Publication Date:
2023-05-12
Description:
The Benguela Upwelling System is situated between 18°S and 26°S and is characterized by seasonally variable upwelling cells, elevated surface primary and secondary productivity, high sedimentary organic carbon concentrations (up to 20 %), and locally stable bottom water anoxia. Between 2014 and 2019, surface sediment cores were collected, subsampled, and analysed using geochemical and sedimentological tools. For the grain size fractionation, a combined sieve-centrifuge-filtering approach was developed to create seven fractions (〉 250, 250-200, 200-125, 125-63, 63-10, 10-2, ≤ 2.0 µm) and the density fractionation followed a centrifugation sequence to yield four fractions using sodium polytungstate (NaW) heavy liquid (≤ 1.6, 1.6-2.0, 2.0-2.5, 〉 2.5 g cm-3) (cf., Wakeham et al., 2009, https://doi.org/10.1016/j.marchem.2009.08.005). The bulk surface sediment and each fraction were analysed for TOC (%), radiocarbon age (F14C), and surface area (m2 g-1). Together with literature data, these samples are used to test and illustrate a novel hypothesis on sediment hydrodynamic properties in oxygen-depleted environments.
Keywords:
Benguela Upwelling System; density fractionation; grain size analysis; radiocarbon isotope (Fm); SLOB; Total Organic Carbon
Type:
Dataset
Format:
application/zip, 16 datasets
