# Holocene sedimentary radiogenic nuclide and sortable silt records from the Carolina Slope #----------------------------------------------------------------------- # World Data Service for Paleoclimatology, Boulder # and # NOAA Paleoclimatology Program #----------------------------------------------------------------------- # Template Version 3.0 # Encoding: UTF-8 # NOTE: Please cite original publication, online resource and date accessed when using this data. # If there is no publication information, please cite Investigator, title, online resource and date accessed. # # Description/Documentation lines begin with # # Data lines have no # # # Online_Resource: https://www.ncdc.noaa.gov/paleo/study/26330 # Description: NOAA Landing Page # Online_Resource: http://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/hoffmann2018/hoffmann2018-radiogenic.txt # Description: NOAA location of the template # # Data_Type: Paleoceanography # # Dataset_DOI: # # Parameter_Keywords: radiogenic isotope, geochemistry, physical properties #--------------------------------------- # Contribution_Date # Date: 2019-03-05 #--------------------------------------- # File_Last_Modified_Date # Date: 2019-03-05 #--------------------------------------- # Title # Study_Name: Holocene sedimentary radiogenic nuclide and sortable silt records from the Carolina Slope #--------------------------------------- # Investigators # Investigators: Hoffmann, S.S.; McManus, J.F.; Swank, E. #--------------------------------------- # Description_Notes_and_Keywords # Description: # Provided Keywords: Holocene, sediment geochemistry, sediment grain size #--------------------------------------- # Publication # Authors: Hoffmann, S.S., J.F. McManus, and E. Swank # Published_Date_or_Year: 2018 # Published_Title: Evidence for stable Holocene basin-scale overturning circulation despite variable currents along the Deep Western Boundary Current of the North Atlantic Ocean # Journal_Name: Geophysical Research Letters # Volume: 45 # Edition: # Issue: 24 # Pages: 13427-13436 # Report_Number: # DOI: 10.1029/2018GL080187 # Online_Resource: # Full_Citation: # Abstract: While substantial changes in thermohaline circulation related to deglacial climate variability are well established, the role of this circulation in Holocene climate variability remains uncertain. Here we use two dynamical proxies, 231Pa/230Th ratios and mean sortable silt size (SS), to reconstruct Holocene bottom water circulation at the intermediate-depth Carolina Slope. We find no substantial change in deep current speed or 231Pa export at this site during the Holocene, suggesting consistent 231Pa export via the Deep Western Boundary Current. SS shows increasing millennial-scale variability in the middle-late Holocene, which may reflect Labrador Sea Water contribution to current speed. We conclude that deepwater export from the North Atlantic has remained remarkably stable during the Holocene, decoupled from changing rates of specific water masses, while production of these water masses varied at millennial to centennial time scales. The persistence of the large-scale overturning may