Sandra Passchier

• Ph.D. Geological Sciences
• Professor (Full) at Montclair State University

[1] Few high-latitude terrestrial records document the timing and nature of the Cenozoic “Greenhouse” to “Icehouse” transition. Here we exploit the bulk geochemistry of marine siliciclastic sediments from drill cores on Antarctica's continental margin to extract a unique semiquantitative temperature and precipitation record for Eocene to mid-Miocen...

We investigate the stability of the East Antarctic Ice Sheet (EAIS) on the Wilkes Land continental margin, Antarctica, utilizing a high-resolution record of ice-rafted debris (IRD) mass accumulation rates (MAR) from Integrated Ocean Drilling Program (IODP) Site U1359. The relationship between orbital variations in the IRD record and climate drivers...

Earth's current icehouse phase began ?34 m.y. ago with the onset of major Antarctic glaciation at the Eocene-Oligocene transition. Changes in ocean circulation and a decline in atmospheric greenhouse gas levels were associated with stepwise cooling and ice growth at southern high latitudes. The Antarctic cryosphere plays a critical role in the ocea...

In the Southern Ocean, unconstrained Westerlies allow for intense mixing between deep waters and the atmosphere. How this system interacts with Antarctic ice sheets and the global ocean circulation is poorly understood due to a paucity of data. The poor abundance and preservation of foraminiferal carbonate in ice-proximal sediments is a major chall...

The rapid retreat of the Baltic Ice Stream and the development of the Baltic Ice Lake is assessed using data from sediment cores retrieved from three sub-basins in the southern Baltic Sea. Hydraulic piston coring by the International Ocean Discovery Program (IODP) recovered for the first time intact glacial lake sequences overlying diamictons and o...

The greenhouse to icehouse transition at the Eocene-Oligocene boundary (34 Ma) marked the appearance of continental-scale glaciation in Antarctica. The material recovered from Ocean Drilling Program Site 696 is the only record spanning this major climatic shift in the Weddell Sea region. Using scanning electron microscopy, quartz microtextures in 1...

The Eocene-Oligocene Transition at c. 34 million years ago (Ma) marked the global change from greenhouse to icehouse and the establishment of the East Antarctic Ice Sheet (EAIS). How the ice-sheet behaviour changed during interglacials across this climate transition is poorly understood. We analysed major, trace and rare earth elemental data of lat...

The Eocene‐Oligocene Transition (EOT) at ∼34 Ma marked a climatic shift from greenhouse to icehouse conditions, toward long‐lasting lower global temperatures and a continental ice sheet in the Antarctic. We report on sedimentological and inorganic geochemical results across the EOT at Ocean Drilling Program (ODP) Site 696 in the Weddell Sea, within...

On high‐latitude continental margins sediment is supplied from land to the deep sea through a variety of processes, including iceberg and sea‐ice rafting, and bottom current transport. The accurate reconstruction of sediment fluxes from these sources through time is important in palaeoclimate reconstructions. The goal of this study was to assess a...

Plain Language Summary Collapses of the West Antarctic Ice Sheet (WAIS) during past warm times are suggested to begin in the Amundsen Sea sector. During a drilling expedition of the International Ocean Discovery Program (IODP), deep‐sea sediments were retrieved from the Amundsen Sea. These sediment cores contain records of colder and warmer periods...

The Eocene‐Oligocene transition (EOT) marks the onset of Antarctic glaciation at 33.7 Ma. Although the benthic oxygen isotope record defines the major continental ice sheet expansion, recent sedimentary and geochemical evidence suggests the presence of earlier ephemeral ice sheets. Sediment cores from Ocean Drilling Program Legs 119 and 188 in Pryd...

This paper presents an age–depth model based on an ultra‐high‐resolution, 80‐m‐thick sedimentary succession from a marine continental shelf basin, the Kattegat. This is an area of dynamic deglaciation of the Fennoscandian Ice Sheet during the Late Pleistocene. The Kattegat is also a transitional area between the saline North Sea and the brackish Ba...

