Brazil Margin LGM and Holocene Benthic Foraminiferal Cadmium Data ----------------------------------------------------------------------- World Data Center for Paleoclimatology, Boulder and NOAA Paleoclimatology Program ----------------------------------------------------------------------- NOTE: PLEASE CITE ORIGINAL REFERENCE WHEN USING THIS DATA!!!!! NAME OF DATA SET: Brazil Margin LGM and Holocene Benthic Foraminiferal Cadmium Data LAST UPDATE: 2/2011 (Original receipt by WDC Paleo) CONTRIBUTORS: Makou, M.C., D.W. Oppo, and W.B. Curry IGBP PAGES/WDCA CONTRIBUTION SERIES NUMBER: 2011-020 WDC PALEO CONTRIBUTION SERIES CITATION: Makou, M.C., et al. 2011. Brazil Margin LGM and Holocene Benthic Foraminiferal Cadmium Data. IGBP PAGES/World Data Center for Paleoclimatology Data Contribution Series # 2011-021. NOAA/NCDC Paleoclimatology Program, Boulder CO, USA. ORIGINAL REFERENCE: Makou, M.C., D.W. Oppo, and W.B. Curry. 2010. South Atlantic intermediate water mass geometry for the last glacial maximum from foraminiferal Cd/Ca. Paleoceanography 25, PA4101, doi:10.1029/2010PA001962. ABSTRACT: Paleoceanographic studies using benthic foraminiferal Cd as a nutrient tracer have provided a robust means of reconstructing glacial Atlantic Ocean water mass geometry, but a paucity of data from the South Atlantic above 1200 m has limited investigation of Antarctic Intermediate Water (AAIW) configuration and formation. A new Cd depth profile from Brazil margin sediments suggests that AAIW penetrated northward at 1100 m to at least 27°S in the glacial Atlantic. It exhibited substantially reduced d13Cas values, confirming preliminary evidence that this AAIW was unique to the glacial Atlantic and that it formed differently than today, with less atmospheric contact. ADDITIONAL REFERENCES: Curry, W.B. and D.W. Oppo. 2005. Glacial water mass geometry and the distribution of d13C of SCO2 in the western Atlantic Ocean. Paleoceanography, 20, PA1017, doi:10.1029/2004PA001021. Lynch-Stieglitz, J., A. van Geen, and R.G. Fairbanks. 1996. Interocean exchange of Glacial North Atlantic Intermediate Water: Evidence from subantarctic Cd/Ca and carbon isotope measurements. Paleoceanography, 11(2), 191-201, doi:10.1029/95PA03772. Marchitto, T.M. and W.S. Broecker. 2006. Deep water mass geometry in the glacial Atlantic Ocean: A review of constraints from the paleonutrient proxy Cd/Ca. Geochem. Geophys. Geosyst., 7(12), Q12003, doi:10.1029/2006GC001323. Oppo, D.W. and M. Horowitz. 2000. Glacial deep water geometry: South Atlantic benthic foraminiferal Cd/Ca and d13C evidence. Paleoceanography, 15(2), 147-160, doi:10.1029/1999PA000436. GEOGRAPHIC REGION: Western South Atlantic PERIOD OF RECORD: Last Glacial Maximum (~21KYrBP) and modern DESCRIPTION: Benthic foraminiferal Cd results for a Brazil margin sediment depth transect. Data are provided for the last glacial maximum (LGM) and core top sediments. Individual core locations, sample depths, and the type of foraminifera used are provided, and Cd composition is reported as Cd/Ca and CdW. Foraminiferal carbon isotopic results from previous investigations were