Laurentian Slope Benthic Foraminiferal Mg/Ca, d18O, and Temperature Estimates ----------------------------------------------------------------------- World Data Center for Paleoclimatology, Boulder and NOAA Paleoclimatology Program ----------------------------------------------------------------------- NOTE: PLEASE CITE CONTRIBUTORS WHEN USING THIS DATA!!!!! NAME OF DATA SET: Laurentian Slope Benthic Foraminiferal Mg/Ca, d18O, and Temperature Estimates LAST UPDATE: 12/2003 (Original Receipt by WDC Paleo) CONTRIBUTORS: Thomas Marchitto and Peter deMenocal IGBP PAGES/WDCA CONTRIBUTION SERIES NUMBER: 2003-092 SUGGESTED DATA CITATION: Marchitto, T.M., and P.B. deMenocal, 2003, Laurentian Slope Benthic Foraminiferal Mg/Ca, d18O, and Temperature Estimates, IGBP PAGES/World Data Center for Paleoclimatology Data Contribution Series # 2003-092. NOAA/NGDC Paleoclimatology Program, Boulder CO, USA. ORIGINAL REFERENCE: Marchitto, T.M., and P.B. deMenocal. 2003. Late Holocene variability of upper North Atlantic Deep Water temperature and salinity. Geochemistry, Geophysics, Geosystems, 4(12), 1100, doi: 10.1029/2003GC000598. GEOGRAPHIC REGION: North Atlantic Ocean, Laurentian Slope PERIOD OF RECORD: 4,000 Years BP - present DESCRIPTION: Foraminiferal geochemical data from Laurentian Slope core KNR158-4-10MC/09GGC (44 deg. 50'N, 54 deg. 54' W, 1854m. depth). All depths given are composite, achieved by adding 8.25 cm to original GGC depths. Where temperature is calculated, only results from the linear equation (1) are given here. Data are: %CaCO3 [Fig 2] radiocarbon ages (G. bulloides) [Fig 2] Mg/Ca (C. pachyderma) [Fig 4a] Mg/Ca temperatures with ages [Fig 5] d18O (C. pachyderma and Uvigerina) [Fig 4] d18O(smow) (C. pachyderma and Uvigerina) [Fig 4a] temperature and salinity (C. pachyderma and Uvigerina) [Fig 6a] Rejected Mg/Ca measurements (n=3) are given at bottom of Mg/Ca list. d18O(smow) was calculated at each depth using the mean Mg/Ca temperature for that depth, and the mean d18O for each species, resulting in up to two results per depth. For temperatures and salinities given at end of file [Fig 6a], there is only one pair per depth (C. pachyderma and Uvigerina salinities were averaged) (depths are not listed). Note on 3-depth moving averages: Three-depth mean given for Mg/Ca is the mean of all individual measurements over a 3-depth interval. It is plotted this way in Figs. 4a and 5, but in Fig 4b it is inadvertently plotted as the mean of 3 means (i.e., a mean was first calculated for each depth, then the running mean was based on those 3 means) (the difference