noaa-ocean-20165 Blake Ridge Chemistry, Foraminifera, Stable Isotope and Radiogenic Isotope Data for the last 35,000 Years Wycech, J.; Kelly, D.C.; Marcott, S.A. Blake Ridge Chemistry, Foraminifera, Stable Isotope and Radiogenic Isotope Data for the last 35,000 Years 2016-05-19 NCDC-Paleoclimatology ONLINE Files Pending https://www.ncdc.noaa.gov/paleo/study/20165 Investigator J. Wycech Investigator D.C. Kelly Investigator S.A. Marcott earth science paleoclimate paleoceanography notes,null,null,null,null,paleoceanography,null,null,C,Foraminiferal Shell Classification: Translucent Intermediate or Opaque earth science paleoclimate paleoceanography calcium carbonate,sediment,null,percent,null,paleoceanography,null,carbon coulometry,N,null earth science paleoclimate paleoceanography notes,null,null,null,null,paleoceanography,null,null,C,null earth science paleoclimate paleoceanography manganese/calcium,Globigerinoides ruber|Orbulina universa|Trilobatus sacculifer,two standard deviations,millimole per mole,null,paleoceanography,null,inductively-coupled plasma atomic emission spectroscopy,N,null earth science paleoclimate paleoceanography weight,Trilobatus sacculifer,null,microgram,null,paleoceanography,null,null,N,250-355 µm size fraction earth science paleoclimate paleoceanography Trilobatus sacculifer,null,null,count,null,paleoceanography,null,null,N,per foraminiferal classification; >150 µm size fraction earth science paleoclimate paleoceanography notes,null,null,null,null,paleoceanography,null,null,N,Number of sample splits >150 µm size fraction earth science paleoclimate paleoceanography Orbulina universa,null,null,count,null,paleoceanography,null,null,N,per foraminiferal classification; >150 µm size fraction earth science paleoclimate paleoceanography total planktic foraminifers,sediment,null,count,null,paleoceanography,null,null,N,>150 µm size fraction earth science paleoclimate paleoceanography notes,null,null,null,null,paleoceanography,null,null,C,Foraminifera (T. sacculifer or Polyspecific=T. sacculifer Gs. ruber O. universa) Polyspecific from >150 µm size fraction T sacculifer from 250-355 µm size fraction earth science paleoclimate paleoceanography notes,null,null,null,null,paleoceanography,null,null,C,Foraminiferal Shell Classification: Translucent or Opaque earth science paleoclimate paleoceanography delta 13C,Globigerinoides ruber|Orbulina universa|Trilobatus sacculifer|carbonate,null,per mil PDB,null,paleoceanography,null,accelerator mass spectrometry,N,Foraminifera from >150 µm size fraction earth science paleoclimate paleoceanography magnesium/calcium,Globigerinoides ruber|Orbulina universa|Trilobatus sacculifer,two standard deviations,millimole per mole,null,paleoceanography,null,inductively-coupled plasma atomic emission spectroscopy,N,null earth science paleoclimate paleoceanography manganese/calcium,Globigerinoides ruber|Orbulina universa|Trilobatus sacculifer,null,millimole per mole,null,paleoceanography,null,inductively-coupled plasma atomic emission spectroscopy,N,Polyspecific from >150 µm size fraction Trilobatus sacculifer from 250-355 µm size fraction earth science paleoclimate paleoceanography depth at sample start,null,null,centimeter,null,paleoceanography,null,null,N,null earth science paleoclimate paleoceanography delta 18O,Trilobatus sacculifer,null,per mil PDB,null,paleoceanography,null,null,N,250-350 µm size fraction earth science paleoclimate paleoceanography Globigerinoides ruber,null,null,count,null,paleoceanography,null,inductively-coupled plasma atomic emission spectroscopy,N,per foraminiferal classification; >150 µm size fraction earth science paleoclimate paleoceanography delta 18O,Trilobatus sacculifer,two standard deviations,per mil PDB,null,paleoceanography,null,null,N,null earth science paleoclimate paleoceanography planktic:benthic foraminifer,sediment,null,dimensionless,null,paleoceanography,null,null,N,null earth science paleoclimate paleoceanography depth at sample end,null,null,centimeter,null,paleoceanography,null,null,N,null earth science paleoclimate paleoceanography magnesium/calcium,Globigerinoides ruber|Orbulina universa|Trilobatus sacculifer,null,millimole per mole,null,paleoceanography,null,inductively-coupled plasma atomic emission spectroscopy,N,Polyspecific from >150 µm size fraction Trilobatus sacculifer from 250-355 µm size fraction earth science paleoclimate paleoceanography notes,null,null,null,null,paleoceanography,null,null,N,250-355 µm size fraction earth science paleoclimate paleoceanography total benthic foraminifers,sediment,null,count,null,paleoceanography,null,null,N,>150 µm size fraction earth science paleoclimate paleocean trace metals in carbonates earth science paleoclimate paleocean oxygen isotopes earth science paleoclimate paleocean radiogenic isotope earth science paleoclimate paleocean population abundance geoscientificInformation Complete 31.9282 31.9282 -75.7296 -75.7296 -2790 -2790 Ocean Atlantic Ocean North Atlantic Ocean CH15-00-PC9>LATITUDE 31.9282>LONGITUDE -75.7296 None Please cite original publication, online resource, dataset and publication DOIs (where available), and date accessed when using downloaded data. If there is no publication information, please cite investigator, title, online resource, and date accessed. The appearance of external links associated with a dataset does not constitute endorsement by the Department of Commerce/National Oceanic and Atmospheric Administration of external Web sites or the information, products or services contained therein. For other than authorized activities, the Department of Commerce/NOAA does not exercise any editorial control over the information you may find at these locations. These links are provided consistent with the stated purpose of this Department of Commerce/NOAA Web site. English DOC/NOAA/NESDIS/NCEI National Centers for Environmental Information, NESDIS, NOAA, U.S. Department of Commerce https://www.ncdc.noaa.gov/data-access/paleoclimatology-data DATA Center Contact Bruce Bauer bruce.a.bauer@noaa.gov paleo@noaa.gov 303-497-6280 303-497-6513

