillo, E., Jordan, T., Bozzo, E. & Corr, H. Aeromagnetic exploration over the East Antarctic Ice Sheet: a new view of the Wilkes Subglacial Basin. Tectonophysics 478, 62–77 (2009).
Paxman, G. J. et al. Geology and Geomorphology of the Pensacola‐Pole Basin, East Antarctica. Geochem. Geophys. Geosyst. 20, 2786–2807 (2019).
Elliot, D. H. The Hanson Formation: a new stratigraphical unit in the Transantarctic Mountains, Antarctica. Antarct. Sci. 8, 389–394 (1996).
Elliot, D. H. & Fleming, T. H. Occurrence and dispersal of magmas in the Jurassic Ferrar large igneous province, Antarctica. Gondwana Res. 7, 223–237 (2004).
Burgess, S. D., Bowring, S. A., Fleming, T. H. & Elliot, D. H. High-precision geochronology links the Ferrar large igneous province with early-Jurassic ocean anoxia and biotic crisis. Earth Planet. Sci. Lett. 415, 90–99 (2015).
Encarnación, J., Fleming, T. H., Elliot, D. H. & Eales, H. V. Synchronous emplacement of Ferrar and Karoo dolerites and the early breakup of Gondwana. Geology 24, 535–538 (1996).
Cook, C. P. et al. Glacial erosion of East Antarctica in the Pliocene: A comparative study of multiple marine sediment provenance tracers. Chem. Geol. 466, 199–218 (2017).
Adams, C. J. Geochronological studies of the Swanson Formation of Marie Byrd Land, West Antarctica, and correlation with northern Victoria Land, East Antarctica, and South Island, New Zealand. N. Z. J. Geol. Geophys. 29, 345–358 (1986).
Yakymchuk, C. et al. Anatectic Reworking and Differentiation of Continental Crust Along the Active Margin of Gondwana: A Zircon Hf–O Perspective from West Antarctica (Geological Society London, Special Publication 383, 2013); https://doi.org/10.1144/SP383.7
Yakymchuk, C. et al. Paleozoic evolution of western Marie Byrd Land, Antarctica. Bull. Geol. Soc. Am. 127, 1464–1484 (2015).
Simões Pereira, P. et al. The geochemical and mineralogical fingerprint of West Antarctica’s weak underbelly: Pine Island and Thwaites glaciers. Chem. Geol. 550, 119649 (2020).
Adams, C. J. Geochronology of granite terranes in the Ford Ranges, Marie Byrd Land, West Antarctica. N. Z. J. Geol. Geophys. 30, 51–72 (1987).
LeMasurier, W. E. et al. Volcanoes of the Antarctic Plate and Southern Ocean Vol. 48 (American Geophysical Union, 1990).
Licht, K. J. et al. Evidence for extending anomalous Miocene volcanism at the edge of the East Antarctic craton. Geophys. Res. Lett. 45, 3009–3016 (2018).
Brodie, J. W. A shallow shelf around Franklin Island in the Ross Sea, Antarctica. N. Z. J. Geol. Geophys. 2, 108–119 (1959).
Lawver, L., Lee, J., Kim, Y. & Davey, F. Flat-topped mounds in western Ross Sea: Carbonate mounds or subglacial volcanic features? Geosphere 8, 645–653 (2012).
Di Vincenzo, G., Bracciali, L., Del Carlo, P., Panter, K. & Rocchi, S. 40Ar–39Ar dating of volcanogenic products from the AND-2A core (ANDRILL Southern McMurdo Sound Project, Antarctica): correlations with the Erebus Volcanic Province and implications for the age model of the core. Bull. Volcanol. 72, 487–505 (2010).
Panter, K. S. et al. Melt origin across a rifted continental margin: a case for subduction-related metasomatic agents in the lithospheric source of alkaline basalt, NW Ross Sea, Antarctica. J. Petrol. 59, 517–558 (2018).
McIntosh, W. C. 40Ar/39Ar geochronology of tephra and volcanic clasts in CRP-2A, Victoria Land Basin, Antarctica. Terra Antarct. 7, 621–630 (2000).
LeMasurier, W. E. & Rocchi, S. Terrestrial record of post‐Eocene climate history in Marie Byrd Land, West Antarctica. Geogr. Ann., Ser. A 87, 51–66 (2005).
