Thomas, Ellen and Roehl, Ursula (2002): The Paleocene-Eocene thermal maximum in Ceara Rise Hole 929E, ODP Leg 154

Leg/Site/Hole:
ODP 113
ODP 154
DSDP 74
DSDP 74 525
DSDP 74 527
ODP 113 689
ODP 113 690
ODP 154 929
Identifier:
2005-009092
georefid

Creator:
Thomas, Ellen
Wesleyan University, Department of Earth and Environmental Sciences, Middletown, CT, United States
author

Roehl, Ursula
Universitaet Bremen, Federal Republic of Germany
author

Identification:
The Paleocene-Eocene thermal maximum in Ceara Rise Hole 929E, ODP Leg 154
2002
In: Anonymous, Geological Society of America, 2002 annual meeting
Geological Society of America (GSA), Boulder, CO, United States
34
6
462
The main goal of Ocean Drilling Program Leg 154 (Ceara Rise, western equatorial Atlantic; 5 degrees 58'N, 43 degrees 44'W, water depth 4356 m) was to study Neogene deep-water chemistry, but Hole 929E was drilled down into Paleocene-Eocene calcareous claystone to clayey nannofossil limestone. The PETM, however, was not identified. We used relatively fast core-logging methods to obtain continuous non-destructive chemical data (X-ray fluorescence [XRF] Core Scanner) at much finer spatial scales than is practical for individual sampling methods, identified the occurrence of the PETM, and studied its sedimentological, benthic foraminiferal and environmental changes. We obtained a high-resolution record of elemental concentrations in the deepest cores from Hole 929E (751 to 809 mbsf). Our XRF data documented a sharp Fe increase and Ca decrease (typical for the rapid environmental change at the PETM at other sites) in a prominent, 40 cm-thick, brown, calcareous claystone. Isotope analysis of bulk sediments at a sample resolution of 2 cm across this horizon showed the characteristic negative carbon isotope excursion (CIE). Benthic foraminifera were badly preserved, with many specimens crushed, but the benthic foraminiferal extinction occurred at the CIE: diverse faunas with common specimens of Stensioeina beccariiformis and other typical Paleocene species were replaced rapidly by low diversity faunas dominated by Nuttalides truempyi, abyssaminids, and agglutinated species such as Glomospira spp. In the interval of peak Fe-values, many specimens of N. truempyi are filled with pyrite. These faunas are thus dominated by species that may be opportunistic, but indicate a low food supply. Post-extinction faunas at Walvis Ridge Sites 525 and 527 are also dominated by such "low food supply faunas", whereas faunas at Weddell Sea Sites 689 and 690, and equatorial Pacific Site 865 indicate a high food supply. The Ca-values suggest that CaCO (sub 3) % did not drop as low as at the Walvis Ridge sites, but the post-extinction foraminiferal faunas at Site 929 contain a much higher percentage of agglutinants than the Walvis Ridge faunas. Our data demonstrate that we can locate PETM sediments at sites where they were not identified, so that we can document the spatial and bathyal variability of this event, which is important for its understanding.
English
Coverage:Geographic coordinates:
North:5.5834
West:-43.4423East: -43.4423
South:5.5834

Stratigraphy; Atlantic Ocean; benthic taxa; calcium carbonate; carbonate rocks; Ceara Rise; Cenozoic; chemostratigraphy; clastic rocks; claystone; Deep Sea Drilling Project; DSDP Site 525; DSDP Site 527; Eocene; extinction; Foraminifera; Glomospira; high-resolution methods; horizons; Invertebrata; IPOD; Leg 113; Leg 154; Leg 74; limestone; lower Eocene; microfossils; North Atlantic; Nuttalides truempyi; Ocean Drilling Program; ODP Site 689; ODP Site 690; ODP Site 929; Paleocene; Paleogene; Protista; sampling; sedimentary rocks; South Atlantic; Southern Ocean; spectra; Stensioeina beccariiformis; stratigraphic boundary; Tertiary; upper Paleocene; variations; Walvis Ridge; Weddell Sea; X-ray fluorescence spectra;

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