is minor). Three-depth means for d18O and d18O(smow) were calculated using this latter "3-mean" approach. UNITS: depth: cm age: yr or kyr BP Mg/Ca: mmol/mol d18O: per mil PDB T: C S: psu PRECISION: Mg/Ca: 0.018 mmol/mol d18O: 0.06 per mil ABSTRACT: Magnesium/calcium ratios in benthic foraminifera (Cibicidoides pachyderma) from a sediment core on the Laurentian Slope (1854 m) exhibit strong millennial-scale fluctuations during the past 4000 years. We convert these data to seawater paleotemperatures using a new monospecific linear equation. Results suggest that the temperature of upper North Atlantic Deep Water (dominated by Labrador Seawater today) has varied by at least 2C during the late Holocene. Millennial scale coolings coincide with previously identified periods of increased drift ice and regional glacier advances, including the Little Ice Age. Paired oxygen isotope measurements indicate that salinity and perhaps density were reduced during the cold periods. We discuss possible mechanisms for transmitting this cold, fresh signal from surface waters to intermediate depths. Our reconstructed late Holocene ranges in upper North Atlantic Deep Water properties greatly exceed those of the instrumental record and imply that large changes may be yet to come. DATA: 1. Radiocarbon dates CAMS# depth raw-14C-age14C-errocal-age-BP2s-cal-error 49756 0 240 40 0 0 80338 4.25 885 35 413 87 80339 16.25 1085 35 579 62 80340 24.25 1505 45 959 113 80332 36.5 2070 40 1533 124 80333 40.5 2040 35 1494 106 80334 47.5 2680 40 2240 102 80335 53.5 2995 35 2644 113 53936 63.5 3250 50 2942 156 80336 72.5 3875 35 3717 112 80337 79.5 4135 35 4055 133 53937 81.5 4370 60 4381 179 2. Geochemical data 10MC %CaCO3 09GGC %CaCO3 depth Mg/Ca depth Mg/Ca stderr cal-age 14C-age MeanT stderr+ stderr- Depth d18O depth d18O depth d18O Depth d18OSMOW depth d18SMOW depth d18OSMOW T theta salinity depth depth 3-mean KyrBP KYrBP 3-dep pachy Uvi 3mean pachy uvi 3mean 0.5 33.49 25.25 34.2 0.5 0.938 1.75 0.851 0.048 0.195 0.184 2.004 2.195 1.813 4.25 2.627 0.25 3.274 1.25 2.753 4.25 -0.237 2.25 -0.005 4.25 -0.028 1.748 1.628 34.258 1.5 34.15 27.25 33.6 1.75 0.842 2.25 0.802 0.021 0.238 0.223 1.807 1.89 1.724 9.5 2.815 1.25 3.276 2.25 2.744 12.25 0.033 4.25 -0.065 6.25 -0.017 2.364 2.235 34.301 2.5 34.24 29.25 33.3 2.25 0.773 2.75 0.735 0.046 0.276 0.26 1.541 1.727 1.356 10.25 2.628 2.25 3.27 3.25 2.739 14.25 -0.075 6.25 0.072 7.25 0.002 1.756 1.636 34.335 3.5 34.4 31.25 34.1 2.75 0.79 4.25 0.746 0.051 0.374 0.352 1.583 1.789 1.377 11.5 2.845 2.25 3.269 4.25 2.698 18.5 -0.057 7.25 0.027 8.25 -0.016 1.404 1.289 34.336 4.5 33.99 33.25 32.6 4.25 0.643 4.75 0.785 0.077 0.401 0.378 1.74 2.048 1.432 12.25 2.691 3.25 3.246 5.25 2.71 19.25 0.053 8.25 -0.094 11.25 -0.015 1.928 1.806 34.348 5.5 33.24 35.25 32.9 4.75 0.804 5.75 0.854 0.03 0.448 0.423 2.016 2.136 1.896 13.5 2.715 4.25 3.316 6.25 2.679 20.5 -0.021 11.25 0.019 12.25 -0.01 1.648 1.529 34.367 6.5 34.24 37.25 30.15 5.75 0.908 6.25 0.883 0.017 0.468 0.443 2.133 2.203 2.064 14.25 2.625 4.25 3.322 7.25 2.637 24.25 0.13 12.25 0.03 14.25 -0.028 2.076 1.951 34.393 7.5 34.15 37.25 29.6 6.25 0.85 6.75 0.89 0.023 0.486 0.462 2.16 2.25 2.07 15.5 2.545 5.25 3.145 8.25 2.619 24.5 -0.181 14.25 -0.085 18.25 -0.057 2.368 2.239 34.397 8.5 34.82 39.25 30.24 6.75 0.892 7.25 0.922 0.016 0.503 0.479 2.287 2.349 2.224 16.5 2.66 6.25 3.282 9.25 2.674 25.25 0.112 18.25 -0.036 18.5 -0.022 1.172 1.06 34.403 9.5 34.4 39.25 30.7 7.25 0.928 7.75 0.947 0.011 0.518 0.495 2.387 2.432 2.342 17.5 2.575 7.25 3.171 9.5 2.72 26.25 0.048 19.25 0.001 19.25 -0.017 2.352 2.223 34.432 10.5 34.57 41.25 31.32 7.75 0.945 8.25 0.895 0.061 0.532 0.509 2.181 2.425 1.937 18.5 2.746 8.25 3.013 10.25 2.71 28.25 0.15 22.25 0.171 20.5 0.059 2.26 2.133 34.443 11.5 34.32 41.25 31.3 8.25 0.967 8.75 0.938 0.088 0.545 0.523 2.352 2.702 2.002 19.25 2.655 8.25 3.022 11.25 2.72 28.5 0.081 23.25 0.171 22.25 0.107 2.168 2.042 34.452 12.5 34.32 43.25 32.74 8.75 0.774 9.75 0.93 0.087 0.567 0.548 2.319 2.665 1.973 19.5 2.445 9.25 3.228 11.5 2.738 29.25 -0.048 24.25 0.092 23.25 0.151 2.632 2.499 34.459 13.5 34.74 43.25 32.5 9.75 1.073 10.75 0.967 0.055 0.585 0.571 2.468 2.69 2.246 20.5 2.71 10.25 3.165 12.25 2.747 31.25 0.051 25.25 -0.007 24.25 0.034 2.496 2.365 34.467 14.5 34.9 45.25 31.65 10.75 0.942 11.25 0.905 0.018 0.594 0.581 2.221 2.295 2.148 21.5 2.595 11.25 3.199 13.25 2.704 31.5 0.077 25.5 -0.003 24.5 -0.006 2.468 2.337 34.472 15.5 35.49 45.25 33.1 11.25 0.886 12.25 0.868 0.019 0.609 0.601 2.073 2.148 1.999 22.5 2.715 12.25 3.208 13.5 2.681 32.25 0.19 26.25 0.01 25.25 -0.044 1.952 1.829 34.489 16.5 34.99 47.25 32.24 12.25 0.888 12.75 0.954 0.096 0.616 0.611 2.415 2.797 2.032 24.25 2.587 13.25 3.228 14.25 2.65 32.5 0.137 27.5 -0.11 25.5 0.026 2.504 2.373 34.49 17.5 34.99 47.25 32.5 12.75 0.831 13.75 0.937 0.103 0.631 0.631 2.348 2.758 1.938 24.5 2.583 14.25 3.135 15.25 2.593 33.5 -0.271 31.5 -0.026 26.25 -0.028 2.304 2.176 34.495 18.5 34.32 49.25 32.24 13.75 1.142 14.25 1.001 0.088 0.637 0.64 2.604 2.958 2.25 25.25 2.605 15.25 3.134 15.5 2.598 36.5 0.074 33.5 -0.271 27.5 0.023 2.716 2.582 34.508 19.5 34.49 49.25 32.4 14.25 0.838 14.75 0.86 