Rocchi, S., LeMasurier, W. E. & Di Vincenzo, G. Oligocene to Holocene erosion and glacial history in Marie Byrd Land, West Antarctica, inferred from exhumation of the Dorrel Rock intrusive complex and from volcano morphologies. Bull. Geol. Soc. Am. 118, 991–1005 (2006).
LeMasurier, W. Shield volcanoes of Marie Byrd Land, West Antarctic rift: oceanic island similarities, continental signature, and tectonic controls. Bull. Volcanol. 75, 726 (2013).
Behrendt, J. C. et al. Geophysical studies of the West Antarctic rift system. Tectonics 10, 1257–1273 (1991).
McDougall, I. & Harrison, T. M. Geochronology and Thermochronology by the 40Ar/39Ar Method (Oxford Univ. Press, 1999).
Cherniak, D. J. & Watson, E. B. Pb diffusion in zircon. Chem. Geol. 172, 5–24 (2001).
Morrison, A. D. & Reay, A. Geochemistry of Ferrar Dolerite sills and dikes at Terra Cotta Mountain, south Victoria Land, Antarctica. Antarct. Sci. 7, 73–85 (1995).
Cox, S. C., Turnbull, I. M., Isaac, M. J., Townsend, D. B. & Smith Lyttle, B. Geology of Southern Victoria Land, Antarctica (Institute of Geological & Nuclear, 2012).
Ford, A. B. Stratigraphy of the Layered Gabbroic Dufek Intrusion, Antarctica (US Govt. Print. Off., 1976; http://pubs.er.usgs.gov/publication/b1405D
Borg, S. G., Depaolo, D. J. & Smith, B. M. Isotopic structure and tectonics of the central Transantarctic Mountains. J. Geophys. Res. Solid Earth 95, 6647–6667 (1990).
Cox, S. C., Parkinson, D. L., Allibone, A. H. & Cooper, A. F. Isotopic character of Cambro‐Ordovician plutonism, southern Victoria Land, Antarctica. N. Z. J. Geol. Geophys. 43, 501–520 (2000).
Gunner, J. Isotopic and Geochemical Studies of the Pre-Devonian Basement Complex, Beardmore Glacier Region, Antarctica (Ohio State Univ. Institute of Polar Studies Report No. 41, 1976).
Roy, M., van de Flierdt, T., Hemming, S. R. & Goldstein, S. L. 40Ar/39Ar ages of hornblende grains and bulk Sm/Nd isotopes of circum-Antarctic glacio-marine sediments: Implications for sediment provenance in the Southern Ocean. Chem. Geol. 244, 507–519 (2007).
Behrendt, J. C. The aeromagnetic method as a tool to identify Cenozoic magmatism in the West Antarctic Rift System beneath the West Antarctic Ice Sheet—A review; Thiel subglacial volcano as possible source of the ash layer in the WAISCORE. Tectonophysics 585, 124–136 (2013).
Lough, A. C. et al. Seismic detection of an active subglacial magmatic complex in Marie Byrd Land, Antarctica. Nat. Geosci. 6, 1031–1035 (2013).
Schroeder, D. M., Blankenship, D. D., Young, D. A. & Quartini, E. Evidence for elevated and spatially variable geothermal flux beneath the West Antarctic Ice Sheet. Proc. Natl Acad. Sci. USA 111, 9070–9072 (2014).
Ehrmann, W. U., Melles, M., Kuhn, G. & Grobe, H. Significance of clay mineral assemblages in the Antarctic Ocean. Mar. Geol. 107, 249–273 (1992).
Fagel, N. Clay minerals, deep circulation and climate. Proxies Late Cenozoic Paleoceanogr. 1, 139–184 (2007).
Kristoffersen, Y., Strand, K., Vorren, T., Harwood, D. & Webb, P. Pilot shallow drilling on the continental shelf, Dronning Maud Land, Antarctica. J. Antarct. Sci. 4, 463–470 (2000).
Ehrmann, W. et al. Provenance changes between recent and glacial-time sediments in the Amundsen Sea embayment, West Antarctica: clay mineral assemblage evidence. Antarct. Sci. 23, 471–486 (2011).
Hillenbrand, C. D., Grobe, H., Diekmann, B., Kuhn, G. & Fütterer, D. K. Distribution of clay minerals and proxies for productivity in surface sediments of the Bellingshausen and Amundsen seas (West Antarctica)–Relation to modern environmental conditions. Mar. Geol. 193, 253–271 (2003).
