Marine Isotope Stage 5e diatom assemblages in marine sediment core U1361A (-64.41 degN, 143.89 degE, IODP Exp. 318)

• Main Authors: Chadwick, Matthew, Allen, Claire
• Format: Dataset
• Language: English
• Published: UK Polar Data Centre, Natural Environment Research Council, UK Research & Innovation 2021
• Subjects: "EARTH SCIENCE","BIOLOGICAL CLASSIFICATION","PROTISTS","DIATOMS"; Diatoms; Interglacial; Sediment core; Southern Ocean; Olympus
• Online Access: https://dx.doi.org/10.5285/fe815073-28ee-462d-bee3-09e0da2f3866; https://data.bas.ac.uk/full-record.php?id=GB/NERC/BAS/PDC/01453

This dataset presents the relative diatom abundances of 56 species/groups from the 132-120 ka interval in marine sediment core U1361A (-64.41 oN, 143.89 oE). This age interval corresponds to the peak of Marine Isotope Stage 5e (130- 116 ka). Microscope slides were prepared using a method adapted from Scherer (1994) and 300+ diatom valves were counted for each depth sample to produce the relative percentage abundance of each diatom species/group. This project was funded by the UK Natural Environment Research Council Grant NE/L002531/1 : Sediment core material was collected on IODP Exp. 318 (2010) of the R/V JOIDES Resolution (https://doi.org/10.2204/iodp.proc.318.101.2011). For the diatom assemblage data, microscope slides were produced using a method adapted from Scherer (1994). Samples of 7-20 mg were exposed to 10% Hydrochloric acid to remove any carbonate, 30% Hydrogen peroxide to break down organic material and a 4% Sodium Hexametaphosphate solution to promote disaggregation and placed in warm water bath for minimum 12 hours. The material was homogenised into a ~10cm water column and allowed to settle randomly onto coverslips over a minimum of 4 hours. The water was drained away and coverslips were mounted on microscope slides with Norland Optical Adhesive (NOA 61). Slides were investigated with a light microscope (Olympus BH-2 at x1000 magnification) and a minimum of 300 diatom valves were counted for each sample. Age Model Wilson et al. (2018) align core U1361A to the LR04 chronology by correlating the sedimentology to glacial/interglacial periods alongside biostratigraphic markers. Translation between the LR04 and EDC3 chronologies uses the conversion tables in Parrenin et al. (2013). : Instrumentation: Piston corer, Diatom settling tanks and bench, Olympus BH-2 light microscope. : All diatom abundance values have an error of ±0.16 %. Ages for samples have a chronological uncertainty of ~2 ka. Sediment samples have a depth resolution of 2-5 cm and age resolution of 1.5-3 ka.