The Lambert Glacier-Amery Ice Shelf system (LGAISS) is the largest outlet glacier system in East Antarctica but its response to past climate variability is poorly constrained. In this study, we explore its dynamics over the last ∼520 thousand years using new high-resolution sedimentary records retrieved off Prydz Bay. Episodic occurrences of iceber...

Heavy minerals are typically rare but important components of siliciclastic sediments and rocks. Their abundance, proportions, and variability carry valuable information on source rocks, climatic, environmental and transport conditions between source to sink, and diagenetic processes. They are important for practical purposes such as prospecting fo...

Soil anthropogenic contaminants can limit enzymatic nutrient mineralization, either by direct regulation or via impacts on the microbial community, thus affecting plant growth in agricultural and non-agricultural soils. The impact on phosphatase activity of mixing two contaminated, post-industrial rail yard soils was investigated; one was vegetated...

During the 2007 ANtarctic geological DRILLing (ANDRILL) campaign in the Ross Sea, Antarctica, the AND‐2A core was recovered through a stratigraphic succession spanning 1,138.54 m of Neogene sedimentary rocks that include an expanded early to middle Miocene sequence. The study reported here focuses on the magnetic properties of the interval from 778...

Along glaciated margins, ratios of meteoric cosmogenic beryllium-10, ¹⁰Be, normalized to its stable isotope, ⁹Be, reflect an environmental signal, driven ultimately by climatic change. We explore the application of this isotopic pair as a proxy for East Antarctic Ice Sheet dynamics. We analyze ¹⁰Be/⁹Be in middle Pliocene glaciomarine sediments offs...

The original version of this Article contained an error in the spelling of the author Florence Colleoni, which was incorrectly given as Florence Colloni. This has been corrected in both the PDF and HTML versions of the Article.

Understanding how the Antarctic ice sheet will respond to global warming relies on knowl-edge of how it has behaved in the past. The use of numerical models, the only means to quantitatively predict the future, is hindered by limitations to topographic data both now and in the past, and in knowledge of how subsurface oceanic, glaciological and hydr...

The lowest 501 m (~1139-638 m) of the AND-2A core from southern Mc- Murdo Sound is the most detailed and complete record of early Miocene sediments in Antarctica and indicates substantial variability in Antarctic ice sheet activity during early Miocene time. There are two main pulses of diamictite accumulation recorded in the core, and three signif...

Trough mouth fans (TMFs) are sediment depocentres that form along high-latitude continental margins at the mouths of some cross-shelf troughs. They reflect the dynamics of past ice sheets over multiple glacial cycles and processes operating on (formerly) glaciated continental shelves and slopes, such as erosion, reworking, transport and deposition....

The impact of high-latitude physical processes on the sedimentary geology of a passive continental margin is addressed using a sediment record from the Wilkes Land margin of Antarctica. We present sequence stratigraphic models based on analytical data and genetic interpretations of sedimentary facies assemblages observed in drill cores collected by...

Observations and model experiments highlight the importance of ocean heat in forcing ice sheet retreat during the present and geological past, but past ocean temperature data are virtually missing in ice sheet proximal locations. Here we document paleoceanographic conditions and the (in)stability of the Wilkes Land subglacial basin (East Antarctica...

The impact of high latitude physical processes on the sedimentary geology of a 7 passive continental margin is addressed here using a sediment record from the Wilkes Land 8 margin of Antarctica. We present sequence stratigraphic models based on analytical data and 9 genetic interpretations of sedimentary facies assemblages observed in drill cores c...

The East Antarctic ice sheet underwent a major expansion during the Mid-Miocene Climate Transition, around 14 Ma, lowering sea level by ∼60 m. However, direct or indirect evidence of where changes in the ice sheet occurred is limited. Here we present new insights on timing and locations of ice sheet change from two drill sites offshore East Antarct...

Geological records from the Antarctic margin offer direct evidence of environmental variability at high southern latitudes and provide insight regarding ice sheet sensitivity to past climate change. The early to mid-Miocene (23–14 Mya) is a compelling interval to study as global temperatures and atmospheric CO2 concentrations were similar to those...