Klages, J. P. et al. Temperate rainforests near the South Pole during peak Cretaceous warmth. Nature 580, 81–86 (2020).
Zonneveld, K. A. F., Bockelmann, F. & Holzwarth, U. Selective preservation of organic-walled dinoflagellate cysts as a tool to quantify past net primary production and bottom water oxygen concentrations. Mar. Geol. 237, 109–126 (2007).
Prebble, J. G., Hannah, M. J. & Barrett, P. J. Changing Oligocene climate recorded by palynomorphs from two glacio-eustatic sedimentary cycles, Cape Roberts Project, Victoria Land Basin, Antarctica. Palaeogeogr. Palaeoclimatol. Palaeoecol. 231, 58–70 (2006).
Kulhanek, D. K. et al. Revised chronostratigraphy of DSDP Site 270 and late Oligocene to early Miocene paleoecology of the Ross Sea sector of Antarctica. Global Planet. Change 178, 46–64 (2019).
Feakins, S., Warny, S. & Lee, J. E. Hydrologic cycling over Antarctica during the middle Miocene warming. Nat. Geosci. 5, 557–560 (2012).
De Santis, L., Prato, S., Brancolini, G., Lovo, M. & Torelli, L. The Eastern Ross Sea continental shelf during the Cenozoic: implications for the West Antarctic ice sheet development. Global Planet. Change 23, 173–196 (1999).
Ford, A. B. & Barrett, P. J. Basement rocks of the south-central Ross Sea, Site 270, DSDP Leg 28. Initial Rep. Deep Sea Drill. Proj. 28, 861–868 (1975).
Goldich, S. S., Treves, S. B., Suhr, N. H. & Stuckless, J. S. Geochemistry of the Cenozoic volcanic rocks of Ross Island and vicinity, Antarctica. J. Geol. 83, 415–435 (1975).
Tulaczyk, S., Kamb, B., Scherer, R. P. & Engelhardt, H. F. Sedimentary processes at the base of a West Antarctic ice stream; constraints from textural and compositional properties of subglacial debris. J. Sediment. Res. 68, 487–496 (1998).
Rosenqvist, I. T. Origin and mineralogy glacial and interglacial clays of southern Norway. Clays Clay Miner. 23, 153–159 (1975).
Blum, J. D. & Erel, Y. Rb/ Sr isotope systematics of a granitic soil chronosequence: The importance of biotite weathering. Geochim. Cosmochim. Acta 61, 3193–3204 (1997).
Eisenhauer, A. et al. Grain size separation and sediment mixing in Arctic Ocean sediments: evidence from the strontium isotope systematic. Chem. Geol. 158, 173–188 (1999).
Haran, T. MODIS Mosaic of Antarctica 2008–2009 (MOA2009) Image Map, Version 1. Boulder, Colorado, USA., NASA National Snow and Ice Data Center Distributed Active Archive Center, https://doi.org/10.7265/N5KP8037 (2014).
This research used data and samples provided by the International Ocean Discovery Program (IODP), which is sponsored by the US National Science Foundation (NSF) and participating countries under the management of Joint Oceanographic Institutions. J.W.M. was supported by a NERC DTP studentship (grant number NE/L002515/1). Neodymium and Sr isotope analysis and U–Pb dating of detrital zircons was funded through NERC UK IODP grant NE/R018219/1. Clast counts performed by L.Z., F.T. and M.P. and the participation of L.D. and F.C. was funded by the Italian National Antarctic Research Program (PNRA, Programma Nazionale Ricerche in Antartide), grant numbers PNRA18-00233, PNRA16-00016 and PNRA18-00002. R.M.M. was supported by Royal Society Te Apārangi Marsden Fund (18-VUW-089). R.M.M., J.G.P. and R.L. were supported by the New Zealand Ministry for Business Innovation and Employment grant ANTA1801. P.V. was partially funded by NERC Standard Grant NE/T001518/1. L.F.P. has been funded by the European Union’s Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement no. 792773 WAMSISE. T.E.v.P. has been funded by NERC grants NE/R018235/1 and NE/T012285/1. D.K.K. was supported by the IODP JOIDES Resolution Science Operator and National Science Foundation (grant numbers OCE-1326927 and OPP-2000995). A.E.S. and I.B. were supported by the US Science Support Program. Southern Transantarctic Mountain rock samples for Nd and Sr isotope analysis were provided by the Polar Rock Repository with support from the National Science Foundation, under Cooperative Agreement OPP-1643713. We thank B. Coles, K. Kreissig and P. Simões Pereira for technical support. We also thank the numerous scientists who collected invaluable site survey data and developed the proposals and hypotheses that ultimately led to IODP Expedition 374. Expedition 374 was conducted under Antarctic Conservation Act Permit Number: ACA 2018-027 (permit holder: Bradford Clement, JRSO, IODP, TAMU, College Station, TX 77845).
