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Sequence Stratigraphy Of The Andrill And-2a Drillcore, Antarctica: A Long-Term, Ice-Proximal Record Of Early To Mid-Miocene Climate, Sea-Level And Glacial Dynamism, Christopher R. Fielding, Greg H. Browne, Brad Field, F. Florindo, D. M. Harwood, L. A. Krissek, Richard Levy, K. Panter, Sandra Passchier, Stephen F. Pekar Jul 2018

Sequence Stratigraphy Of The Andrill And-2a Drillcore, Antarctica: A Long-Term, Ice-Proximal Record Of Early To Mid-Miocene Climate, Sea-Level And Glacial Dynamism, Christopher R. Fielding, Greg H. Browne, Brad Field, F. Florindo, D. M. Harwood, L. A. Krissek, Richard Levy, K. Panter, Sandra Passchier, Stephen F. Pekar

Sandra Passchier

Present understanding of Antarctic climate change during the Early to Mid-Miocene, including major cycles of glacial expansion and contraction, relies in large part on stable isotope proxies from deep sea core drilling. Here, we summarize the lithostratigraphy of the ANDRILL Southern McMurdo Sound Project drillcore AND-2A. This core offers a hitherto unavailable ice-proximal stratigraphic archive from a high-accommodation continental margin setting, and provides clear evidence of repeated fluctuations in climate, ice expansion/contraction and attendant sea-level change over the period c. 20.2–14.2 Ma, with a more fragmentary record of Late Miocene and Pliocene time. The core is divided into seventy-four high-frequency …


Early Miocene Antarctic Glacial History: New Insights From Heavy Mineral Analysis From Andrill And–2a Drill Core Sediments, Francesco Iacoviello, Giovanna Giorgetti, Isabella Turbanti Memmi, Sandra Passchier Jul 2018

Early Miocene Antarctic Glacial History: New Insights From Heavy Mineral Analysis From Andrill And–2a Drill Core Sediments, Francesco Iacoviello, Giovanna Giorgetti, Isabella Turbanti Memmi, Sandra Passchier

Sandra Passchier

The present study deals with heavy mineral analysis of late Early Miocene marine sediments recovered in the McMurdo Sound region (Ross Sea, Antarctica) during the ANDRILL— SMS Project in 2007. The main objective is to investigate how heavy mineral assemblages reflect different source rocks and hence different provenance areas. These data contribute to a better understanding of East Antarctica ice dynamics in the Ross Sea sector during the Early Miocene (17.6–20.2 Ma), a time of long-term global warming and sea level rise. The AND-2A drill core recovered several stratigraphic intervals that span from Early Miocene to Pleistocene and it collected …


Sedimentology And Stratigraphy Of The And-2a Core, Andrill Southern Mcmurdo Sound Project, Antarctica, Christopher R. Fielding, C. B. Atkins, K. N. Bassett, G. H. Browne, G. B. Dunbar, B. D. Field, Tracy D. Frank, L. A. Krissek, K. S. Panter, S. Passchier, S. F. Pekar, S. Sandroni, F. Talarico Jul 2018

Sedimentology And Stratigraphy Of The And-2a Core, Andrill Southern Mcmurdo Sound Project, Antarctica, Christopher R. Fielding, C. B. Atkins, K. N. Bassett, G. H. Browne, G. B. Dunbar, B. D. Field, Tracy D. Frank, L. A. Krissek, K. S. Panter, S. Passchier, S. F. Pekar, S. Sandroni, F. Talarico

Sandra Passchier

During the 2007 – 2008 austral spring season, the ANDRILL Southern McMurdo Sound Project recovered a core 1138 metres long (AND-2A) from a location in the southern McMurdo Sound near the Dailey Islands. This core contains a range of lithologies, including various types of terrigenous clastic diamictite, conglomerate and breccia, sandstone and mudrocks, volcanic lava, pyroclastic and reworked volcanic sedimentary rocks, and diatomite. The succession is divided into fourteen lithostratigraphic units (LSUs), two of which (LSUs 1 and 8) are further subdivided into three and four sub-units, respectively, based on changes in abundance of lithologies. Thirteen lithofacies are recognized, ranging …


Orbitally Induced Oscillations In The East Antarctic Ice Sheet At The Oligocene/Miocene Boundary, Tim R. Naish, Ken J. Woolfe, Peter J. Barrett, Gary S. Wilson, Cliff Atkins, Steven M. Bohaty, Christian J. Bücker, Michele Claps, Fred J. Davey, Gavin B. Dunbar, Alistair G. Dunn, Christopher R. Fielding, Fabio Florindo, Michael J. Hannah, David M. Harwood, Stuart A. Henrys, Lawrence A. Krissek, Mark Lavelle, Jaap Van Der Meer, William C. Mcintosh, Frank Niessen, Sandra Passchier, Ross D. Powell, Andrew P. Roberts, Leonardo Sagnotti, Reed P. Scherer, C. Percy Strong, Franco Talarico, Kenneth L. Verosub, Giuliana Villa, David K. Watkins, Peter-N. Webb, Thomas Wonik Jul 2018

Orbitally Induced Oscillations In The East Antarctic Ice Sheet At The Oligocene/Miocene Boundary, Tim R. Naish, Ken J. Woolfe, Peter J. Barrett, Gary S. Wilson, Cliff Atkins, Steven M. Bohaty, Christian J. Bücker, Michele Claps, Fred J. Davey, Gavin B. Dunbar, Alistair G. Dunn, Christopher R. Fielding, Fabio Florindo, Michael J. Hannah, David M. Harwood, Stuart A. Henrys, Lawrence A. Krissek, Mark Lavelle, Jaap Van Der Meer, William C. Mcintosh, Frank Niessen, Sandra Passchier, Ross D. Powell, Andrew P. Roberts, Leonardo Sagnotti, Reed P. Scherer, C. Percy Strong, Franco Talarico, Kenneth L. Verosub, Giuliana Villa, David K. Watkins, Peter-N. Webb, Thomas Wonik

Sandra Passchier

Between 34 and 15 million years (Myr) ago, when planetary temperatures were 3-4°C warmer than at present and atmospheric CO2 concentrations were twice as high as today, the Antarctic ice sheets may have been unstable. Oxygen isotope records from deep-sea sediment cores suggest that during this time fluctuations in global temperatures and high-latitude continental ice volumes were influenced by orbital cycles. But it has hitherto not been possible to calibrate the inferred changes in ice volume with direct evidence for oscillations of the Antarctic ice sheets. Here we present sediment data from shallow marine cores in the western Ross …