Creative disturbance: sedimentary perturbations as paleoenvironmental proxies
Abstract
"Ideal" paleoclimate archives are often characterized as those with continuous and relatively monotonous sedimentation. For the paleoceanographic community attention has typically focused on deep-ocean pelagic sedimentary sequences that are largely unperturbed by terrestrial surface processes. The quality of microfossil and organic biomarker preservation within clay-rich continental margin successions, has, however, refocused attention on generating geochemical and micropaleontological proxy records from shelf and slope environments. The sedimentology of these continental margin environments can, however, itself be sensitive to components of the climate system that are under study. Here, we present two case studies from continental margin successions - from northwest Spain and the US Gulf Coast - where the paleoclimate archive is substantially "disturbed" by major changes in terrestrial surface processes. These are associated with two large climate perturbations - global warming at the Paleocene Eocene Thermal Maximum (PETM) and sea level fall at the Eocene / Oligocene Transition - that generate marked changes in sediment flux between continental interiors and the marine continental margin. In these cases we argue that these sedimentary responses are not only useful for recreating major changes in local to regional paleoenvironments, but that changes in weathering, erosion, sediment and carbon flux may be a key component in modulating the carbon cycle through these intervals.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2018
- Bibcode:
- 2018AGUFMEP42A..04D
- Keywords:
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- 1041 Stable isotope geochemistry;
- GEOCHEMISTRYDE: 1051 Sedimentary geochemistry;
- GEOCHEMISTRYDE: 1616 Climate variability;
- GLOBAL CHANGEDE: 1641 Sea level change;
- GLOBAL CHANGEDE: 1824 Geomorphology: general;
- HYDROLOGYDE: 1849 Numerical approximations and analysis;
- HYDROLOGYDE: 1861 Sedimentation;
- HYDROLOGYDE: 1862 Sediment transport;
- HYDROLOGY