Marine Isotope Stage 5e diatom assemblages in marine sediment core ANTA91-8 (-70.78 degN, 172.83 degE, Cruise ANTA91) - VERSION 2

• Main Authors: Chadwick, Matthew, Allen, Claire
• Format: Dataset
• Language: English
• Published: NERC EDS UK Polar Data Centre 2021
• Subjects: "EARTH SCIENCE","BIOLOGICAL CLASSIFICATION","PLANTS","MICROALGAE","DIATOMS"; "EARTH SCIENCE","SOLID EARTH","GEOCHEMISTRY"; Diatoms; Interglacial; Sediment core; Southern Ocean; Olympus
• Online Access: https://dx.doi.org/10.5285/bda782a6-e89a-41a6-8791-f28001bc5d11; https://data.bas.ac.uk/full-record.php?id=GB/NERC/BAS/PDC/01512

This dataset presents the relative diatom abundances of 56 species/groups from the 132-120 ka interval in marine sediment core ANTA91-8 (-70.78 degN, 172.83 degE). This age interval corresponds to the peak of Marine Isotope Stage 5e. 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. The age model for this dataset has been updated, with new tiepoints between the sediment core magnetic susceptibility and the LR04 benthic delta-O-18 stack selected to improve the graphical alignment. This project was funded by the UK Natural Environment Research Council Grant NE/L002531/1. : Sediment core material was collected on Cruise ANTA91 (1990-1991) of the R/V Cariboo (http://www.mna.it/ts-samples/anta91-8c). For the diatom assemblage data, microscope slides were produced using a method adapted from Scherer (1994). Samples of 8-22 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 Aligned to the LR04 chronology by correlating the sediment core magnetic susceptibility to the LR04 benthic foraminiferadelta-O-18 stack (Lisiecki & Raymo 2005). Translation between the LR04 and EDC3 chronologies uses the conversion table in Parrenin et al. (2013). This data set is the updated version of the following dataset: https://doi.org/10/fqj8 : Instrumentation used: Gravity 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 0.7-2 cm and age resolution of 0.3-0.8 ka.