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| Titel |
Early Eocene hyperthermals record orbitally controlled changes in high latitude climates |
| VerfasserIn |
S. Galeotti, R. M. DeConto, L. Lanci, M. Pagani, U. Röhl, T. Westerhold, J. C. Zachos |
| Konferenz |
EGU General Assembly 2012
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 14 (2012) |
| Datensatznummer |
250070261
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| Zusammenfassung |
| The Late Paleocene to Early Eocene records a succession of short-term (104 yr) negative
carbon isotope excursions (CIEs) in marine carbonates and organic carbon. Available data
indicate that at least three of these episodes, including the Paleocene Eocene Thermal
Maximum (PETM) at ca. 55.5, the Eocene Thermal Maximum (ETM)2 at ca. 53.5 Ma and
the ETM3 at ca. 52 Ma, were associated with rapid warming, and widespread marine
carbonate dissolution forced by shoaling of the carbonate lysocline and lowering of the
carbonate saturation state. Large temperature raises associated with decreased δ13C values in
both terrestrial and oceanic records and concomitant acidification of oceanic waters
implies that hyperthermals were caused by the addition of massive amounts of
13C-depleted greenhouse gases (CH4 and/or CO-2) into the atmosphere and subsequent
sequestration by oceanic waters. Cyclostratigraphic analyses of marine sequences provided
evidence that CIEs and associated carbonate dissolution episodes were linked to orbital
changes in insolation. Here we show grounds that Early Eocene hyperthermals are
part of a continuum of δ13C anomaly and carbonate dissolution episodes and are
triggered by long-term orbitally-controlled changes in local climates at high latitudes. |
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