Planktic foraminiferal response to the "latest Danian event" (62.15 Ma) on an almost global scale; results from Shatsky Rise, Walvis Ridge and Newfoundland

Author(s): Jehle, Sofie; Bornemann, Andre; Deprez, Andre; Speijer, Robert P.
Author Affiliation(s): Primary:
University of Leipzig, Leipzig, Germany
Other:
Bundesanstalt für Geowissenschaften und Rohstoffe, Germany
Katholieke Universiteit Leuven, Belgium
Volume Title: AGU 2015 fall meeting
Source: American Geophysical Union Fall Meeting, Vol.2015; American Geophysical Union 2015 fall meeting, San Francisco, CA, Dec. 14-18, 2015. Publisher: American Geophysical Union, Washington, DC, United States
Note: In English
Summary: The marine ecosystem of the Paleocene was disturbed by several transient warming events. One of these is the Latest Danian Event (LDE aka "Top C27n Event"). In deep-sea records the LDE is usually characterized by two distinctive XRF Fe peaks, paralleled by a ∼0.7 ppm negative δ13C excursion (prev. publ.). Here we present new stable isotope and faunal datasets from planktic foraminifera representing three ocean basins: The Pacific is covered by ODP Site 1210, the South Atlantic by ODP Site 1262 and the North Atlantic by IODP Site U1407. We compare the generated datasets in aspects of biotic response (planktic foraminifera), carbonate preservation as well as δ18O and δ13C signals of surface, subsurface and benthic taxa covering a time span of 900 kyr around the event to figure out to what extent the LDE influenced oceans and biota. At Site 1210 a drop in planktic and benthic δ18O record suggest a temperature rise of ∼2.5°C within 100 ky which is on the same scale as the benthic δ18O shift at 1209 (prev. publ.) suggesting the LDE to be a further potential Paleocene hyperthermal. Multivariate statistics imply distinct faunal changes starting below the LDE. A different assemblage after the event was observed specifically in photosymbiont-bearing taxa including the disappearance of Praemurica spp. and the strong increase of Igorina albeari. Minor dissolution is considered to be present during the LDE according to enhanced test fragmentation and decreased CaCO3 and planktic foraminifera test abundance. A rising δ13C gradient between surface and subsurface dwelling foraminifera suggests sudden increased stratification of the upper water column ∼100 ky below the LDE, strongly enhanced during it and less but still high above it. This might include a shallower thermocline and be linked to the development of a deep-chlorophyll maximum. Faunal assemblages of 1262 show a similar development with an overall higher abundance of subsurface dwellers. Multivariate statistisc hint towards a change of the community during and after the LDE in contrast to Site 1210. Benthic δ18O and δ13C reflect the two Fe peaks and imply a ∼2.8°C bottom water warming. Bulk-rock δ13C trends of U1407 are comparable to the other sites, the CaCO3 record shows strong response to the event, but a distinct lithological expression of the LDE is not apparent.
Year of Publication: 2015
Research Program: ODP Ocean Drilling Program
Key Words: 12 Stratigraphy, Historical Geology and Paleoecology; Cenozoic; Danian; Foraminifera; Invertebrata; Leg 198; Lower Paleocene; Microfossils; North Pacific; Northwest Pacific; ODP Site 1210; Ocean Drilling Program; Pacific Ocean; Paleo-oceanography; Paleocene; Paleoecology; Paleogene; Protista; Shatsky Rise; Tertiary; West Pacific
Coordinates: N321300 N321300 E1581600 E1581600
Record ID: 2016109762
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