Evidence for reduced export productivity following the Cretaceous/Paleogene mass extinction

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doi: 10.1002/2014PA002724
Author(s): Esmeray-Senlet, Selen; Wright, James D.; Olsson, Richard K.; Miller, Kenneth G.; Browning, James V.; Quan, Tracy M.
Author Affiliation(s): Primary:
Rutgers, the State University of New Jersey, Department of Earth and Planetary Sciences, Piscataway, NJ, United States
Oklahoma State University, United States
Volume Title: Paleoceanography
Source: Paleoceanography, 30(6), p.718-738. Publisher: American Geophysical Union, Washington, DC, United States. ISSN: 0883-8305 CODEN: POCGEP
Note: In English. NSF grants EAR-070778 and OCE-0961914. 94 refs.; illus., incl. geol. sketch map
Summary: The Cretaceous/Paleogene (K/Pg) mass extinction was associated with a collapse in the carbon isotopic (δ13C) gradient between planktonic and benthic foraminifera and a decrease in bulk carbonate δ13C values. These perturbations have been explained by several hypotheses: global collapse of primary productivity (Strangelove Ocean), greatly reduced export but not primary productivity (Living Ocean), little or no reduction in export productivity (Resilient Ocean), and geographic heterogeneity in the change of export productivity (Heterogeneous Ocean). We tested primary versus export productivity changes in the paleoshelf of New Jersey, where δ13C values and organic carbon accumulation rates can distinguish among different ocean responses. On the shelf, the K/Pg boundary is associated with a ∼2.5 ppm δ13C decrease in bulk carbonate, a ∼0.8 ppm δ13C decrease in organic carbon, a collapse of the surface to bottom δ13C gradient, and a drop in organic carbon accumulation rates. We interpret an early Danian ∼1.0 ppm planktonic foraminiferal δ13C gradient, a ∼0.75 ppm cross-shelf benthic foraminiferal δ13C gradient, and a drop in carbon accumulation rates to reflect the presence of active primary but limited export productivity, consistent with the Living Ocean hypothesis. We evaluated interbasinal deep-sea benthic foraminiferal δ13C gradients between the Pacific (Site 1210) and Atlantic (Site 1262) oceans as a proxy for changes in export productivity. The interbasinal δ13C gradient was reduced after the mass extinction, suggesting a reduction in global export productivity. Although our data support the Living Ocean hypothesis, evidence from paleoupwelling zones shows significant export productivity, indicating spatial heterogeneity in the wake of the K/Pg mass extinction (Heterogeneous Ocean). Abstract Copyright (2015), . American Geophysical Union. All Rights Reserved.
Year of Publication: 2015
Research Program: ODP Ocean Drilling Program
Key Words: 02 Geochemistry; 12 Stratigraphy, Historical Geology and Paleoecology; Ancora New Jersey; Assemblages; Atlantic Coastal Plain; Atlantic Ocean; Bass River; Biostratigraphy; Biozones; Burlington County New Jersey; C-13/C-12; Camden County New Jersey; Carbon; Carbon cycle; Cenozoic; Cretaceous; Foraminifera; Geochemical cycle; Invertebrata; Isotope ratios; Isotopes; K-T boundary; Leg 150X; Leg 174AX; Leg 198; Leg 208; Lower Paleocene; Marine environment; Mass extinctions; Mesozoic; Microfossils; New Jersey; Nitrogen; North Pacific; Northwest Pacific; ODP Site 1210; ODP Site 1262; Ocean Drilling Program; Organic compounds; Pacific Ocean; Paleocene; Paleoecology; Paleoenvironment; Paleogene; Paleotemperature; Planktonic taxa; Productivity; Protista; Shatsky Rise; Shelf environment; South Atlantic; Stable isotopes; Stratigraphic boundary; Tertiary; Total organic carbon; United States; Upper Cretaceous; Walvis Ridge; West Pacific
Coordinates: N393500 N401200 W0742200 W0750500
N321300 N321300 E1581600 E1581600
S271100 S271100 E0013500 E0013400
Record ID: 2015088746
Copyright Information: GeoRef, Copyright 2019 American Geosciences Institute. Reference includes data from John Wiley & Sons, Chichester, United Kingdom