used to calculate the portion of the carbon isotopic signal arising from air/sea exchange (d13Cas) of carbon dioxide (see references in cited publication). The reported water depths have not been corrected for reduced LGM sea level. Core top Cd and d13Cas results for cores 10 GGC and 33 GGC are considered erroneous because relative standard deviations for multiple analyses were > 20%. See Makou et al. 2010 for further discussion of the results. DATA: Table 1. Brazil Margin Sediment Cores Used in This Study and LGM Sample Analytical Results Latitude Longitude Depth*a SampleDepth Cdw d13C*b d13Cas*c Core °S °W m cm. Foraminifera Cd/Ca nmol/kg ‰ ‰ 14 GGC 26°40.84' 46°26.92' 441 168.5 Uvigerina spp. 0.033 0.25 1.03 0.14 14 GGC 26°40.84' 46°26.92' 441 176.5 Uvigerina spp. 0.014 0.11 1.07 -0.5 137 JPC 26°41.39' 46°20.65' 462 56.5 Uvigerina spp. 0.019 0.15 1.31 -0.06 10 GGC 26°28.86' 45°55.64' 630 100.5 C. pachyderma 0.03 0.23 1.03 0.03 99 GGC 27°22.15' 46°50.63' 790 80 C. pachyderma 0.037 0.29 0.5 -0.27 153 JPC 26°23.47' 45°41.69' 898 40.5 C. pachyderma 0.048 0.37 0.46 -0.12 38 JPC 27°15.97' 46°37.90' 936 32.5 H. elegans 0.048 0.48 0.54 0.22 38 JPC 27°15.97' 46°37.90' 936 40.5 H. elegans 0.053 0.53 0.5 0.3 90 GGC 27°21.00' 46°37.89' 1105 144.5 H. elegans 0.061 0.61 0.38 0.38 105 JPC 27°21.00' 46°37.79' 1108 48 C. pachyderma 0.077 0.59 0.36 0.3 105 JPC 27°21.00' 46°37.79' 1108 40 C. pachyderma 0.062 0.48 0.26 -0.06 36 GGC 27°15.16' 46°28.22' 1268 148 H. elegans 0.042 0.42 0.53 0.06 36 GGC 27°15.16' 46°28.22' 1268 152 H. elegans 0.042 0.42 0.64 0.17 95 JPC 27°31.64' 46°33.15' 1485 24.5 H. elegans 0.036 0.36 0.86 0.24 17 JPC 27°41.83' 46°29.64' 1627 64 H. elegans 0.02 0.2 0.92 -0.22 *a Not corrected for reduced LGM sea level. *b From Oppo and Horowitz [2000] and Curry and Oppo [2005]. *c Determined using the LGM equations of Lynch-Stieglitz et al. [1996] and Marchitto and Broecker [2006], which include whole-ocean d13C corrections Table 2. Brazil Margin Holocene Sediment Analytical Results Core Depth SampleDepth Foraminifera Cd/Ca CdW d13C*a d13Cas *b (m) (cm) (nmol/kg) (‰) (‰) 10 GGC 630 0.5 C. pachyderma 0.031 0.24*c 1.56 0.12*c 152 GGC 899 0.5 C. pachyderma 0.092 0.71 1.39 1.34 37 GGC 938 0.5 C. pachyderma 0.157 1.21 1.39 2.7 90 GGC 1105 0.5 C. pachyderma 0.053 0.41 1.27 0.39 105 JPC 1108 0 Uvigerina spp. 0.076 0.58 1.11 0.71 94 GGC 1490 0 C. pachyderma 0.108 0.68 1.1 0.96 33 GGC 2082 8.5 C. pachyderma 0.05 0.24*c 1.11 -0.34*c 73 GGC 2397 0 C. pachyderma 0.038 0.16 1.08 -0.77 *a Holocene results from Oppo and Horowitz [2000] and Curry and Oppo [2005]. d13C results are not from the same samples in which Cd was measured (and in some cases are from different cores within 77 m water depth). *b Determined using the modern seawater equations of Lynch?Stieglitz et al. [1996] and Marchitto and Broecker [2006]. Holocene d13Cas values are considered estimates because d13C results are not from the same samples in which Cd was measured. *c These Cd results exhibited RSDs > 20% and are thus likely erroneous. d13Cas values calculated from these results are similarly considered invalid.