# Southwest Atlantic Deglacial Planktonic and Benthic D14C Data #----------------------------------------------------------------------- # World Data Center for Paleoclimatology, Boulder # and # NOAA Paleoclimatology Program #----------------------------------------------------------------------- # NOTE: Please cite Publication, and Online_Resource and date accessed when using these data. # If there is no publication information, please cite Investigators, Title, and Online_Resource and date accessed. # # # Online_Resource: http://ncdc.noaa.gov/paleo/study/17675 # # Original_Source_URL: ftp://ftp.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/sortor2011/sortor2011benth.txt # # Description/Documentation lines begin with # # Data lines have no # # # Archive: Paleoceanography #-------------------- # Contribution_Date # Date: 2015-01-05 #-------------------- # Title # Study_Name: Southwest Atlantic Deglacial Planktonic and Benthic D14C Data #-------------------- # Investigators # Investigators: Sortor, R.N.; Lund, D.C. #-------------------- # Description_and_Notes # Description: Planktonic and benthic foraminiferal D14C data from southwest Atlantic core KNR159-5-36GGC # for the deglacial period (~18-14 KYrBP). #-------------------- # Publication # Authors: Rachel N. Sortor and David C. Lund # Published_Date_or_Year: 2011-10-01 # Published_Title: No evidence for a deglacial intermediate water D14C anomaly in the SW Atlantic # Journal_Name: Earth and Planetary Science Letters # Volume: 310 # Edition: # Issue: 1-2 # Pages: 65-72 # DOI: 10.1016/j.epsl.2011.07.017 # Online_Resource: http://www.sciencedirect.com/science/article/pii/S0012821X1100433X # Full_Citation: # Abstract: The last deglaciation was characterized by an increase in atmospheric pCO2 and decrease in atmospheric radiocarbon activity. One hypothesis is that these changes were due to out-gassing of 14C-depleted carbon from the abyssal ocean. Reconstructions of foraminiferal D14C from the eastern tropical Pacific, Arabian Sea, and high latitude North Atlantic show that severe depletions in 14C occurred at intermediate water depths during the last deglaciation. It has been suggested that 14C-depleted water from the abyss upwelled in the Southern Ocean and was then carried by Antarctic Intermediate Water (AAIW) to these sites. However, locations in the South Pacific in the direct path of modern-day AAIW do not exhibit the D14C excursion and therefore cast doubt upon the AAIW mechanism (De Pol-Holz et al., 2010 and Rose et al., 2010). Here we evaluate whether or not a deglacial 14C anomaly occurred at intermediate depths in the Southwest Atlantic. We find that the deglacial benthic D14C trend at our site is similar to the atmospheric D14C trend. Our results are also largely consistent with results from U/Th-dated corals at shallower water depths on the Brazil Margin (Mangini et al., 2010). We find no evidence in the southwestern Atlantic of a ~300 per mil decrease in intermediate water D14C from 18 to 14 kyr BP like that observed in the eastern tropical Pacific (Marchitto et al., 2007). When our results are paired with those from the South Pacific, it appears AAIW did not carry a highly 14C-depleted signal during the deglaciation. Another source of carbon is apparently required to explain the intermediate-depth D14C anomalies in the North Atlantic, Indian, and Pacific Oceans. #------------------ # Funding_Agency # Funding_Agency_Name: # Grant: #------------------ # Site_Information # Site_Name: KNR159-5-36GGC # Location: Ocean>Atlantic Ocean>South Atlantic Ocean # Country: # Northernmost_Latitude: -27.5167 # Southernmost_Latitude: -27.5167 # Easternmost_Longitude: -46.4667 # Westernmost_Longitude: -46.4667 # Elevation: -1268 m #------------------ # Data_Collection # Collection_Name: Sortor2011benth # Earliest_Year: 20110 # Most_Recent_Year: 4730 # Time_Unit: Cal. Year BP # Core_Length: m # Notes: #------------------ # Chronology: # # The age model for KNR159-5-36GGC was developed using planktonic 14C ages calibrated with CALIB 6.0 (Reimer et al., 2009). # # #---------------- # Variables # # Data variables follow that are preceded by "##" in columns one and two. # Data line variables format: Variables list, one per line, shortname-tab-longname-tab-longname components (9 components: what, material, error, units, seasonality, archive, detail, method, C or N for Character or Numeric data) # ##UCIAMS UCIAMS sample number,,,,,,,,N ##depth_cm depth, , , cm, , , , ,N ##Genera Genera,,,,,,,,C ##age_14cBP 14C age, , , years before present, , , , ,N ##age_14cBPerr 14C age error, , , years, , , , ,N ##mod_frac Modern Fraction, , , , , , , ,N ##mod_frac_err Modern Fraction Error, , , , , , , ,N ##age_calBP Age, , , calendar years before present, , , , ,N ##age_calBPerr Age error, , , calendar years before present, , , , ,N ##Delta14C Delta 14C, , , per mil, , , , ,N ##notes ,,,,,,,,C # #---------------- # Data: # Data lines follow (have no #) # Data line format - tab-delimited text, variable short name as header # Missing Values: # Benthic radiocarbon results KNR159-5-36GGC UCIAMS depth_cm Genera age_14cBP age_14cBPerr mod_frac mod_frac_err age_calBP age_calBPerr Delta14C notes 73527 30.5 Cibicidoides and Uvigerina 4730 40 0.5550 0.0027 -190 43 - negative B-P age 73528 40.5 Cibicidoides and Uvigerina 7325 25 0.4017 0.0011 938 31 -76.1 73529 50.5 Cibicidoides and Uvigerina 8150 30 0.3625 0.0013 325 34 -13.3 94727 57.5 Cibicidoides and Uvigerina 9745 40 0.2974 0.0014 1300 45 -112.3 73530 60.5 Cibicidoides and Uvigerina 10160 45 0.2823 0.0014 1045 49 -67.8 94728 65.5 Cibicidoides and Uvigerina 10420 40 0.2733 0.0012 995 45 -52.2 77911 67.5 Cibicidoides and Uvigerina 11480 70 0.2394 0.0019 1055 74 -31.5 73531 70.5 Cibicidoides and Uvigerina 11590 70 0.2364 0.0020 885 76 16.0 73532 80.5 Cibicidoides and Uvigerina 12385 40 0.2140 0.0010 900 50 23.3 77912 85.5 Cibicidoides and Uvigerina 13340 30 0.1900 0.0007 880 42 22.1 73533 90.5 Cibicidoides and Uvigerina 12610 260 0.2080 0.0066 -95 262 - negative B-P age 77913 95.5 Cibicidoides and Uvigerina 13670 35 0.1824 0.0007 1395 46 -45.1 73534 100.5 Cibicidoides and Uvigerina 13885 50 0.1775 0.0011 1175 58 1.7 77914 105.5 Cibicidoides and Uvigerina 13915 35 0.1769 0.0007 620 49 153.1 73535 110.5 Cibicidoides 14390 45 0.1668 0.0009 925 57 119.4 73536 110.5 Uvigerina 14255 45 0.1696 0.0009 790 57 138.1 77915 115.5 Cibicidoides and Uvigerina 14360 30 0.1674 0.0006 730 42 176.4 73537 120.5 Cibicidoides 14710 45 0.1602 0.0009 1360 60 58.0 73538 120.5 Uvigerina 14640 45 0.1617 0.0008 1290 60 67.7 77916 125.5 Cibicidoides and Uvigerina 14900 35 0.1564 0.0006 1135 49 131.4 73539 130.5 Cibicidoides 15080 40 0.1530 0.0007 1125 53 145.5 73540 130.5 Uvigerina 15100 60 0.1526 0.0010 1145 69 142.1 94729 134.5 Cibicidoides and Uvigerina 15710 90 0.1415 0.0014 1370 114 108.7 77917 142.5 Cibicidoides and Uvigerina 14195 30 0.1709 0.0006 2220 39 - reversal 94730 146.5 Cibicidoides and Uvigerina 15890 90 0.1384 0.0014 650 127 245.8 73541 150.5 Cibicidoides 16390 55 0.1300 0.0008 890 89 190.9 73542 150.5 Uvigerina 16080 290 0.1352 0.0048 580 298 238.1 large error 77918 180.5 Cibicidoides and Uvigerina 18000 40 0.1064 0.0005 490 72 207.9 94732 182.5 Cibicidoides and Uvigerina 18380 100 0.1014 0.0012 790 128 217.7 77919 185.5 Cibicidoides and Uvigerina 19320 60 0.0902 0.0006 540 92 274.4 77920 190.5 Cibicidoides and Uvigerina 20110 60 0.0818 0.0006 770 85 261.7 77921 200.5 Cibicidoides and Uvigerina 16810 60 0.1233 0.0008 1285 78 - reversal