Carbonate saturation dynamics during the Paleocene-Eocene Thermal Maximum; bathyal constraints from ODP Sites 689 and 690 in the Weddell Sea (South Atlantic)

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doi: 10.1016/j.margeo.2012.02.003
Author(s): Kelly, D. Clay; Nielsen, Tina M. J.; Schellenberg, Stephen A.
Author Affiliation(s): Primary:
University of Wisconsin, Department of Geoscience, Madison, WI, United States
Other:
San Diego State University, United States
Volume Title: Marine Geology
Source: Marine Geology, Vol.303-306, p.75-86. Publisher: Elsevier, Amsterdam, Netherlands. ISSN: 0025-3227 CODEN: MAGEA6
Note: In English. 75 refs.; illus., incl. 1 table, sketch map
Summary: Spatiotemporal patterns of carbonate dissolution provide a critical constraint on carbon input during an ancient (∼55.5Ma) global warming event known as the Paleocene-Eocene thermal maximum (PETM), yet the magnitude of lysocline shoaling in the Southern Ocean is poorly constrained due to limited spatial coverage in the circum-Antarctic region. This shortcoming is partially addressed by comparing patterns of carbonate sedimentation at the Site 690 PETM reference section to those herein reconstructed for nearby Site 689. Biochemostratigraphic correlation of the two records reveals that the first ∼36ka of the carbon isotope excursion (CIE) signaling PETM conditions is captured by the Site 689 section, while the remainder of the CIE interval and nearly all of the CIE recovery are missing due to a coring gap. A relatively expanded stratigraphy and higher carbonate content at mid-bathyal Site 689 indicate that dissolution was less severe than at Site 690. Thus, the bathymetric transect delimited by these two PETM records indicates that the lysocline shoaled above Site 689 (∼1,100m) while the calcite compensation depth remained below Site 690 (∼1,900m) in the Weddell Sea region. The ensuing recovery of carbonate sedimentation conforms to a bathymetric trend best explained by gradual lysocline deepening as negative feedback mechanisms neutralized ocean acidification. Further, biochemostratigraphic evidence indicates the tail end of the CIE recovery interval at both sites has been truncated by a hiatus most likely related to vigorous production and advection of intermediate waters. Abstract Copyright (2012) Elsevier, B.V.
Year of Publication: 2012
Research Program: ODP Ocean Drilling Program
Key Words: 12 Stratigraphy, Historical Geology and Paleoecology; Biostratigraphy; C-13/C-12; Calcium carbonate; Carbon; Carbonates; Cenozoic; Chemostratigraphy; Chronostratigraphy; Cores; Correlation; Foraminifera; Invertebrata; Isotope ratios; Isotopes; Leg 113; Lithofacies; Marine environment; Maud Rise; Microfossils; ODP Site 689; ODP Site 690; Ocean Drilling Program; Paleo-oceanography; Paleocene-Eocene Thermal Maximum; Paleogene; Preservation; Protista; Saturation; Sedimentation; Sedimentation rates; Southern Ocean; Stable isotopes; Tertiary; Weddell Sea
Coordinates: S643101 S643100 E0030600 E0030559
S650938 S650937 E0011218 E0011218
Record ID: 2012063191
Copyright Information: GeoRef, Copyright 2017 American Geosciences Institute. Reference includes data from CAPCAS, Elsevier Scientific Publishers, Amsterdam, Netherlands