Benthic Foraminifera trace elements to calcium ratios and bottom water temperatures from the last 27,000 years of sediment core GeoB9512-5
This dataset contains element to calcium ratios (Mg/Ca, Sr/Ca, Mn/Ca, Fe/Ca, Ba/Ca and Al/Ca in mmol/mol) obtained from gravity core GeoB9512-5 (Mulitza et al., 2005). Data is presented for 144 samples Uvigerina mediterranea (87 samples), Uvigerina peregrina (1 sample), Melonis barleeanus (40 samples) and Globobulima turgida (16 samples). 8 duplicate samples (indicated in column "Duplicates"). Some other duplicate samples were picked to represent different test sizes (comment on size in column "Comments") and were picked and crushed separately. The microfossil material came from fresh mud, washed through a 63 µm sieve using deionized water, dried at 45°C for less than 24 hours, and dry sieved. The benthic foraminifera used, were retrieved from the fraction >150 µm. Between 1 and 9 tests of U. mediterranea, 3 and 12 specimens for M. barleeanus and between 4 and 12 individuals of Globobulimina were used for analyses. Before analysis, foraminifera samples were crushed and cleaned with water, methanol and hot buffered hydrogen peroxide with no reductive cleaning step (Johnstone et al., 2016). Samples were measured using an Inductively Coupled Plasma Optical Emission Spectrometer (ICP-OES)—Agilent Technologies 700 Series with Cetac ASX-520 autosampler at the following spectral lines: Ca (315.9 nm), Mg (279.6 nm), Sr (421.6), Fe (238.2 nm), and Mn (257.6 nm), Ba (455.4 nm) and Al (167.0 nm) calibrated using linear regressions. Calibration standards consisted of a blank and five multi-element standards of between 20 and 100 ppm Ca. Instrumental precision was monitored by using a commercial multi-element standard solution (SCP, France), and commercial powder sample ECRM752-1. Theoretical value (measured value, σ standard deviation, standard error) in mmol/mol for the SCP standard during these runs were: Mg/Ca, 2.955 (2.959, 0.030, 0.0029), Sr/Ca, 1.402 (1.402, 0. 016, 0.0015), Mn/Ca 0.3234 (0.3291, σ 0.0019, 0.00019), Fe/Ca, 0.3312 (0.3228, σ 0.0034, 0.00033), Ba/Ca, 0.00832 (0.00840, σ 0.00034, 0.000033) and Al/Ca 0.678 (0.695, σ 0.018, 0.0018), n=108. Mg/Ca of dissolved, centrifuged, ECRM 752-1 (measured at 3.750 σ 0.015, 0.0014 by Greaves et al. (2005)) was 3.735 σ 0.031, 0.0057. The median ages for the samples reported here were estimated with the Bacon script (Blaauw and Christen, 2011) in RStudio and the calibration curve Marine20 (Heaton et al., 2020), with published radiocarbon ages from the same site (Barragán-Montilla and Mulitza, in review). Bottom water temperatures (BWT) were estimated using the calibrations by: (1) Elderfield et al. (2010) (Mg/Ca= 0.81 + 0.074BWT) and Roberts et al. (2016) (Mg/Ca=0.843 + 0.0915T) for Uvigerina species Mg/Ca and (2) Kristjánsdóttir et al. (2007) (Mg/Ca=0.658 * exp [0.137BWT]) for Melonis barleeanus Mg/Ca, and (3) Weldeab et al. (2016) (Mg/Ca= 2.22 + 0.36BWT) for Globobulimina sp.
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