reflect the ocean's stabilizing influence on Holocene climate. #--------------------------------------- # Funding_Agency # Funding_Agency_Name: National Science Foundation # Grant: AGS 16-35019 #--------------------------------------- # Funding_Agency # Funding_Agency_Name: University of North Carolina Wilmington # Grant: Charles Cahill Award #--------------------------------------- # Funding_Agency # Funding_Agency_Name: Columbia University # Grant: Columbia Science Fellows Program #--------------------------------------- # Site_Information # Site_Name: KN140-2-51 # Location: North Atlantic Ocean # Country: # Northernmost_Latitude: 32.78 # Southernmost_Latitude: 32.78 # Easternmost_Longitude: -76.283 # Westernmost_Longitude: -76.283 # Elevation: -1790 #--------------------------------------- # Data_Collection # Collection_Name: KN140-2-51GGC radiogenic Hoffmann2018 # First_Year: 11190 # Last_Year: 90 # Time_Unit: cal yr BP # Core_Length: 4.29 # Notes: #--------------------------------------- # Chronology_Information # Chronology: # # Labcode sample identification used by 14C laboratory # depth Depth top of sample interval (cm) # species Foraminifera species dated # 14C_age conventional radiocarbon age, years before 1950AD # 14C_age_error radiocarbon age, standard error # calib_age Calibrated age # calib_age_error Calibrated age 1-sigma error # notes Sources for radiocarbon dates # # Labcode depth species 14C_age 14C_age_error calib_age calib_age_error notes # OS-50126 4 Mixed planktonics 615 35 263 50.5 Rasmussen & Thomsen (2012) # OS-125307 9 G. ruber 855 20 485 18.25 this study # OS-50127 100 G. sacculifer 3930 45 3915 69.25 Rasmussen & Thomsen (2012) # OS-50128 210 G. sacculifer 7310 55 7772 60.25 Rasmussen & Thomsen (2012) # OS-95767 222 G. ruber 7980 45 8438 47.5 this study # OS-95853 244 G. ruber 8830 50 9487 47.75 this study # 14761 280 G. ruber 10100 55 11106 72.5 Keigwin (2004) # 14762 290 G. ruber 10200 55 11193 62.5 Keigwin (2004) # #--------------------------------------- # Variables # Data variables follow that are preceded by "##" in columns one and two. # Variables list, one per line, shortname-tab-longname components (9 components: what, material, error, units, seasonality, archive, detail, method, C or N for Character or Numeric data) ## depth depth,sediment,,centimeter,,paleoceanography,,,N, ## age age,sediment,,calendar kiloyear before present,,paleoceanography,,,N, ## 231Pa 231Pa,sediment,,disintegration per minute per gram,,paleoceanography,,inductively-coupled plasma mass spectrometry,N,dpm/g is a standard unit used in sediment radiochemistry ## 231Pa_error 231Pa,sediment,two standard deviations,disintegration per minute per gram,,paleoceanography,,inductively-coupled plasma mass spectrometry,N,dpm/g is a standard unit used in sediment radiochemistry ## 230Th 230Th,sediment,,disintegration per minute per gram,,paleoceanography,,inductively-coupled plasma mass spectrometry,N,dpm/g is a standard unit used in sediment radiochemistry ## 230Th_error 230Th,sediment,two standard deviations,disintegration per minute per gram,,paleoceanography,,inductively-coupled plasma mass spectrometry,N,dpm/g