noaa-ocean-17371 Eastern Equatorial Pacific Isotopic Ratios of Sr, Nd, and Pb and Nd Concentration Data over last 25,000 Years Xie, R.C.; Marcantonio, F. Eastern Equatorial Pacific Isotopic Ratios of Sr, Nd, and Pb and Nd Concentration Data over last 25,000 Years 2014-10-27 NCDC-Paleoclimatology ONLINE Files Pending https://www.ncdc.noaa.gov/paleo/study/17371 Investigator R.C. Xie Investigator F. Marcantonio earth science paleoclimate paleoceanography notes,null,null,null,null,paleoceanography,null,null,C,null earth science paleoclimate paleoceanography age,null,null,calendar kiloyear before present,null,paleoceanography,null,null,N,null earth science paleoclimate paleoceanography notes,null,null,null,null,paleoceanography,null,null,N,percent residual earth science paleoclimate paleoceanography 87Sr/86Sr,sediment,one standard error,dimensionless,null,paleoceanography,null,thermal ionization mass spectrometry,N,with DTPA earth science paleoclimate paleoceanography 208Pb/204Pb,sediment,null,dimensionless,null,paleoceanography,null,thermal ionization mass spectrometry,N,null earth science paleoclimate paleoceanography 207Pb/206Pb,sediment,null,dimensionless,null,paleoceanography,null,thermal ionization mass spectrometry,N,null earth science paleoclimate paleoceanography 208Pb/206Pb,sediment,null,dimensionless,null,paleoceanography,null,thermal ionization mass spectrometry,N,null earth science paleoclimate paleoceanography 207Pb/204Pb,sediment,null,dimensionless,null,paleoceanography,null,thermal ionization mass spectrometry,N,null earth science paleoclimate paleoceanography 87Sr/86Sr,sediment,null,dimensionless,null,paleoceanography,null,thermal ionization mass spectrometry,N,without DTPA earth science paleoclimate paleoceanography neodymium,sediment,null,milligram per kilogram,null,paleoceanography,null,inductively-coupled plasma atomic emission spectroscopy,N,bulk Nd earth science paleoclimate paleoceanography neodymium,sediment,null,percent,null,paleoceanography,null,null,N,in crust earth science paleoclimate paleoceanography 87Sr/86Sr,sediment,one standard error,dimensionless,null,paleoceanography,null,thermal ionization mass spectrometry,N,without DTPA earth science paleoclimate paleoceanography epsilon neodymium,sediment,null,epsilon unit,null,paleoceanography,null,thermal ionization mass spectrometry,N,null earth science paleoclimate paleoceanography 206Pb/204Pb,sediment,null,dimensionless,null,paleoceanography,null,thermal ionization mass spectrometry,N,null earth science paleoclimate paleoceanography 87Sr/86Sr,sediment,null,dimensionless,null,paleoceanography,null,thermal ionization mass spectrometry,N,with DTPA earth science paleoclimate paleocean geochemistry geoscientificInformation Intertropical Convergence Zone (ITCZ) 25000 cal yr BP 900 cal yr BP Complete -2.994083 7.210917 -110.57 -109.7513 -3860 -3714 Ocean Pacific Ocean Eastern Pacific Ocean ODP 850>LATITUDE 1.2972>LONGITUDE -110.5214 Ocean Pacific Ocean North Pacific Ocean ODP 849>LATITUDE .18>LONGITUDE -110.52 Ocean Atlantic Ocean North Atlantic Ocean ODP 851>LATITUDE 2.77>LONGITUDE -110.57 Ocean Pacific Ocean Eastern Pacific Ocean ODP 852>LATITUDE 5.292633>LONGITUDE -110.076067 Ocean Pacific Ocean Eastern Pacific Ocean ODP 848>LATITUDE -2.994083>LONGITUDE -110.479983 Ocean Pacific Ocean Eastern Pacific Ocean ODP 853>LATITUDE 7.210917>LONGITUDE -109.7513 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 Xie, R.C. and F. Marcantonio 2012 Earth and Planetary Science Letters 317 386-395 10.1016/j.epsl.2011.11.014

The provenance of eolian dust supplied to deep-sea sediments has the potential to offer insights into changes in past atmospheric circulation. Specifically, measuring temporal changes in dust provenance can shed light on changes in the mean position of the Intertropical Convergence Zone (ITCZ), a region acting as a barrier separating wind-blown material derived from northern versus southern hemisphere sources. Here we have analyzed Nd, Sr, and Pb isotope ratios in the operationally-defined detrital component extracted from deep-sea sediments in the eastern equatorial Pacific (EEP) along a meridional transect at 110°W from 3°S to 7°N (ODP Leg 138, sites 848–853). Sr isotope results show that barite Sr has a significant influence on 87Sr/86Sr isotope ratios of samples in the upwelling zone of the EEP. However, sites located >3° or more away from the equator (sites 852 and 853) are believed to not be affected by barite Sr and provide useful detrital Sr signals. 