noaa-ocean-25410 Measurements of d18O on the Planktic Foraminifer Trilobatus sacculifer from different ocean basins Wycech, J.; Kelly, D.C.; Kitajima, K.; Kozdon, R.; Orland, I.J.; Valley, J.W. Measurements of d18O on the Planktic Foraminifer Trilobatus sacculifer from different ocean basins 2018-10-12 NCDC-Paleoclimatology ONLINE Files Pending https://www.ncdc.noaa.gov/paleo/study/25410 Investigator J. Wycech Investigator D.C. Kelly Investigator K. Kitajima Investigator R. Kozdon Investigator I.J. Orland Investigator J.W. Valley earth science paleoclimate paleocean oxygen isotopes geoscientificInformation 10000 cal yr BP 0 cal yr BP Complete .066667 31.9282 -75.7296 159.361 Geographic Region Global Ocean PC9, 806, A2, and EqPac>LATITUDE >LONGITUDE 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.B., Kelly, D.C., Kitajima, K., Kozdon, R., Orland, I.J., and Valley, J.W. 2018 Geochemistry, Geophysics, Geosystems 18 2 1-15 10.1029/2018GC007908

Oxygen isotope ratios (d18O) measured from planktic foraminifer shells are commonly used to reconstruct past surface-ocean conditions, yet the shells of many planktic foraminifers are an aggregate mixture of multiple carbonate phases with differing d18O compositions. Here we demonstrate how secondary ion mass spectrometry (SIMS) can be used to measure intra-shell d18O heterogeneity by performing in situ analyses on micrometer-scale (3-10 μm) domains within individual shells of the extant, mixed layer species Trilobatus sacculifer. SIMS measurements on shells taken from Holocene-aged sediments at three sites in different ocean basins confirm that the d18O of gametogenic (GAM) calcite added to shells during the terminal (reproductive) stage of the life cycle is 1.0-1.4‰ higher than that of pre-gametogenic (PREGAM) calcite. Examination of shells in cross-section reveals that many have suffered varying degrees of internal dissolution, which further skews whole-shell d18O compositions toward higher values by preferentially removing low d18O PREGAM calcite. The results of this study echo the calls of earlier studies cautioning that spatiotemporal changes in the proportion of high d18O GAM calcite should be considered when assessing T. sacculifer d18O records generated via conventional isotope ratio mass spectrometry. STUDY NOTES: Provided Keywords: paleoceanography, foraminifera, oxygen isotopes, ion microprobe

GET DATA https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/wycech2018/wycech2018.txt NOAA Template File; Trilobatus sacculifer Data USA/NOAA DIF Version 9.8.4 2019-05-23 2019-05-23