0.089 0.645 0.65 2.039 2.394 1.684 26.25 2.668 16.25 3.154 16.25 2.613 40.5 0.014 35.5 -0.156 28.25 0.04 2.24 2.113 34.508 20.5 34.4 51.25 31.15 14.75 1.023 15.75 0.883 0.089 0.659 0.671 2.131 2.486 1.775 26.5 2.612 17.25 3.199 16.5 2.657 44.5 -0.118 37.5 -0.002 28.5 0.061 1.464 1.348 34.517 21.5 34.82 51.25 31.3 15.75 0.718 16.75 0.864 0.075 0.675 0.692 2.055 2.354 1.755 28.25 2.603 18.25 3.113 17.25 2.638 48.5 -0.207 41.5 -0.104 29.25 0.028 2.216 2.089 34.527 22.5 34.49 53.25 30.82 16.75 0.907 17.75 0.932 0.018 0.691 0.715 2.328 2.398 2.258 28.5 2.691 19.25 3.123 17.5 2.615 50.5 -0.065 45.5 -0.196 31.25 0.009 2.628 2.495 34.54 23.5 34.57 53.25 30.6 17.75 0.966 18.25 0.868 0.077 0.701 0.728 2.073 2.382 1.765 29.25 2.596 20.25 3.169 18.25 2.638 56.5 -0.023 31.5 0.089 2.292 2.164 34.542 24.5 33.99 55.25 30.82 18.25 0.923 18.5 0.834 0.062 0.705 0.734 1.937 2.184 1.691 30.5 2.547 21.25 3.135 18.5 2.656 57.5 -0.079 32.25 0.118 2.766 2.631 34.543 25.5 33.9 55.25 30.9 18.5 0.716 18.75 0.845 0.07 0.71 0.74 1.98 2.259 1.701 31.25 2.542 22.25 3.135 19.25 2.607 58.5 0.234 32.5 0.019 2.552 2.42 34.558 26.5 33.99 57.25 30.49 18.75 0.864 19.25 0.902 0.027 0.72 0.753 2.208 2.317 2.099 31.5 2.6 23.25 3.103 19.5 2.574 59.5 -0.038 33.5 -0.097 1.804 1.683 34.56 27.5 33.49 57.25 30.9 19.25 0.955 19.75 0.881 0.045 0.731 0.767 2.124 2.302 1.946 32.25 2.605 24.25 3.069 20.25 2.601 60.5 0.287 35.5 -0.118 1.692 1.572 34.58 28.5 33.57 59.25 31.07 19.75 0.887 20.5 0.909 0.069 0.748 0.788 2.235 2.512 1.958 32.5 2.666 25.25 3.007 20.5 2.658 62.5 0.033 36.5 -0.028 2.336 2.207 34.582 29.5 32.99 59.25 31 20.5 0.801 20.75 0.954 0.077 0.754 0.796 2.417 2.724 2.11 33.5 2.472 25.5 3.136 21.25 2.64 65.5 -0.127 37.5 0.029 2.516 2.384 34.584 30.5 32.99 61.25 30.65 20.75 1.038 21.75 1.068 0.038 0.78 0.827 2.873 3.024 2.723 34.5 2.587 26.25 3.15 21.5 2.608 66.5 -0.206 40.5 -0.031 3.084 2.944 34.602 31.5 33.07 61.25 31.2 21.75 1.024 22.25 1.082 0.034 0.794 0.843 2.928 3.066 2.79 36.5 2.679 27.5 3.064 22.25 2.642 68.5 0.035 41.5 -0.07 2.144 2.018 34.609 32.5 32.74 63.25 31.2 22.25 1.143 22.75 1.134 0.03 0.808 0.86 3.137 3.256 3.018 38.5 2.727 31.5 3.016 22.5 2.638 69.5 -0.099 44.5 -0.14 2.796 2.66 34.616 33.5 32.74 65.25 28.66 22.75 1.079 23.25 1.049 0.086 0.824 0.878 2.797 3.141 2.454 40.5 2.476 33.5 2.992 23.25 2.622 70.5 -0.065 45.5 -0.174 2.312 2.183 34.618 65.25 29.7 23.25 1.181 23.75 1.081 0.07 0.839 0.896 2.925 3.204 2.646 42.5 2.505 35.5 2.976 24.25 2.578 72.5 -0.159 48.5 -0.156 2.42 2.29 34.618 67.25 28.16 23.75 0.888 24.25 0.977 0.094 0.856 0.915 2.506 2.883 2.129 44.5 2.517 37.5 3.1 