Spatiotemporal patterns of carbonate sedimentation in the South Atlantic; implications for carbon cycling during the Paleocene-Eocene Thermal Maximum

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doi: 10.1016/j.palaeo.2010.04.027
Author(s): Kelly, Daniel C.; Nielsen, Tina M. J.; McCarren, Heather K.; Zachos, James C.; Röhl, Ursula
Author Affiliation(s): Primary:
University of Wisconsin, Department of Geoscience, Madison, WI, United States
University of California, Santa Cruz, United States
University of Bremen, Federal Republic of Germany
Volume Title: Palaeogeography, Palaeoclimatology, Palaeoecology
Source: Palaeogeography, Palaeoclimatology, Palaeoecology, 293(1-2), p.30-40. Publisher: Elsevier, Amsterdam, Netherlands. ISSN: 0031-0182 CODEN: PPPYAB
Note: In English. Supplemental information/data is available in the online version of this article. 73 refs.; illus., incl. sects., sketch map
Summary: Rapid carbon input into the ocean-atmosphere system caused a dramatic shoaling of the lysocline during the Paleocene-Eocene thermal maximum (PETM), a transient (∼170kyr) global warming event that occurred roughly 55Ma. Carbon cycle models invoking an accelerated carbonate-silicate feedback mechanism to neutralize ocean acidification predict that the lysocline would subsequently deepen to depths below its original position as the marine carbonate system recovered from such a perturbation. To test this hypothesis, records of carbonate sedimentation and preservation for PETM sections in the Weddell Sea (ODP Site 690) and along the Walvis Ridge depth transect (ODP Sites 1262, 1263, and 1266) were assembled within the context of a unified chronostratigraphy. The meridional gradient of undersaturation delimited by these records shows that dissolution was more severe in the subtropical South Atlantic than in the Weddell Sea during the PETM, a spatiotemporal pattern inconsistent with the view that Atlantic overturning circulation underwent a transient reversal. Deepening of the lysocline following its initial ascent is signaled by increases in %CaCO3 and coarse-fraction content at all sites. Carbonate preservation during the recovery period is appreciably better than that seen prior to carbon input with carbonate sedimentation becoming remarkably uniform over a broad spectrum of geographic and bathymetric settings. These congruent patterns of carbonate sedimentation confirm that the lysocline was suppressed below the depth it occupied prior to carbon input, and are consistent with the view that an accelerated carbonate-silicate geochemical cycle played an important role in arresting PETM conditions. Abstract Copyright (2010) Elsevier, B.V.
Year of Publication: 2010
Research Program: ODP Ocean Drilling Program
Key Words: 12 Stratigraphy, Historical Geology and Paleoecology; Atlantic Ocean; Bioclastic sedimentation; Carbon; Carbon cycle; Carbonate sediments; Cenozoic; Climate change; Foraminifera; Geochemical cycle; Global change; Global warming; Invertebrata; Leg 208; Marine sedimentation; Marine sediments; Microfossils; ODP Site 1262; ODP Site 1263; ODP Site 1266; Ocean Drilling Program; Paleocene-Eocene Thermal Maximum; Paleoclimatology; Paleogene; Planktonic taxa; Preservation; Protista; Sedimentation; Sediments; South Atlantic; Spatial distribution; Temporal distribution; Tertiary; Walvis Ridge
Coordinates: S271100 S271100 E0013500 E0013400
S283200 S283200 E0024700 E0024700
S283300 S283200 E0022100 E0022000
Record ID: 2010070249
Copyright Information: GeoRef, Copyright 2019 American Geosciences Institute. Reference includes data from CAPCAS, Elsevier Scientific Publishers, Amsterdam, Netherlands