Continental ice in Greenland during the Eocene and Oligocene

  title={Continental ice in Greenland during the Eocene and Oligocene},
  author={James S. Eldrett and Ian C. Harding and Paul A. Wilson and Emily Butler and Andrew P. Roberts},
The Eocene and Oligocene epochs (∼55 to 23 million years ago) comprise a critical phase in Earth history. An array of geological records supported by climate modelling indicates a profound shift in global climate during this interval, from a state that was largely free of polar ice caps to one in which ice sheets on Antarctica approached their modern size. However, the early glaciation history of the Northern Hemisphere is a subject of controversy. Here we report stratigraphically extensive ice… 

Evidence for ephemeral middle Eocene to early Oligocene Greenland glacial ice and pan-Arctic sea ice

Evidence is found for episodic glaciation of distinct source regions on Greenland as far-ranging as ~68°N and ~80°N synchronous with ice-rafting from circum-Arctic sources, beginning in the middle Eocene, which represents the Cenozoic onset of a dynamic cryosphere.

No extreme bipolar glaciation during the main Eocene calcite compensation shift

Test the hypothesis that large ice sheets were present in both hemispheres ∼41.6 million years ago using marine sediment records of oxygen and carbon isotope values and of calcium carbonate content from the equatorial Atlantic Ocean to resolve the apparent discrepancy between the geological records of Northern Hemisphere glaciation.

North Atlantic Evidence for a Unipolar Icehouse Climate State at the Eocene‐Oligocene Transition

Earth's climate transitioned from a warm unglaciated state to a colder glaciated “icehouse” state during the Cenozoic. Extensive ice sheets were first sustained on Antarctica at the Eocene‐Oligocene

Thresholds for Cenozoic bipolar glaciation

It is found that Oi-1 is best explained by Antarctic glaciation alone, combined with deep-sea cooling of up to 4 °C and Antarctic ice that is less isotopically depleted than previously suggested, which implies that episodic northern-hemispheric ice sheets have been possible some 20 million years earlier than currently assumed and could explain some of the variability in Miocene sea-level records.

Sedimentological and oceanographic change in the Northwest Atlantic Ocean across the Eocene Oligocene Transition

The Eocene-Oligocene Transition (EOT) marks the most pivotal interval in Earth’s Cenozoic transition from warm, relatively ice-free ‘greenhouse’ conditions to a cooler ‘icehouse’ climate. The EOT saw

The State of the Oligocene Icehouse World: Sedimentology, Provenance, and Stable Isotopes of Marine Sediments from the Antarctic Continental Margin

Ice-rafted debris concentrations and Ar/Ar thermochronology from Integrated Ocean Drilling Program (IODP) Site U1356 reveal an ice sheet was consistently present in the Wilkes subglacial basin (WSB)

Onset of long-term cooling of Greenland near the Eocene-Oligocene boundary as revealed by branched tetraether lipids

The Eocene-Oligocene (E-O) boundary interval is considered to be one of the major transitions in Earth’s climate, witnessing the fi rst major expansion of the East Antarctic Ice Sheet. However, the

Increased seasonality through the Eocene to Oligocene transition in northern high latitudes

Northern high-latitude terrestrial climate estimates for the Eocene to Oligocene interval, based on bioclimatic analysis of terrestrially derived spore and pollen assemblages preserved in marine sediments from the Norwegian–Greenland Sea indicate a cooling of ∼5 °C in cold-month (winter) mean temperatures to 0–2‬C, and a concomitant increased seasonality before the Oi-1 glaciation event.

Evidence for middle Eocene Arctic sea ice from diatoms and ice-rafted debris

The data establish a 2-Myr record of sea ice, documenting the transition from a warm, ice-free environment to one dominated by winter sea ice at the start of the middle Eocene climatic cooling phase.

Global Cooling During the Eocene-Oligocene Climate Transition

About 34 million years ago, Earth's climate shifted from a relatively ice-free world to one with glacial conditions on Antarctica characterized by substantial ice sheets. How Earth's temperature



The Cenozoic palaeoenvironment of the Arctic Ocean

This record of the Neogene reveals cooling of the Arctic that was synchronous with the expansion of Greenland ice and East Antarctic ice and supporting arguments for bipolar symmetry in climate change.

Evidence for massive discharges of icebergs into the North Atlantic ocean during the last glacial period

SEDIMENTS in the North Atlantic ocean contain a series of layers that are rich in ice-rafted debris and unusually poor in foraminifera1. Here we present evidence that the most recent six of these

Unlocking the Ice House: Oligocene‐Miocene oxygen isotopes, eustasy, and margin erosion

Oxygen isotope records and glaciomarine sediments indicate at least an intermittent presence of large continental ice sheets on Antarctica since the earliest Oligocene (circa 35 Ma). The growth and

Rapid Cenozoic glaciation of Antarctica induced by declining atmospheric CO2

In this simulation, declining Cenozoic CO2 first leads to the formation of small, highly dynamic ice caps on high Antarctic plateaux, and at a later time, a CO2 threshold is crossed, initiating ice-sheet height/mass-balance feedbacks that cause the ice caps to expand rapidly with large orbital variations, eventually coalescing into a continental-scale East Antarctic Ice Sheet.

Eocene bipolar glaciation associated with global carbon cycle changes

The transition from the extreme global warmth of the early Eocene ‘greenhouse’ climate ∼55 million years ago to the present glaciated state is one of the most prominent changes in Earth's climatic

Rapid stepwise onset of Antarctic glaciation and deeper calcite compensation in the Pacific Ocean

The changes in oxygen-isotope composition across the Eocene/Oligocene boundary are too large to be explained by Antarctic ice-sheet growth alone and must therefore also indicate contemporaneous global cooling and/or Northern Hemisphere glaciation.

Cenozoic deep-Sea temperatures and global ice volumes from Mg/Ca in benthic foraminiferal calcite

A deep-sea temperature record for the past 50 million years has been produced from the magnesium/calcium ratio (Mg/Ca) in benthic foraminiferal calcite. The record is strikingly similar in form to

Late Cretaceous-early Tertiary stratigraphy of the Kangerdlugssuaq area, east Greenland, and the age of opening of the north-east Atlantic

In central east Greenland, on the Blosseville Coast to the east of Kangerdiugssuaq, late Cretaceous–early Tertiary sediments (here termed the Kangerdlugssuaq Group) underlie c. 9 km of Tertiary

Central Arctic Ocean Sediment Texture: A Key to Ice Transport Mechanisms

The perennial Arctic Ocean ice-cover consists of sea ice and glacial ice. Sea ice is most common today but at times during the Late Cenozoic, glacial ice has been extremely abundant. Both sea ice and