Sequential extraction procedure to obtain the composition of terrigenous detritus in marine sediments

MethodsX. 2020 Apr 20:7:100888. doi: 10.1016/j.mex.2020.100888. eCollection 2020.

Abstract

The geochemical and isotopic composition of terrigenous clays from marine sediments can provide important information on the sources and pathways of sediments. In order to extract the detrital signal from bulk marine sediments, standard sediment leaching methods are commonly applied to remove carbonate and ferromanganese oxides. In comparison to most previous studies that aimed to extract the terrestrial signal from marine sediments we additionally applied a CsCl wash throughout the sample preparation Simon et al. [1]. The motivation behind that extra step, not frequently applied, is to remove ions that are gained on the clay surface due to re-adsorption of authigenic trace metals in the ocean or during the leaching procedure and thus could alter the original composition of the detrital fraction if no cation exchange was applied. Here we present an improved and detailed step-by-step leaching protocol for the extraction of the detrital fraction of bulk deep-sea sediments including commonly used buffered acetic acid and acid-reductive mix solutions including a final cation exchange wash.•standard method to remove carbonate and ferromanganese oxides and Stokes settling to isolate the clay fractions•additional application of cation cation exchange wash (CsCl)•removal of ions that are gained on the clay surface due to adsorption of authigenic trace metals in the ocean or during the leaching procedure.

Keywords: Cation exchange wash; Composition of detrital fraction; Sediment leaching protocol.