Central Pacific ODP865 d18O and Mg/Ca Analyses from the Paleocene-Eocene Thermal Maximum Kozdon, R.; Kelly, D.C.; Kitajima, K.; Strickland, A.; Fournelle, J.H.; Valley, J.W. Kozdon, R. Kelly, D.C. Kitajima, K. Strickland, A. Fournelle, J.H. Valley, J.W. earth science/paleoclimate/paleoceanography (notes,null,null,null,null,paleoceanography,null,null,N,primary 133Cs+ beam diameter; used for delta 18O analysis) earth science/paleoclimate/paleoceanography (strontium,carbonate|planktic foraminifer,null,parts per million,null,paleoceanography,null,secondary ion mass spectrometry,N,12 um beam-spot size) earth science/paleoclimate/paleoceanography (notes,null,null,null,null,paleoceanography,null,null,C,null) earth science/paleoclimate/paleoceanography (depth,null,null,meter,null,paleoceanography,null,null,N,null) earth science/paleoclimate/paleoceanography (inorganic compound index,carbonate|planktic foraminifer,null,percent,null,paleoceanography,null,null,N,total oxides) earth science/paleoclimate/paleoceanography (sample identification,null,null,null,null,paleoceanography,null,null,C,null) earth science/paleoclimate/paleoceanography (notes,null,null,null,null,paleoceanography,null,null,N,analysis number used during this session) earth science/paleoclimate/paleoceanography (calcium dioxide,carbonate|planktic foraminifer,null,dimensionless,null,paleoceanography,null,electron probe x-ray microanalysis,N,EPMA concentration) earth science/paleoclimate/paleoceanography (magnesium,carbonate|planktic foraminifer,one standard error,percent,null,paleoceanography,null,secondary ion mass spectrometry,N,11 um beam-spot size) earth science/paleoclimate/paleoceanography (strontium,carbonate|planktic foraminifer,one standard error,percent,null,paleoceanography,null,secondary ion mass spectrometry,N,13 um beam-spot size) earth science/paleoclimate/paleoceanography (magnesium oxide,carbonate|planktic foraminifer,null,dimensionless,null,paleoceanography,null,electron probe x-ray microanalysis,N,EPMA concentration) earth science/paleoclimate/paleoceanography (age,null,null,million years ago,null,paleoceanography,null,null,N,null) earth science/paleoclimate/paleoceanography (delta 18O,carbonate|planktic foraminifer,null,per mil PDB,null,paleoceanography,null,null,N,diagenetic carbonate) earth science/paleoclimate/paleoceanography (calcium oxide,carbonate|planktic foraminifer,null,dimensionless,null,paleoceanography,null,electron probe x-ray microanalysis,N,EPMA concentration) earth science/paleoclimate/paleoceanography (magnesium,carbonate|planktic foraminifer,null,parts per million,null,paleoceanography,null,secondary ion mass spectrometry,N,10 um beam-spot size) earth science/paleoclimate/paleoceanography (strontium oxide,carbonate|planktic foraminifer,null,dimensionless,null,paleoceanography,null,electron probe x-ray microanalysis,N,EPMA concentration) earth science/paleoclimate/paleocean earth science/paleoclimate/paleocean (ODP 865>LATITUDE 18.440167>LONGITUDE -179.555667) We report d18O and minor element (Mg/Ca, Sr/Ca) data acquired by high-resolution,in situ secondary ion mass spectrometry (SIMS) from planktic foraminiferal shells and 100–500 µm sized diagenetic crystallites recovered from a deep-sea record (ODP Site 865) of the Paleocene-Eocene thermal maximum (PETM). The d18O of crystallites (~1.2‰ Pee Dee Belemnite (PDB)) is ~4.8‰ higher than that of planktic foraminiferal calcite ( 3.6‰ PDB), while crystallite Mg/Ca and Sr/Ca ratios are slightly higher and substantially lower than in planktic foraminiferal calcite, respectively. The focused stratigraphic distribution of the crystallites signals an association with PETM conditions; hence, we attribute their formation to early diagenesis initially sourced by seafloor dissolution (burndown) ensued by reprecipitation at higher carbonate saturation. The Mg/Ca ratios of the crystallites are an order of magnitude lower than those predicted by inorganic precipitation experiments, whichmay reflect a degree of inheritance from“donor” phases of biogenic calcite that underwent solution in the sediment column. In addition, SIMS d18O and electron microprobe Mg/Ca analyses that were taken within a planktic foraminiferal shell yield parallel increases along traverses that coincide with muricae blades on the chamber wall. The parallel d18O and Mg/Ca increases indicate a diagenetic origin for the blades, but their d18O value ( 0.5‰ PDB) is lower than that of crystallites suggesting that these two phases of diagenetic carbonate formed at different times. Finally, we posit that elevated levels of early diagenesis acted in concert with sediment mixing and carbonate dissolution to attenuate the d18O decrease signaling PETM warming in “wholeshell” records published for Site 865. STUDY NOTES: In situ oxygen isotope data were acquired between January and March 2011 in the WiscSIMS Laboratory at UW-Madison by a CAMECA ims-1280 large radius ion microprobe. A 133Cs+ primary ion beam with an intensity of ~1.6 nA was focused to a diameter of ~10 µm. For smaller domains, a 133Cs+ primary ion beam with an intensity of ~30 pA was focused to a diameter of ~3 µm. Charging of the sample surface was compensated by Au-coating and an electron flood gun. Grains of UWC-3 calcite standard (d18O = 12.49 per mill V-SMOW, Kozdon et al. 2009) were cast in the center of each epoxy mount. Four to five consecutive measurements of UWC-3 calcite standard were performed before and after every set of up to 15 sample analyses. SIMS analyses for minor and major element concentrations were performed using a primary O- ion beam, with an intensity of 1 nA, focused to a ~ 1.5 µm beam spot size. Further, Mg/Ca measurements in small domains were performed on the CAMECA SX51 electron microprobe at the UW-Madison Department of Geoscience. NCDC-Paleoclimatology https://www.ncdc.noaa.gov/data-access/paleoclimatology-data - Bauer Bruce Investigator : Kozdon, R. Investigator : Kelly, D.C. Investigator : Kitajima, K. Investigator : Strickland, A. Investigator : Fournelle, J.H. Investigator : Valley, J.W. 2014-11-04 ONLINE Files online, ASCII https://www.ncdc.noaa.gov/paleo/study/17397 https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/kozdon2013/kozdon2013-epma.txt https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/kozdon2013/kozdon2013-mgsr.txt https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/kozdon2013/kozdon2013-d18o.txt https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/kozdon2013/kozdon2013-epma.txt https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/kozdon2013/kozdon2013-mgsr.txt https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/kozdon2013/kozdon2013-d18o.txt English https://www.ncdc.noaa.gov/paleo/study/17397 https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/kozdon2013/kozdon2013-epma.txt https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/kozdon2013/kozdon2013-mgsr.txt https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/kozdon2013/kozdon2013-d18o.txt Kozdon, R., D.C. Kelly, K. Kitajima, A. Strickland, J.H. Fournelle, and J.W. Valley2013In situ d18O and Mg/Ca Analyses of Diagenetic and Planktic Foraminiferal Calcite Preserved in a Deep-Sea Record of the Paleocene-Eocene Thermal MaximumPaleoceanography28517-52810.1002/palo.20048 START YEAR: 55200000 cal yr BP * END YEAR: 48800000 cal yr BP -179.555667 18.440167 -179.555667 18.440167