208Pb/206Pb and 207Pb/206Pb ratios in all cores fall into the Pb-isotope space of five potential dust sources (Asia, North and Central/South America, Sahara, and Australia), with no distinct isotopic fingerprinting of the dominant source(s). εNd values were most valuable for discerning detrital source provenance, and their values at all sites, ranging from −5.46 to −3.25, were more unradiogenic for sediments deposited during the last glacial than for those deposited during the Holocene. There are distinct latitudinal trends in the εNd values, with more radiogenic values further south and less radiogenic values further north, excluding site 848. This distinction holds true for both Holocene and last glacial periods. For the most southerly site, 848, we invoke, for the first time, a distinct southern hemisphere Australian source as being responsible for the unradiogenic Nd isotope ratios. Both average last glacial and Holocene εNd values show similar sharp gradients along the transect between 5.29°N and 2.77°N, suggesting little movement of the glacial ITCZ in the EEP. However, during the deglacial, this gradient is stronger and shifted further north between 5.29°N and 7.21°N, suggesting a more northerly, possibly stronger, deglacial ITCZ. STUDY NOTES: The provenance of eolian dust supplied to deep-sea sediments has the potential to offer insights into changes in past atmospheric circulation. Specifically, measuring temporal changes in dust provenance can shed light on changes in the mean position of the Intertropical Convergence Zone (ITCZ), a region acting as a barrier separating wind-blown material derived from northern versus southern hemisphere sources. Here we have analyzed Nd, Sr, and Pb isotope ratios in the operationally-defined detrital component extracted from deep-sea sediments in the eastern equatorial Pacific (EEP) along a meridional transect at 110°W from 3°S to 7°N (ODP Leg 138, sites 848 – 853). Sr isotope results show that barite Sr has a significant influence on 87Sr/86Sr isotope ratios of samples in the upwelling zone of the EEP. However, sites located >3° or more away from the equator (sites 852 and 853) are believed to not be affected by barite Sr and provide useful detrital Sr signals. 208Pb/206Pb and 207Pb/206Pb ratios in all cores fall into the Pb-isotope space of five potential dust sources (Asia, North and Central/South America, Sahara, and Australia), with no distinct isotopic fingerprinting of the dominant source(s). εNd values were most valuable for discerning detrital source provenance, and their values at all sites, ranging from -5.46 to -3.25, were more unradiogenic for sediments deposited during the last glacial than for those deposited during the Holocene. There are distinct latitudinal trends in the εNd values, with more radiogenic values further south and less radiogenic values further north, excluding site 848. This distinction hold s true for both Holocene and last glacial periods. For the most southerly site, 848, we invoke, for the first time, a distinct southern hemisphere Australian source as being responsible for the unradiogenic Nd isotope ratios. Both average last glacial and Holocene εNd values show similar sharp gradients along the transect between 5.29°N and 2.77°N, suggesting little movement of the glacial ITCZ in the EEP. However, during the deglacial, this gradient is stronger and shifted further north between 5.29°N to 7.21°N, suggesting a more northerly, possibly stronger, deglacial ITCZ. There are 6 cores in total in our study. Provided keywords: Radiogenic isotopes, Intertropical Convergence Zone, dust provenance

GET DATA https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/xie2012-epsl/xie2012-epsl-odp848.txt Formatted Text File; ODP848 Data GET DATA https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/xie2012-epsl/xie2012-epsl-odp849.txt Formatted Text File; ODP849 Data GET DATA https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/xie2012-epsl/xie2012-epsl-odp853.txt Formatted Text File; ODP853 Data GET DATA https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/xie2012-epsl/xie2012-epsl-odp851.txt Formatted Text File; ODP851 Data GET DATA https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/xie2012-epsl/xie2012-epsl-odp850.txt Formatted Text File; ODP850 Data GET DATA https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/xie2012-epsl/xie2012-epsl-odp852.txt Formatted Text File; ODP852 Data USA/NOAA DIF Version 9.8.4 2019-04-29 2019-04-29