is a standard unit used in sediment radiochemistry ## 238U 238U,sediment,,disintegration per minute per gram,,paleoceanography,,inductively-coupled plasma mass spectrometry,N,dpm/g is a standard unit used in sediment radiochemistry ## 238U_error 238U,sediment,two standard deviations,disintegration per minute per gram,,paleoceanography,,inductively-coupled plasma mass spectrometry,N,dpm/g is a standard unit used in sediment radiochemistry ## 232Th 232Th,sediment,,disintegration per minute per gram,,paleoceanography,,inductively-coupled plasma mass spectrometry,N,dpm/g is a standard unit used in sediment radiochemistry ## 232Th_error 232Th,sediment,two standard deviations,disintegration per minute per gram,,paleoceanography,,inductively-coupled plasma mass spectrometry,N,dpm/g is a standard unit used in sediment radiochemistry ## 238U/232Th 238U/232Th,sediment,,disintegration per minute per gram,,paleoceanography,,inductively-coupled plasma mass spectrometry,N,dpm/g is a standard unit used in sediment radiochemistry ## 238U/232Th_error 238U/232Th,sediment,two standard deviations,disintegration per minute per gram,,paleoceanography,,inductively-coupled plasma mass spectrometry,N,dpm/g is a standard unit used in sediment radiochemistry ## 231Pa_xs0_0.5 231Pa excess,sediment,,disintegration per minute per gram,,paleoceanography,,,N,Corrected for decay since deposition and for supported 231Pa activity using an assumed detrital 238U/232Th ratio of 0.5 ## 231Pa_xs0_0.7 231Pa excess,sediment,,disintegration per minute per gram,,paleoceanography,,,N,Corrected for decay since deposition and for supported 231Pa activity using an assumed detrital 238U/232Th ratio of 0.7 ## 230Th_xs0_0.5 230Th excess,sediment,,disintegration per minute per gram,,paleoceanography,,,N,Corrected for decay since deposition and for supported 230Th activity using an assumed detrital 238U/232Th ratio of 0.5 ## 230Th_xs0_0.7 230Th excess,sediment,,disintegration per minute per gram,,paleoceanography,,,N,Corrected for decay since deposition and for supported 230Th activity using an assumed detrital 238U/232Th ratio of 0.7 ## 231Paxs0/230Thxs0_0.5 231Pa/230Th excess,sediment,,dimensionless,,paleoceanography,,,N,Corrected for decay since deposition and for supported 231Pa and 230Th activity using an assumed detrital 238U/232Th ratio of 0.5 ## 231Paxs0/230Thxs0_0.7 231Pa/230Th excess,sediment,,dimensionless,,paleoceanography,,,N,Corrected for decay since deposition and for supported 231Pa and 230Th activity using an assumed detrital 238U/232Th ratio of 0.7 ## 231Paxs0/230Thxs_avg 231Pa/230Th excess,sediment,,dimensionless,,paleoceanography,,,N,Average value of 230Paxs0/230Thxs0 from two detrital 238U/232Th corrections (0.5 and 0.7) ## 231Paxs0/230Thxs0_avg_error 231Pa/230Th excess,sediment,one standard deviation,dimensionless,,paleoceanography,,,N,Average value of 230Paxs0/230Thxs0 from two detrital 238U/232Th corrections (0.5 and 0.7) ## 230Th_norm_mass_flux accumulation rate,sediment,,gram per square centimeter per kiloyear,,paleoceanography,,,N,Calculated from equations of Francois et al., 1990 and Francois et al., 2004 #------------------------ # Data: # Data lines follow (have no #) # Data line format - tab-delimited text, variable short name as header # Missing_Values: -999 depth age 231Pa 231Pa_error 230Th 230Th_error 238U 238U_error 232Th 232Th_error 238U/232Th 238U/232Th_error 0 0.09 0.171 0.002 2.707 0.042 2.052 0.012 1.184 0.006 1.733 0.013 231Pa_xs0_0.5 231Pa_xs0_0.7 230Th_xs0_0.5 230Th_xs0_0.7 231Paxs0/230Thxs0_0.5 231Paxs0/230Thxs0_0.7 231Paxs0/230Thxs_avg 231Paxs0/230Thxs0_avg_error 230Th_norm_mass_flux -999 -999 -999 -999 0 0.09 0.158 0.002 2.653 0.057 2.033 0.011 1.161 0.006 1.751 0.013 0.144 0.133 2.115 1.879 0.068 0.071 0.070 0.001 2.39 -999 -999 -999 -999 3 0.22 0.162 0.005 2.536 0.035 2.257 0.047 1.109 0.034 2.035 0.075 0.131 0.121 2.073 1.840 0.063 0.066 0.064 0.002 2.44 -999 -999 -999 -999 10 0.52 0.172 0.004 2.876 0.145 2.472 0.018 1.158 0.011 2.134 0.025 0.137 0.127 1.981 1.760 0.069 0.072 0.071 0.002 2.56 -999 -999 -999 -999 20 0.90 0.171 0.004 2.659 0.090 2.684 0.023 1.117 0.012 2.402 0.033 0.146 0.136 2.299 2.067 0.064 0.066 0.065 0.004 2.19 -999 -999 -999 -999 40 1.65 0.177 0.006 2.812 0.261 2.724 0.015 1.183 0.009 2.303 0.022 0.146 0.135 2.101 1.877 0.069 0.072 0.071 0.003 2.40 -999 -999 -999 -999 60 2.41 0.160 0.006 2.501 0.188 2.535 0.018 1.095 0.012 2.314 0.030 0.151 0.141 2.222 1.986 0.068 0.071 0.069 0.007 2.27 -999 -999 -999 -999 80 3.16 0.184 0.004 2.951 0.082 2.850 0.007 1.176 0.016 2.424 0.033 0.137 0.127 1.953 1.734 0.070 0.073 0.072 0.006 2.59 -999 -999 -999 -999 100 3.92 0.183 0.002 2.908 0.044 2.923 0.013 1.161 0.007 2.519 0.019 0.161 0.150 2.366 2.131 0.068 0.070 0.069 0.003 2.13 -999 -999 -999 -999 120 4.62 0.191 0.005 3.086 0.100 2.674 0.025 1.189 0.011 2.249 0.030 0.160 0.149 2.327 2.095 0.069 0.071 0.070 0.001 2.16 -999 -999 -999 -999 140 5.32 0.188 0.004 2.918 0.099 2.582 0.023 1.190 0.006 2.170 0.022 0.171 0.160 2.509 2.271 0.068 0.070 0.069 0.003 2.00 -999 -999 -999 -999 150 5.67 0.179 0.003 3.219 0.093 2.689 0.008 1.265 0.005 2.127 0.011 0.169 0.158 2.339 2.101 0.072 0.075 0.074 0.003 2.15 -999 -999 -999 -999 161 6.05 0.200 0.006 3.187 0.079 2.603 0.017 1.256 0.011 2.074 0.022 0.157 0.146 2.615 2.362 0.060 0.062 0.061 0.002 1.92 -999 -999 -999 -999 181 6.76 -999 -999 3.203 0.158 2.203 0.010 1.267 0.011 1.739 0.017 0.183 0.171 2.593 2.342 0.070 0.073 0.072 0.003 1.94 -999 -999 -999 -999 200 7.42 0.216 0.003 3.492 0.069 2.221 0.010 1.380 0.008 1.610 0.012 -999 -999 2.634 2.380 -999 -999 -999 -999 1.91 -999 -999 -999 -999 208 7.70 0.201 0.006 3.623 0.089 2.210 0.026 1.456 0.011 1.518 0.021 0.203 0.190 2.892 2.616 0.070 0.073 0.072 0.002 1.74 -999 -999 -999 -999 210 7.77 0.229 0.003 3.521 0.040 2.070 0.114 1.162 0.025 1.781 0.106 0.185 0.172 2.999 2.708 0.062 0.063 0.063 0.002 1.67 -999 -999 -999 -999 211 7.83 0.206 0.002 3.368 0.100 2.138 0.058 1.074 0.027 1.991 0.073 0.226 0.215 3.047 2.815 0.074 0.076 0.075 0.001 1.63 -999 -999 -999 -999 212 7.88 0.218 0.002 3.485 0.069 2.088 0.069 1.145 0.023 1.823 0.071 0.200 0.190 2.922 2.708 0.069 0.070 0.069 0.002 1.70 -999 -999 -999 -999 213 7.94 0.215 0.004 3.504 0.086 1.972 0.054 1.225 0.020 1.610 0.051 0.214 0.204 3.018 2.789 0.071 