Large temperature drop across the Eocene–Oligocene transition in central North America

  title={Large temperature drop across the Eocene–Oligocene transition in central North America},
  author={Alessandro Zanazzi and Matthew J. Kohn and Bruce J. MacFadden and Dennis O. Terry},
The Eocene–Oligocene transition towards a cool climate (∼33.5 million years ago) was one of the most pronounced climate events during the Cenozoic era. The marine record of this transition has been extensively studied. However, significantly less research has focused on continental climate change at the time, yielding partly inconsistent results on the magnitude and timing of the changes. Here we use a combination of in vivo stable isotope compositions of fossil tooth enamel with diagenetic… 

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.

Terrestrial cooling in Northern Europe during the Eocene–Oligocene transition

The authors' data show a decrease in growing-season surface water temperatures corresponding to an average decrease in mean annual air temperature from the Late Eocene to Early Oligocene, which suggests a close linkage between atmospheric carbon dioxide concentrations, Northern Hemisphere temperature, and expansion of the Antarctic ice sheets.

Orogeny forced terrestrial climate variation during the late Eocene–early Oligocene in Europe

Terrestrial climatic data reflect variable and often conflicting responses to the global cooling event at the Eocene-Oligocene transition (ca. 34 Ma). Stable isotopic compositions of the tooth enamel

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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

Eocene to Oligocene terrestrial Southern Hemisphere cooling caused by declining pCO2

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Continental Climatic and Weathering Response to the Eocene-Oligocene Transition

Paleoclimatic reconstructions of the Eocene-Oligocene transition indicate significant spatial heterogeneity in both the marine and the terrestrial responses to the formation of ice sheets on

Orbital climate variability on the northeastern Tibetan Plateau across the Eocene–Oligocene transition

It is concluded that this terrestrial orbital response transition coincided with a similar transition in the marine benthic δ18O record for global ice volume and deep-sea temperature variations and was a response to coeval atmospheric CO2 decline and continental-scale Antarctic glaciation.

Heterogeneity in global vegetation and terrestrial climate change during the late Eocene to early Oligocene transition

The first global vegetation and terrestrial temperature reconstructions for the EOT are presented and it is concluded that the heterogeneous pattern of global vegetation change has been controlled by a combination of multiple forcings, such as tectonics, sea-level fall and long-term decline in greenhouse gas concentrations during the late Eocene to early Oligocene.



Cooler winters as a possible cause of mass extinctions at the Eocene/Oligocene boundary

Stable oxygen isotope measurements of aragonite in fish otoliths—ear stones—collected across the Eocene/Oligocene boundary are reported, suggesting that temperature variability, rather than change in mean annual temperature, helped to cause faunal turnover during this transition.

Eocene-Oligocene Climatic and Biotic Evolution

The transition from the Eocene to the Oligocene epoch was the most significant event in Earth history since the extinction of dinosaurs. As the first Antarctic ice sheets appeared, major extinctions

Evolution of Early Cenozoic marine temperatures

The equator to high southern latitude sea surface and vertical temperature gradients are reconstructed from oxygen isotope values of planktonic and benthic foraminifers for the following five time

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.

Tertiary oxygen isotope synthesis, sea level history, and continental margin erosion

Tertiary benthic and planktonic foraminiferal oxygen isotope records are correlated to a standard geomagnetic polarity time scale, making use of improved chronostratigraphic control and additional

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.

Single-Crystal 40Ar/39Ar Dating of the Eocene-Oligocene Transition in North America

The Eocene-Oligocene boundary, and its associated climate change and extinction events, as a result, correlates with the Chadronian-Orellan boundary, not the Duchesnean-Chadronian boundary.

Tectonic Controls on Isotope Compositions and Species Diversification, John Day Basin, Central Oregon

18 O from ~ 27 Ma to ~ 7 Ma, followed by a dramatic ~ 4‰ decrease to the present. The isotope composition of fossil teeth is strongly affected by rainout over the Cascades, so these trends likely