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Stable isotope and trace element data for planktonic foraminifera from IODP Site U1338 (NERC Grant NE/I528750/1)
Oxygen and carbon isotope ratios (δ18O, δ13C) were measured on 10 to 12 shells of mixed-layer dwelling species Globigerinoides subquadratus from the 250 to 315 μm size fraction from 425 meters composite depth (mcd) until its extinction at 390 mcd. Analyses then continue with Globigerinoides spp. until 350 mcd. In a few samples, where foraminiferal density was low, only 5–7 specimens were analyzed. Analyses were made with a VG Optima mass spectrometer with multi prep device at the British Geological Survey, Keyworth, UK. When picking shells, care was taken to exclude individuals with broken or missing chambers, although preservation of specimens was generally excellent (Fox & Wade, 2013). The external reproducibility of our measurements is ±0.07‰ and ±0.05‰ for δ18O and δ13C respectively. To examine the reproducibility of the results, duplicate measurements were made on 35 samples (5%), which indicate mean reproducibility better than ±0.12‰ and ±0.14‰ for δ18O and δ13C, respectively. Oxygen isotope data are reported as per mil on the VPDB scale (Table S1) calibrated through laboratory and international standards. At ODP Site 1146, δ18O and δ13C were measured by Holbourn et al., (2010) on the mixed-layer dwelling planktonic foraminifera Globigerinoides obliquus or Gs. subquadratus, using 10 to 20 well-preserved tests from the size fraction 250-350 μm. Paired measurements in 51 samples indicate no significant offset in δ18O and δ13C between Gs. obliquus and Gs. subquadratus. Detailed methods are outlined in Holbourn et al., (2010). δ13C data are not used here. For Mg/Ca analyses, we selected 25–35 specimens of Trilobatus quadrilobatus (140–550 μg) from the 250 to 315 μm size fraction; the same size fraction as used for δ18O analysis, to minimize size-related intraspecific elemental variation (Elderfield et al., 2002). Analyses were performed on 86 samples over the studied interval. The tests were gently crushed and subsequently cleaned according to the protocol of Martin & Lea (2002) to remove clays. Cleaning included a reductive step with hydrazine to remove Mn-(hydr)oxides. Samples were measured on an ICP-AES device at Christian-Albrechts-Universität zu Kiel, Germany. Analytical precision is ~1.1%, based on measurements of an internal laboratory standard. Replicate Mg/Ca measurements revealed an average standard deviation of ~0.08 mmol/mol. Adequate cleaning is indicated by very low Fe/Ca, Al/Ca and Mn/Ca ratios.
Trace metal concentrations and lipid biomarkers used in the interpretation of a sediment record (IODP U1419) from the Gulf of Alaska (NERC Grant NE/N011112/1)
"Three spreadsheet tables of biomarker data, element ratios, and accumulation rates. Sediment samples from IODP Expedition 341, Site U1419 in the Gulf of Alaska. Site U1419 is located in 721 m water depth on the continental slope above the Khitrov basin. Extracted lipids were analysed by HPLC-MS. Two independent methods for bulk element geochemistry analyses were applied to the samples. More details available in the paper Zindorf et al., 2020 https://doi.org/10.1016/j.chemgeo.2020.119864"
IODP Exp. 353 Site U1446 Indian Summer Monsoon proxies across Termination II (NERC grant NE/L002493/1)
Data collected from IODP Expedition 353, Site U1446. Data represent ISM derived rainfall and runoff proxies across Termination II. Mid-depth on CCSFA scale. Two age columns derived from age models based on LR04 benthic oxygen isotope record and AICC2012 chronology. Sheet 2 include Globigerinoides ruber sensu-stricto oxygen isotope data, Mg/Ca, Mn/Ca, U/Ca and Nd/Ca Sheet 3 include discrete portable X-Ray Fluorescence data for Ti, Al, K and Rb.
Dissolved rhenium and other dissolved ions in Alpine catchments of the Erlenbach and Vogelbach (Switzerland) and the East River (Colorado, USA) (NERC Grant NE/I001719/1)
The measurements and data contained here were obtained to study the chemical weathering of sedimentary rocks, and more specifically the oxidation of rock organic carbon and the associated release of CO2. The primary aim was to better understand the production and mobility of the trace element rhenium during weathering, because this element has been proposed as a proxy for rock organic carbon oxidation. The study focused on three Alpine catchments that drain sedimentary rocks, which all experience moderate to high erosion rates where oxidative weathering rates are thought to operate faster. Two catchments were located in Switzerland - the Erlenbach and Vogelbach, and one catchment in Colorado, USA - the East River. To study chemical weathering and the production and mobility of rhenium, a suite of samples were collected to capture the source and products of weathering reactions. These focused on stream and river water, river sediments and weathering profiles collected on sedimentary rocks. The Swiss catchments, water samples were collected from 2011 and 2012 to capture changes in river flow and seasonal changes in hydro-climate. Samples were collected from a gauging station operated by the Swiss Federal Institute for Forest, Snow and Landscape Research - WSL. In the East River, samples were collected from the gauging station operated by the Lawrence Berkeley National Laboratory Watershed Function Scientific Focus Area from 2015 and 2016. Additional samples included snow samples collected from the Erlenbach. All water samples were analysed for their major dissolved ion content by Ion Chromatography. Dissolved rhenium concentrations were determined by High Resolution and Quadrupole Inductively Coupled Plasma Mass Spectrometry. Solid samples were digested and analysed for Re content by ICP-MS. These geochemical measurements were paired with water discharge data to quantify the flux of dissolved elements, using rating curves and flux-weighted average methods, and interpret the hydrological context of ion production and mobility through the landscape. This new data acquisition was funded by a European Research Council Starting Grant to Robert Hilton (ROC-CO2 project, grant 678779) and a Natural Environment Research Council (NERC), UK, Standard Grant (NE/I001719/1). Further details of subsequent data analysis and interpretation can be found in Hilton, R.G., et al., 2021, Concentration-discharge relationships of dissolved rhenium in Alpine catchments reveal its use as a tracer of oxidative weathering, Water Resources Research