24.5 2.566 73.5 -0.235 50.5 -0.098 2.904 2.767 34.62 67.25 29 24.25 1.186 24.5 1.03 0.092 0.865 0.924 2.718 3.088 2.348 46.5 2.482 41.5 2.973 25.25 2.582 74.5 0.213 56.5 -0.056 2.336 2.207 34.621 69.25 28.99 24.25 1.07 24.75 0.982 0.11 0.873 0.934 2.528 2.968 2.088 48.5 2.534 45.5 3.029 25.5 2.604 75.5 0.189 57.5 0.044 2.152 2.025 34.623 69.25 29.1 24.5 0.762 25.25 1.039 0.053 0.891 0.954 2.757 2.969 2.546 50.5 2.575 26.25 2.626 76.5 0.029 58.5 0.039 2.596 2.463 34.626 71.25 27.99 24.75 1.1 25.5 1.007 0.043 0.901 0.964 2.628 2.801 2.455 52.5 2.59 26.5 2.602 77.5 -0.075 59.5 0.161 2.5 2.369 34.628 71.25 28.1 25.25 1.084 25.75 0.951 0.023 0.91 0.974 2.405 2.499 2.311 54.5 2.485 27.5 2.587 78.5 0.319 60.5 0.094 2.948 2.81 34.647 73.25 28.49 25.5 0.934 26.25 0.976 0.03 0.93 0.995 2.505 2.624 2.386 56.5 2.551 28.25 2.613 79.5 -0.035 62.5 0.064 2.936 2.798 34.649 73.25 28.9 25.75 1.003 26.75 0.949 0.034 0.95 1.016 2.394 2.53 2.258 57.5 2.505 28.5 2.63 65.5 -0.1 2 1.875 34.673 75.25 28.16 26.25 0.895 27.5 0.927 0.055 0.981 1.049 2.308 2.526 2.09 58.5 2.706 29.25 2.611 66.5 -0.099 2.404 2.274 34.675 75.25 28.2 26.25 0.973 27.75 0.96 0.087 0.992 1.061 2.439 2.786 2.091 59.5 2.52 30.5 2.562 68.5 -0.09 2.38 2.25 34.683 77.25 26.74 26.75 1.034 28.25 0.977 0.082 1.014 1.084 2.509 2.836 2.183 60.5 2.675 31.25 2.546 69.5 -0.043 3.112 2.972 34.72 77.25 27.5 27.5 0.892 28.5 1.021 0.057 1.026 1.095 2.685 2.912 2.459 62.5 2.598 31.5 2.565 70.5 -0.107 2.768 2.632 34.751 79.25 27.32 27.75 0.855 28.75 0.945 0.024 1.037 1.107 2.381 2.477 2.285 64.5 2.589 32.25 2.606 72.5 -0.153 3.128 2.987 34.766 79.25 28.2 28.25 1.132 29.25 0.97 0.034 1.061 1.131 2.479 2.615 2.343 65.5 2.489 32.5 2.581 73.5 -0.06 3.324 3.181 34.792 81.25 28.8 28.5 0.945 29.75 0.945 0.037 1.085 1.155 2.38 2.526 2.234 66.5 2.609 33.5 2.575 74.5 0.056 3.172 3.031 34.792 83.25 27.24 28.75 0.987 30.25 0.965 0.03 1.109 1.18 2.461 2.583 2.34 68.5 2.62 34.5 2.505 75.5 0.144 3.54 3.393 34.813 83.25 27 29.25 0.904 30.75 0.988 0.052 1.135 1.205 2.553 2.76 2.347 69.5 2.487 35.5 2.574 76.5 0.048 3.312 3.169 34.815 85.25 26.66 29.75 1.018 31.25 1.034 0.036 1.16 1.23 2.735 2.879 2.59 70.5 2.475 36.5 2.572 77.5 0.091 3.18 3.038 34.842 85.25 27.6 30.25 0.913 31.5 1.052 0.02 1.174 1.243 2.807 2.885 2.728 72.5 2.515 37.5 2.662 78.5 0.07 3.04 2.9 34.868 87.25 27.16 30.75 0.965 31.75 1.082 0.049 1.187 1.256 2.928 3.123 2.733 73.5 2.379 38.5 2.594 3.436 3.291 34.93 87.25 27.6 31.25 1.087 32.25 1.08 0.05 1.214 1.282 2.919 3.117 2.72 74.5 2.655 40.5 2.552 4.172 4.016 34.969 31.5 1.049 32.5 1.065 0.06 1.227 1.295 2.859 3.099 