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Boulder CO 80305-3328 USA online ASCII Wycech, J., Kelly, D.C., and Marcott, S. 2016 Geology 44 7 551-554 10.1130/G37864.1

Radiocarbon (14C) ages obtained from planktic foraminiferal calcite are a mainstay for reconstructing ocean-climate change and carbon cycle dynamics of the past 30 thousand years, yet the effects of diagenesis on this vital chronometer are poorly constrained. Here, we address this shortcoming by comparing 14C ages and trace element ratios (Mg/Ca, Mn/Ca) of planktic foraminifera with white, opaque shells deemed well preserved by traditional standards to those with exquisitely preserved translucent shells. Results support a diagenetic mechanism as opaque shells yield 14C ages invariably older and trace element ratios consistently higher than those of translucent shells. Radiocarbon age offsets are particularly pronounced in mono-specific samples taken from stratigraphic horizons proximal to the d18O maximum marking the Last Glacial Maximum (LGM) and the subsequent deglacial. Radiocarbon-based calendar ages of translucent shells from the two intervals are congruent with the established age ranges for these climate events, whereas those of co-occurring opaque shells overestimate the LGM and deglacial by 8,000-15,000 yrs and 14,000-22,000 yrs, respectively. These results demonstrate that the use of translucent foraminifera enhances reproducibility and accuracy of 14C ages by minimizing the deleterious effects of diagenesis. This study serves as a cautionary tale since white, opaque foraminifera are common in pelagic sediments, and 14C ages derived from their ostensibly well-preserved shells can lead to discrepancies in the timing of Quaternary climate events and ocean circulation reconstructions. STUDY NOTES: Radiocarbon chronology, geochemistry, and abundance counts of foraminiferal shells for the upper 270 cm of a piston core from the Blake Ridge Provided Keywords: paleoceanography, radiocarbon, foraminifera, Quaternary, diagenesis

GET DATA https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/wycech2016/wycech2016-ch15-00-pc9-forams.txt Formatted Text File; CH15-00-PC9 T. sacculifer, Gs. ruber, and O. universa shell Data GET DATA https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/wycech2016/wycech2016-ch15-00-pc9-d18o.txt Formatted Text File; CH15-00-PC9 d18O Data GET DATA https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/wycech2016/wycech2016-ch15-00-pc9-pl-ben.txt Formatted Text File; CH15-00-PC9 Planktic and Benthic Foram Data GET DATA https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/wycech2016/wycech2016-ch15-00-pc9-chem.txt Formatted Text File; CH15-00-PC9 Geochemistry Data USA/NOAA DIF Version 9.8.4 2018-12-11 2018-12-11