Current and past studies suggest transport processes in the lower shoreface may be responsible for the exchange of sediment between the shoreface and inner shelf, as implied by the presence of shore attached ridges and associated bedforms. Lower shoreface transport may be a significant component of coastal sediment budgets, potentially supplying se...

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...

This chapter documents the primary operational, curatorial, and analytical procedures and methods employed during the offshore and onshore phases of Integrated Ocean Drilling Program (IODP) Expedition 347. This information concerns only shipboard and Onshore Science Party (OSP) methodologies and data as described in the site chapters. Methods for p...

Integrated Ocean Drilling Program Expedition 347 aimed to retrieve sediments from different settings of the Baltic Sea, encompassing the last interglacial–glacial cycle to address scientific questions along four main research themes: 1. Climate and sea level dynamics of marine isotope Stage (MIS) 5, including onsets and terminations; 2. Complexitie...

Introduction During Integrated Ocean Drilling Program (IODP) Expedition 347, cores were recovered from two holes at Site M0066 (Born-holm Basin), with an average site recovery of 77.7%. The water depth was 82 m, with a tidal range of <10 cm. Existing data sets, including seismic reflection profiles, were evaluated prior to coring to attempt to guid...

Introduction During Integrated Ocean Drilling Program (IODP) Expedition 347, cores were recovered from four holes at Site M0062 (Ånger-manälven River estuary), with an average site recovery of 99%. In addition, two shallow gravity (Rumohr) cores were acquired. The water depth was 69.3 m, with no tidal range. Existing data sets, including seismic re...

Distinguishing sea-ice-rafted debris (SIRD) from iceberg-rafted debris is crucial to an interpretation of ice-rafting history; however, there are few paleo-sea-ice proxies. This study characterizes quartz grain microfeatures of modern SIRD from the Arctic Ocean, and compares these results with microfeatures from representative glacial deposits to p...

The Pliocene and Early Pleistocene, between 5.3 and 0.8 million years ago, span a transition from a global climate state that was 2–3 °C warmer than present with limited ice sheets in the Northern Hemisphere to one that was characterized by continental-scale glaciations at both poles. Growth and decay of these ice sheets was paced by variations in...

During the early Pliocene a dynamic marine-based ice sheet retreated from the Wilkes Land margin with periodic ice advances beyond Last Glacial Maximum position. A change in sand provenance is indicative of a more stable Mertz Glacier system during the Late Pleistocene. East Antarctic Ice Sheet (EAIS) dynamics were evaluated through the analysis of...

The data point to a dynamic interplay of fluvial and marine systems in the southern part of the North Sea driven by longer term (>100 ka) tectonic and epeirogenic processes and shorter term (<10 ka) climatic processes 1 . The formation and preservation of the Rhine-Meuse sequence is related to long term (>100 ka) uplift of the Wealden-Artois syncli...

Warm intervals within the Pliocene epoch (5.33-2.58 million years ago) were characterized by global temperatures comparable to those predicted for the end of this century(1) and atmospheric CO2 concentrations similar to today(2-4). Estimates for global sea level highstands during these times(5) imply possible retreat of the East Antarctic ice sheet...

Mapping the Middle to Upper Pleistocene Rhine-Meuse sequence in the southern North Sea based on new core and seismic data has allowed a detailed palaeoenvironmental re-assessment. An integrated seismo-lithostratigraphic and malacological biostratigraphic framework is correlated with the optically stimulated luminescence-dated Rhine-Meuse sequence o...

The warmest global temperatures of the past 85 million years occurred during a prolonged greenhouse episode known as the Early Eocene Climatic Optimum (52-50 Ma). The Early Eocene Climatic Optimum terminated with a long-term cooling trend that culminated in continental-scale glaciation of Antarctica from 34 Ma onward. Whereas early studies attribut...

During the middle and late Eocene (∼48-34 Myr ago), the Earth's climate cooled1,2 and an ice sheet built up on Antarctica. The stepwise expansion of ice on Antarctica3,4induced crustal deformation and gravitational perturbations around the continent. Close to the ice sheet, sea level rose5,6despite an overall reduction in the mass of the ocean caus...