2.619 75.5 2.556 41.5 2.478 31.75 1.019 33.25 0.934 0.076 1.269 1.335 2.337 2.642 2.032 76.5 2.529 42.5 2.492 32.25 1.178 33.5 0.901 0.058 1.283 1.349 2.204 2.435 1.973 77.5 2.551 44.5 2.51 32.5 1.042 35.5 0.893 0.053 1.4 1.458 2.173 2.386 1.96 78.5 2.553 45.5 2.503 33.25 0.974 36.5 0.957 0.011 1.461 1.514 2.429 2.474 2.385 79.5 2.494 46.5 2.508 33.5 0.787 37.5 0.967 0.008 1.522 1.57 2.468 2.501 2.435 80.5 2.393 48.5 2.53 35.5 0.942 39.5 1.024 0.049 1.649 1.683 2.695 2.89 2.5 86.5 2.495 50.5 2.566 36.5 0.951 40.5 1.033 0.045 1.713 1.739 2.733 2.914 2.553 114.5 2.578 52.5 2.55 37.5 0.979 41.5 1.015 0.06 1.778 1.795 2.659 2.897 2.42 122.5 2.547 54.5 2.542 39.5 0.971 44.5 0.918 0.051 1.972 1.961 2.273 2.477 2.07 56.5 2.514 40.5 1.121 45.5 0.837 0.043 2.037 2.015 1.949 2.123 1.776 57.5 2.587 41.5 1.008 47.5 0.795 0.02 2.165 2.121 1.781 1.86 1.703 58.5 2.577 44.5 0.915 48.5 0.899 0.122 2.228 2.173 2.196 2.685 1.707 59.5 2.634 45.5 0.832 49.5 0.947 0.104 2.29 2.224 2.389 2.805 1.974 60.5 2.598 47.5 0.765 50.5 0.973 0.086 2.352 2.273 2.492 2.836 2.148 62.5 2.621 48.5 0.789 51.5 0.907 0.023 2.413 2.322 2.229 2.322 2.137 64.5 2.559 49.5 1.143 53.5 0.933 0.036 2.532 2.418 2.333 2.476 2.19 65.5 2.562 50.5 0.91 56.5 0.97 0.012 2.704 2.555 2.48 2.53 2.43 66.5 2.573 51.5 0.866 57.5 1.025 0.043 2.76 2.6 2.699 2.87 2.527 68.5 2.572 53.5 0.946 58.5 1.031 0.041 2.815 2.645 2.724 2.886 2.562 69.5 2.527 56.5 0.988 59.5 1.109 0.058 2.869 2.689 3.035 3.268 2.801 70.5 2.492 57.5 0.976 60.5 1.008 0.116 2.924 2.733 2.631 3.095 2.166 72.5 2.456 58.5 1.11 61.5 1.005 0.116 2.978 2.776 2.62 3.084 2.156 73.5 2.516 59.5 1.007 62.5 0.868 0.066 3.031 2.821 2.072 2.334 1.81 74.5 2.53 60.5 1.209 63.5 0.912 0.059 3.085 2.865 2.247 2.485 2.009 75.5 2.58 61.5 0.807 65.5 0.812 0.069 3.194 2.955 1.849 2.124 1.574 76.5 2.545 62.5 0.999 66.5 0.871 0.086 3.249 3.001 2.085 2.429 1.742 77.5 2.544 63.5 0.798 68.5 0.883 0.091 3.362 3.097 2.133 2.498 1.769 78.5 2.533 65.5 0.938 69.5 0.993 0.018 3.421 3.146 2.571 2.643 2.498 79.5 2.48 66.5 0.701 70.5 0.957 0.047 3.481 3.196 2.429 2.617 2.242 68.5 0.975 72.5 0.946 0.046 3.608 3.302 2.385 2.57 2.2 69.5 0.974 73.5 1.025 0.071 3.675 3.356 2.7 2.983 2.417 70.5 1.029 74.5 1.14 0.058 3.745 3.413 3.161 3.393 2.928 72.5 0.869 75.5 1.167 0.038 3.818 3.47 3.269 3.419 3.118 73.5 0.941 76.5 1.118 0.079 3.894 3.529 3.072 3.39 2.754 74.5 1.139 77.5 1.132 0.138 3.974 3.59 3.127 3.677 2.576 74.5 1.151 78.5 1.101 0.101 4.057 3.651 3.002 3.408 2.596 75.5 1.305 75.5 1.165 76.5 1.076 77.5 0.926 78.5 1.393 79.5 1.059 79.5 1.024 rejects 10.25 1.732 25.25 1.512 27.25 1.565