noaa-ocean-20439 North Atlantic (DSDP 607) Geochemistry Data and BWT Reconstruction during the Mid-Pleistocene Transition Ford, H.L.; Sosdian, S.M.; Rosenthal, Y.; Raymo, M.E. North Atlantic (DSDP 607) Geochemistry Data and BWT Reconstruction during the Mid-Pleistocene Transition 2016-08-24 NCDC-Paleoclimatology ONLINE Files Pending https://www.ncdc.noaa.gov/paleo/study/20439 Investigator H.L. Ford Investigator S.M. Sosdian Investigator Y. Rosenthal Investigator M.E. Raymo earth science paleoclimate paleoceanography depth,null,null,meter,null,paleoceanography,composited,null,N,null earth science paleoclimate paleoceanography delta 18O,benthic foraminifer,null,per mil PDB,null,paleoceanography,corrected,null,N,adjusted to Uvigerina sp. comparable values earth science paleoclimate paleoceanography titanium/calcium,Uvigerina sp.,null,micromole per mole,null,paleoceanography,null,null,N,null 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 iron/calcium,Uvigerina sp.,null,micromole per mole,null,paleoceanography,null,null,N,null earth science paleoclimate paleoceanography sample identification,null,null,null,null,paleoceanography,null,null,C,null earth science paleoclimate paleoceanography aluminum/calcium,Uvigerina sp.,null,micromole per mole,null,paleoceanography,null,null,N,null earth science paleoclimate climate reconstructions|paleoceanography sea water temperature,magnesium/calcium,null,degree Celsius,null,climate reconstructions|paleoceanography,null,null,N,deepwater temperature using Uvigerina spp. earth science paleoclimate climate reconstructions|paleoceanography delta 18O,delta 18O|magnesium/calcium|sea water,null,per mil SMOW,null,climate reconstructions|paleoceanography,null,null,N,null earth science paleoclimate paleoceanography magnesium/calcium,Uvigerina sp.,null,millimole per mole,null,paleoceanography,null,null,N,null earth science paleoclimate paleoceanography manganese/calcium,Uvigerina sp.,null,micromole per mole,null,paleoceanography,null,null,N,null earth science paleoclimate paleocean geochemistry earth science paleoclimate paleocean oxygen isotopes earth science paleoclimate paleocean reconstruction geoscientificInformation 1500000 cal yr BP 500000 cal yr BP Complete 41.000019 41.000019 -32.950122 -32.950122 -3427 -3427 Ocean Atlantic Ocean North Atlantic Ocean DSDP 607>LATITUDE 41.000019>LONGITUDE -32.950122 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 Ford, H.L., S.M. Sosdian, Y. Rosenthal, and M.E. Raymo 2016 Quaternary Science Reviews 148 222-233 10.1016/j.quascirev.2016.07.005

During the Mid-Pleistocene Transition (MPT), the dominant glacial-interglacial cyclicity as inferred from the marine d18O records of benthic foraminifera (d18Obenthic) changed from 41 kyr to 100 kyr years in the absence of a comparable change in orbital forcing. Currently, only two Mg/Ca-derived, high-resolution bottom water temperature (BWT) records exist that can be used with d18Obenthic records to separate temperature and ice volume signals over the Pleistocene. However, these two BWT records suggest a different pattern of climate change occurred over the MPTda record from North Atlantic DSDP Site 607 suggests BWT decreased with no long-term trend in ice volume over the MPT, while South Pacific ODP Site 1123 suggests that BWT has been relatively stable over the last 1.5 Myr but that there was an abrupt increase in ice volume at ~900 kyr. In this paper we attempt to reconcile these two views of climate change across the MPT. Specifically, we investigated the suggestion that the secular BWT trend obtained from Mg/Ca measurements on Cibicidoides wuellerstorfi and Oridorsalis umbonatus species from N. Atlantic Site 607 is biased by the possible influence of D[CO3 2_] on Mg/Ca values in these species by generating a low-resolution BWT record using Uvigerina spp., a genus whose Mg/Ca values are not thought to be influenced by D[CO3 2_]. We find a long-term BWT cooling of ~2e3_C occurred from 1500 to ~500 kyr in the N. Atlantic, consistent with the previously generated C. wuellerstorfi and O. umbonatus BWT record. We also find that changes in ocean circulation likely influenced d18Obenthic, BWT, and d18Oseawater records across the MPT. N. Atlantic BWT cooling starting at ~1.2 Ma, presumably driven by high-latitude cooling, may have been a necessary precursor to a threshold response in climate-ice sheet behavior at ~900 ka. At that point, a modest increase in ice volume and thermohaline reorganization may have caused enhanced sensitivity to the 100 kyr orbital cycle. STUDY NOTES: DSDP 607 minor element and derived d18Oseawater records from Uvigerina spp. Provided Keywords: Mid-Pleistocene Transition, Mg/Ca, Uvigerina spp.

GET DATA https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/ford2016/ford2016.txt Formatted Text File; DSDP 607 Data USA/NOAA DIF Version 9.8.4 2019-05-06 2019-05-06