0.073 0.072 0.002 1.65 -999 -999 -999 -999 214 7.99 0.217 0.004 3.567 0.084 1.998 0.047 1.235 0.025 1.617 0.050 0.210 0.198 3.008 2.763 0.070 0.072 0.071 0.002 1.66 -999 -999 -999 -999 215 8.05 0.228 0.002 3.582 0.091 1.999 0.085 1.248 0.021 1.601 0.073 0.212 0.201 3.069 2.822 0.069 0.071 0.070 0.002 1.62 -999 -999 -999 -999 216 8.11 0.222 0.003 3.535 0.058 1.993 0.030 1.246 0.012 1.599 0.029 0.224 0.213 3.079 2.829 0.073 0.075 0.074 0.002 1.62 -999 -999 -999 -999 216 8.11 0.222 0.004 3.590 0.136 2.100 0.018 1.496 0.017 1.404 0.020 0.218 0.206 3.032 2.782 0.072 0.074 0.073 0.002 1.64 -999 -999 -999 -999 217 8.16 0.226 0.004 3.467 0.076 1.986 0.063 1.212 0.027 1.639 0.063 0.211 0.197 2.958 2.659 0.071 0.074 0.073 0.003 1.70 -999 -999 -999 -999 218 8.22 0.225 0.004 3.512 0.074 2.048 0.043 1.245 0.021 1.645 0.044 0.223 0.212 2.977 2.734 0.075 0.077 0.076 0.002 1.67 -999 -999 -999 -999 219 8.27 0.221 0.005 3.546 0.128 2.039 0.077 1.213 0.025 1.681 0.073 0.222 0.210 3.004 2.755 0.074 0.076 0.075 0.002 1.66 -999 -999 -999 -999 220 8.33 0.221 0.008 3.526 0.057 1.985 0.047 1.256 0.026 1.580 0.050 0.217 0.206 3.058 2.816 0.071 0.073 0.072 0.003 1.63 -999 -999 -999 -999 221 8.38 0.223 0.007 3.550 0.059 1.981 0.042 1.283 0.024 1.544 0.044 0.216 0.205 3.020 2.769 0.072 0.074 0.073 0.003 1.65 -999 -999 -999 -999 222 8.44 0.219 0.006 3.595 0.173 2.194 0.011 1.532 0.013 1.432 0.014 0.219 0.207 3.034 2.777 0.072 0.075 0.073 0.003 1.64 -999 -999 -999 -999 226 8.63 -999 -999 3.674 0.221 1.540 0.211 1.676 0.016 0.919 0.126 0.207 0.193 2.942 2.635 0.070 0.073 0.072 0.004 1.71 -999 -999 -999 -999 230 8.82 0.224 0.005 3.722 0.101 2.317 0.010 1.684 0.013 1.376 0.012 -999 -999 3.013 2.708 -999 -999 -999 -999 1.67 -999 -999 -999 -999 234 9.01 -999 -999 3.720 0.180 2.564 0.013 1.648 0.013 1.556 0.015 0.210 0.194 2.998 2.662 0.070 0.073 0.071 0.003 1.69 -999 -999 -999 -999 238 9.20 0.198 0.004 3.297 0.155 2.219 0.017 1.473 0.010 1.506 0.015 -999 -999 2.996 2.666 -999 -999 -999 -999 1.69 -999 -999 -999 -999 244 9.49 0.214 0.006 3.542 0.139 2.741 0.015 1.622 0.015 1.690 0.018 0.185 0.171 2.655 2.361 0.070 0.073 0.071 0.004 1.91 -999 -999 -999 -999 250 9.76 0.217 0.006 3.640 0.080 2.858 0.010 1.606 0.011 1.780 0.013 0.196 0.181 2.804 2.479 0.070 0.073 0.072 0.003 1.81 -999 -999 -999 -999 250 9.76 0.216 0.002 3.537 0.034 2.840 0.009 1.556 0.013 1.825 0.016 0.199 0.185 2.910 2.589 0.069 0.071 0.070 0.003 1.74 -999 -999 -999 -999 256 10.03 0.228 0.006 3.598 0.225 2.888 0.014 1.757 0.012 1.644 0.014 0.200 0.186 2.824 2.513 0.071 0.074 0.072 0.001 1.79 -999 -999 -999 -999 270 10.66 0.206 0.001 3.384 0.024 2.159 0.015 1.593 0.009 1.355 0.012 0.210 0.194 2.788 2.437 0.075 0.080 0.078 0.005 1.83 -999 -999 -999 -999 280 11.11 0.216 0.002 3.492 0.047 2.293 0.014 1.718 0.021 1.335 0.018 0.196 0.182 2.506 2.500 0.078 0.073 0.075 0.001 1.91 -999 -999 -999 -999 290 11.19 0.214 0.003 3.349 0.065 2.113 0.008 1.656 0.006 1.276 0.007 0.203 0.190 2.540 2.530 0.080 0.075 0.077 0.001 1.89 -999 -999 -999 -999 290 11.19 0.207 0.005 3.346 0.058 2.075 0.008 1.671 0.017 1.241 0.013 0.204 0.191 2.432 2.421 0.084 0.079 0.082 0.002 1.97 -999 -999 -999 -999