Dynamics of sediment flux to a bathyal continental margin section through the Paleocene–Eocene Thermal Maximum
<p>The response of the Earth system to greenhouse-gas-driven warming is of critical importance for the future trajectory of our planetary environment. Hyperthermal events – past climate transients with global-scale warming significantly above background climate variability – can provide ins...
| Main Authors: | , , , , , , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2018-07-01
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| Series: | Climate of the Past |
| Online Access: | https://www.clim-past.net/14/1035/2018/cp-14-1035-2018.pdf |
| Summary: | <p>The response of the Earth system to greenhouse-gas-driven warming is of
critical importance for the future trajectory of our planetary environment.
Hyperthermal events – past climate transients with global-scale warming
significantly above background climate variability – can provide insights
into the nature and magnitude of these responses. The largest hyperthermal of
the Cenozoic was the Paleocene–Eocene Thermal Maximum (PETM  ∼  56 Ma).
Here we present new high-resolution bulk sediment stable isotope and major
element data for the classic PETM section at Zumaia, Spain. With these data we
provide a new detailed stratigraphic correlation to other key deep-ocean and
terrestrial PETM reference sections. With this new correlation and age model
we are able to demonstrate that detrital sediment accumulation rates within
the Zumaia continental margin section increased more than 4-fold during
the PETM, representing a radical change in regional hydrology that drove
dramatic increases in terrestrial-to-marine sediment flux. Most remarkable is
that detrital accumulation rates remain high throughout the body of the PETM,
and even reach peak values during the recovery phase of the characteristic
PETM carbon isotope excursion (CIE). Using a series of Earth system model
inversions, driven by the new Zumaia carbon isotope record, we demonstrate
that the silicate weathering feedback alone is insufficient to recover the
PETM CIE, and that active organic carbon burial is required to match the
observed dynamics of the CIE. Further, we demonstrate that the period of maximum organic
carbon sequestration coincides with the peak in detrital accumulation rates
observed at Zumaia. Based on these results, we hypothesise that orbital-scale
variations in subtropical hydro-climates, and their subsequent impact on
sediment dynamics, may contribute to the rapid climate and CIE recovery from
peak-PETM conditions.</p> |
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| ISSN: | 1814-9324 1814-9332 |