Diverse patterns of ocean export productivity change across the Cretaceous-Paleogene boundary; new insights from biogenic barium

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doi: 10.1029/2010PA002082
Author(s): Hull, Pincelli M.; Norris, Richard D.
Author Affiliation(s): Primary:
Scripps Institution of Oceanography, La Jolla, CA, United States
Volume Title: Paleoceanography
Source: Paleoceanography, 26(3). Publisher: American Geophysical Union, Washington, DC, United States. ISSN: 0883-8305 CODEN: POCGEP
Note: In English. 79 refs.; illus., incl. sketch map
Summary: One of the best-studied aspects of the K-Pg mass extinction is the decline and subsequent recovery of open ocean export productivity (e.g., the flux of organic matter from the surface to deep ocean). Some export proxies, including surface-to-deep water δ13C gradients and carbonate sedimentation rates, indicate a global decline in export productivity triggered by the extinction. In contrast, benthic foraminiferal and other geochemical productivity proxies suggest spatially and temporally heterogeneous K-Pg boundary effects. Here we address these conflicting export productivity patterns using new and compiled measurements of biogenic barium. Unlike a previous synthesis, we find that the boundary effect on export productivity and the timing of recovery varied considerably between different oceanic sites. The northeast and southwest Atlantic, Southern Ocean, and Indian Ocean records saw export production plummet and remain depressed for 350 thousand to 2 million years. Biogenic barium and other proxies in the central Pacific and some upwelling or neritic Atlantic sites indicate the opposite, with proxies recording either no change or increased export production in the early Paleocene. Our results suggest that widespread declines in surface-to-deep ocean δ13C do not record a global decrease in export productivity. Rather, independent proxies, including barium and other geochemical proxies, and benthic community structure, indicate that some regions were characterized by maintained or rapidly recovered organic flux from the surface ocean to the deep seafloor, while other regions had profound reductions in export productivity that persisted long into the Paleocene.
Year of Publication: 2011
Research Program: DSDP Deep Sea Drilling Project
IPOD International Phase of Ocean Drilling
ODP Ocean Drilling Program
Key Words: 02 Geochemistry; 12 Stratigraphy, Historical Geology and Paleoecology; Alkaline earth metals; Atlantic Ocean; Ba/Ti; Barium; Biogenic processes; C-13/C-12; Carbon; Cenozoic; Cretaceous; DSDP Site 356; DSDP Site 398; DSDP Site 577; Deep Sea Drilling Project; IPOD; Indian Ocean; Isotope ratios; Isotopes; K-T boundary; Leg 113; Leg 122; Leg 198; Leg 39; Leg 47; Leg 86; Lower Paleocene; Marine environment; Mass extinctions; Maud Rise; Mesozoic; Metals; North Atlantic; North Pacific; Northwest Pacific; ODP Site 1209; ODP Site 690; ODP Site 761; Ocean Drilling Program; Organic carbon; Pacific Ocean; Paleocene; Paleoecology; Paleoenvironment; Paleogene; Preservation; Productivity; Shatsky Rise; South Atlantic; Southern Ocean; Spectra; Stable isotopes; Stratigraphic boundary; Tertiary; Titanium; Upper Cretaceous; Weddell Sea; West Pacific; Wombat Plateau; X-ray fluorescence spectra
Coordinates: N405736 N405736 W0104306 W0104306
S281713 S281713 W0410517 W0410517
S650938 S650937 E0011218 E0011218
N323900 N324000 E1583100 E1583000
Record ID: 2013092107
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