The authors declare no competing interests.
Peer review information Nature thanks Patrick Blaser, Maria Fernanda Sanchez-Goni, Kenneth Miller and the other, anonymous, reviewer(s) for their contribution to the peer review of this work. Peer reviewer reports are available.
Publisher’s note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
Extended data figures and tables
From left to right are: depth (metres below sea floor), core number, core recovery (black = recovered), inclination before and after 10 and 20 mT demagnetisation (black, blue and red points, successively), and corresponding polarity interpretations (black = normal, white = reversed, grey = no interpretation). Note that the polarity interpretations have been simplified compared to those in the cruise report26, with small uncertainties related to core gaps removed. Note Site U1521 is in the Southern Hemisphere. The geomagnetic polarity timescale49 is shown across the top of the plot. The orange shaded regions indicate uncertainties in our age model and the dashed line marks an alternative line of correlation for Sequence 3. The blue line indicates the age model for Sequence 2 based on our astrochronological analyses, with the light blue shading indicating the ~20 kyr uncertainty associated with the phase relationship between clast abundances and obliquity. This astrochronological anchoring agrees closely with linear interpolations between magnetostratigraphic tie points (black line).
Extended Data Fig. 2 Selected palynological counts compared to strontium and neodymium isotope data.
Palynological data are reported as percentages (crosses) and counts/gram (circles). The blue shaded area represents Sequence 2, which is interpreted as consisting of sediments with a West Antarctic provenance. Error bars indicate a 95% confidence interval48.
The blue shaded area highlights Sequence 2, which is interpreted to consist of sediments with a West Antarctic provenance. a) Core lithology. b) Chronostratigraphic sequences. c) Clast abundance. d) Percentages of different clast lithologies. e) Ratio between dolerite and total number of clasts (red) and volcanic rocks and total number of clasts (green), with 95% confidence interval shown as pale shading48. f) Clay mineral abundances.
Extended Data Fig. 4 Map of approximate ɛNd values in rocks and offshore sediments from around the Ross Sea embayment.
Epsilon Nd values are overlain on MODIS imagery200 and the BedMachine Antarctica V1 modern bed topography43,44, with the MEaSUREs grounding line and ice sheet margin shown45,46. The approximate boundary between West and East Antarctic lithosphere is shown using a white dashed line47. Modern/late Holocene and terrestrial till samples are represented by circles with the same colour bar28,30,55. Although ice flow patterns have changed since their deposition, Last Glacial Maximum tills in offshore sediments are also plotted as squares to improve spatial coverage28. Individual samples and references are reported in Supplementary Table 1. The bedrock map was produced by Kriging between sample locations within a group, then masking to the outcrop area. Beacon and Ferrar Group (Fig. 1) rocks are often not differentiated in geological mapping, but are roughly equal volumetrically136, with the uppermost Beacon Supergroup formations having a Ferrar-like isotopic signature139. We hence assume a 60% Ferrar, 40% Beacon mixture is representative.
The stratigraphic log (a) is displayed alongside the percentage of reworked dinocysts (b), basalt clast fraction (c), relative abundance of smectite (d), Nd isotope data (e) and Fe/Ti ratios determined by X-ray fluorescence scanning (f).
This file contains information on the lithologies at IODP Site U1521, before summarising the rock types and tectonic history of the Ross Sea sector. We also provide a more detailed discussion of our sediment provenance datasets, plus suggested provenance interpretations for other lithological units. Additional supplementary methods are also described.
Compiled Nd and Sr isotope data from literature sources are presented in this excel spreadsheet. These data were used to interpret the isotope ratios measured at Site U1521 and to create Extended Data Figures 4 and 5. References are given in a separate tab.
About this article
Cite this article
Marschalek, J.W., Zurli, L., Talarico, F. et al. A large West Antarctic Ice Sheet explains early Neogene sea-level amplitude. Nature 600, 450–455 (2021). https://doi.org/10.1038/s41586-021-04148-0
This article is cited by
Nature Geoscience (2022)