Southern Change Antarctica has been mostly covered by ice since the inception of large-scale continental glaciation during the Oligocene, which profoundly altered the isotopic and mineralogical records of the sediments surrounding the continent. Houben et al. (p. 341 ) found records of the corresponding living systems in the fossil marine dinoflage...

The AND-2A drillhole at ca. 10 km from the east Antarctic coastline records nearly 6 million years of sedimentation across the Miocene Climatic Optimum at a high-latitude site. Sedimentological studies of bedforms and particle size distributions indicate that the paleoenvironment was strongly affected by waves and currents, consistent with depositi...

The circum-Antarctic Southern Ocean is an important region for global marine food webs and carbon cycling because of sea-ice formation and its unique plankton ecosystem. However, the mechanisms underlying the installation of this distinct ecosystem and the geological timing of its development remain unknown. Here, we show, on the basis of fossil ma...

Few high-latitude terrestrial records document the timing and nature of the Cenozoic "Greenhouse" to "Icehouse" transition. Here we exploit the bulk geochemistry of marine siliciclastic sediments from drill cores on Antarctica's continental margin to extract a unique semiquantitative temperature and precipitation record for Eocene to mid-Miocene (~...

The warmest global climates of the past 65 million years occurred during the early Eocene epoch (about 55 to 48 million years ago), when the Equator-to-pole temperature gradients were much smaller than today and atmospheric carbon dioxide levels were in excess of one thousand parts per million by volume. Recently the early Eocene has received consi...

The Integrated Ocean Drilling Program Expedition 318 to the Wilkes Land margin of Antarctica recovered a sedimentary succession ranging in age from lower Eocene to the Holocene. Excellent stratigraphic control is key to understanding the timing of paleoceanographic events through critical climate intervals. Drill sites recovered the lower and middl...

The Miocene Climatic Optimum (17–15 Ma) and the rapid cooling of the Middle Miocene Climate Transition (15–13 Ma) together signal a major change in Earth's climate system. Here we examine the sediment prov-enance in the AND-2A drill core, located 10 km from the East Antarctic coastline, to significantly increase our understanding of Antarctic ice d...

1] Ice‐rafted debris mass accumulation rates (IRD MAR) at a drill site on the Antarctic continental margin are investigated to evaluate the linkages between East Antarctic Ice Sheet extent and Southern Ocean temperatures in the early to mid‐Pliocene. ODP Site 1165 is within 400 km of the Antarctic coastline and in the direct pathway of icebergs rel...

Sites U1356 and U1359 were drilled during IODP Expedition 318 at the Antarctic margin off Wilkes Land. Site U1356 penetrated the regional unconformity expected to reflect the arrival of the first ice sheet on the Wilkes Land continental margin, as well as a number of younger unconformities. Regional unconformities provide important constraints on h...

It has become widely appreciated that the initiation of major Antarctic glaciation occurred around Eocene - Oligocene boundary times (~34-33 Ma). Some studies suggest that this greenhouse-icehouse transition (GIT) invoked a more productive Southern Ocean and therefore circum-Antarctic marine systems as a result of e.g., increased wind-stress and up...

In 2007, the Antarctic Geological Drilling Program (ANDRILL) drilled 1138.54 m of strata ̃10 km off the East Antarctic coast, includ ing an expanded early to middle Miocene succession not previously recovered from the Antarctic continental shelf. Here, we pre sent a facies model, distribution, and paleoclimatic interpretation for the AND-2A drill h...

The East Antarctic ice sheet, the largest in the world, lies seemingly frozen in time. Discovery of a rugged landscape buried beneath the thick ice provides evidence of a more dynamic past. See Letter p.72

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 hither...

In 2007, the Antarctic Geological Drilling Program (ANDRILL) drilled 1138.54 m of strata ∼10 km off the East Antarctic coast, including an expanded early to middle Miocene succession not previously recovered from the Antarctic continental shelf. Here, we present a facies model, distribution, and paleoclimatic interpretation for the AND-2A drill hol...