# Chronostratigraphy and stable isotopes of Site U1385 (Shackleton site) on the Iberian Margin over the past 1.5 Ma #----------------------------------------------------------------------- # World Data Center for Paleoclimatology, Boulder # and # NOAA Paleoclimatology Program #----------------------------------------------------------------------- # 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/19782 # Online_Resource: http://www1.ncdc.noaa.gov/pub/data/paleo/paleocean/by_contributor/hodell2015/hodell2015-u1385-med.txt # # Archive: Paleoceanography # # Parameter_Keywords: age control, oxygen isotopes, carbon isotopes #--------------------------------------- # Contribution_Date # Date: 2016-02-11 #--------------------------------------- # Title # Study_Name: Chronostratigraphy and stable isotopes of Site U1385 (Shackleton site) on the Iberian Margin over the past 1.5 Ma #--------------------------------------- # Investigators # Investigators: Hodell, David #--------------------------------------- # Description_Notes_and_Keywords # Description: Carbon isotope data to be added when published. #--------------------------------------- # Publication # Authors: Hodell, D., L. Lourens, S. Crowhurst, T. Konijnendijk, R. Tjallingii, F. Jiménez-Espejo, L. Skinner, P.C. Tzedakis, and Shackleton Site Project Members # Published_Date_or_Year: 2015 # Published_Title: A reference time scale for Site U1385 (Shackleton Site) on the SW Iberian Margin # Journal_Name: Global and Planetary Change # Volume: 133 # Issue: # Pages: 49-64 # Report Number: # DOI: 10.1016/j.gloplacha.2015.07.002 # Full_Citation: # Abstract: We produced a composite depth scale and chronology for Site U1385 on the SW Iberian Margin. Using log(Ca/Ti) measured by core scanning XRF at 1-cm resolution in all holes, a composite section was constructed to 166.5 meter composite depth (mcd) that corrects for stretching and squeezing in each core. Oxygen isotopes of benthic foraminifera were correlated to a stacked d18O reference signal (LR04) to produce an oxygen isotope stratigraphy and age model. Variations in sediment color contain very strong precession signals at Site U1385, and the amplitude modulation of these cycles provides a powerful tool for developing an orbitally-tuned age model. We tuned the U1385 record by correlating peaks in L* to the local summer insolation maxima at 37°N. The benthic d18O record of Site U1385, when placed on the tuned age model, generally agrees with other time scales within their respective chronologic uncertainties. The age model is transferred to down-core data to produce a continuous time series of log(Ca/Ti) that reflect relative changes of biogenic carbonate and detrital sediment. Biogenic carbonate increases during interglacial and interstadial climate states and decreases during glacial and stadial periods. Much of the variance in the log(Ca/Ti) is explained by a linear combination of orbital frequencies (precession, tilt and eccentricity), whereas the residual signal reflects suborbital climate variability. The strong correlation between suborbital log(Ca/Ti) variability and Greenland temperature over the last glacial cycle at Site U1385 suggests that this signal can be used as a proxy for millennial-scale climate variability over the past 1.5 Ma. Millennial climate variability, as expressed by log(Ca/Ti) at Site U1385, was a persistent feature of glacial climates over the past 1.5 Ma, including glacial periods of the early Pleistocene (‘41-kyr world’) when boundary conditions differed significantly from those of the late Pleistocene (‘100-kyr world’). Suborbital variability was suppressed during interglacial stages and enhanced during glacial periods, especially when benthic d18O surpassed ~ 3.3–3.5‰. Each glacial inception was marked by appearance of strong millennial variability and each deglaciation was preceded by a terminal stadial event. Suborbital variability may be a symptomatic feature of glacial climate or, alternatively, may play a more active role in the inception and/or termination of glacial cycles. #--------------------------------------- # Funding_Agency # Funding_Agency_Name: NERC # Grant: NE/K005804/1 #--------------------------------------- # Site Information # Site_Name: IODP Site U1385 # Location: Northern Atlantic Ocean # Country: Iberian Margin # Northernmost_Latitude: 37.5714667 # Southernmost_Latitude: 37.5714667 # Easternmost_Longitude: -10.12603333 # Westernmost_Longitude: -10.12603333 # Elevation: -2578 #--------------------------------------- # Data_Collection # Collection_Name: IODP U1385 Mediterranean age Hodell15 # First_Year: 1399600 # Last_Year: 0 # Time_Unit: cal yr BP # Core_Length: # Notes: #--------------------------------------- # Chronology_Information # Chronology: #--------------------------------------- # 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_rmcd depth,,,m,,,revised composite,,N ## age-med age,,,calendar ka BP,,,,based on the previously published Mediteranean-tuned age model of Hodell et al. 2015,N ## sedrate sedimentation rate,,,cm/kyr,,Paleoceanography,,,N #------------------------ # Data # Data lines follow (have no #) # Data line format - tab-delimited text, variable short name as header # Missing Value: NA depth_rmcd age-med sedrate 0.00 0.00 NA 1.34 9.32 14.40 4.34 24.73 19.48 15.86 79.24 21.12 18.66 106.56 10.27 19.52 116.28 8.87 21.78 128.94 17.79 23.75 152.64 8.33 25.23 165.34 11.66 26.11 178.42 6.72 26.65 185.79 7.35 28.83 195.89 21.61 31.11 212.32 13.86 33.37 240.06 8.16 40.65 289.16 14.82 44.14 310.58 16.28 46.63 331.94 11.65 55.60 409.99 11.49 55.79 432.65 0.85 59.85 485.03 7.75 62.64 503.79 14.89 66.07 525.05 16.11 66.66 527.98 20.34 72.94 575.92 13.09 74.14 600.33 4.94 76.42 617.26 13.46 77.83 645.64 4.96 79.31 668.81 6.40 81.30 688.63 10.00 83.29 711.86 8.59 86.28 732.38 14.58 91.45 785.72 9.68 93.25 804.93 9.38 95.39 821.20 13.15 97.78 846.46 9.47 99.25 864.29 8.24 101.62 883.32 12.45 103.67 902.07 10.93 107.16 936.80 10.05 109.49 958.81 10.59 111.02 977.25 8.29 113.08 996.82 10.53 116.34 1023.08 12.42 116.84 1026.88 12.98 119.84 1050.99 12.47 122.06 1072.20 10.47 124.06 1093.43 9.41 126.90 1116.09 12.56 132.19 1166.75 10.43 134.60 1185.99 12.51 136.97 1201.76 15.04 140.52 1245.07 8.21 142.08 1262.72 8.80 144.71 1279.90 15.36 145.98 1297.02 7.40 148.69 1316.79 13.68 152.00 1336.86 16.52 154.78 1357.15 13.72 157.45 1378.01 12.78 160.87 1399.60 15.84