The Avaatech XRF Core Scanner: technical description and applications to NE Atlantic sediments

Abstract

X-ray fluorescence (XRF) core scanning provides rapid high-resolution (down to 1 mm) records of chemical composition on split sediment cores. The measurements are non-destructive and require very limited sample preparation. The new Avaatech XRF Core Scanner, operational since 2002, covers the atomic mass range from Al to U. Instrument parameters, especially tube voltage, can be adjusted to provide optimum settings for selected elements or sets thereof. Owing to the nature of the surface of split sediment cores, particularly effects resulting from sample inhomogeneity and surface roughness, results are semiquantitative, yet provide reliable records of the relative variability in elemental composition downcore. Selected case studies from diverse sedimentary settings in the NE Atlantic Ocean illustrate a range of applications of XRF logging data. These include preliminary stratigraphic interpretations (glacial-interglacial cycles), provenance studies of the terrigenous sediment fraction, lithological characterization, early diagenetic processes and distinction between carbonate phases (aragonite v. calcite).

Late Oligocene obliquity-paced contourite sedimentation in the Wilkes Land margin of East Antarctica: implications for paleoceanographic and ice sheet configurations

“…feldspars and clays) and biogenic carbonates (e.g. Richter et al, 2006, Foubert and Henriet, 2009, Rothwell and Croudace, 2015. Based on these observations, we interpret that Ca in our sediments is mainly of biogenic origin (CaCO 3 ).…”

“…This non-destructive method yields element intensities on the surface of split sediment cores and provides statistically significant data for major and minor elements (Richter et al, 2006;O'Regan et al 2010, Wilhelms-Dick et al, 2012. Detailed bulk-chemical composition records acquired by XRF core scanning allows accurate determination of sedimentological changes as well as assessment of the contribution of the various components in the biogenic and lithogenic fraction of the marine sediments 230 (Croudace et al, 2006).…”

The meridional temperature gradient in the eastern North Atlantic during MIS 11 and its link to the ocean–atmosphere system

“…The here reported data have been acquired by XRF Core Scanner I at MARUM using a KEVEX Psi Peltier Cooled Silicon Detector and a KEVEX X-ray Tube 52500008-02 with the target material molybdenum (Mo). The detection limit for iron for the XRF scanner used is 210 ppm (Richter et al 2006). Repeatability tests at the surface of split sediment core halves have shown that the error is smaller than 1% if the core surface is of high quality (Röhl and Abrams, 2000), which was the case for the scanned core sections of this study.…”

Plio-Pleistocene trends in ice rafted debris on the Lomonosov Ridge

“…1). The XRF core-scanning measurements of the ACEX cores were obtained directly at the split core surface of the archive half for the upper 20 m of the composite section using the XRF core scanner I at the University of Bremen (Rö hl and Abrams, 2000), which is an updated version of the CORTEX scanner (Richter et al, 2006). The XRF scanner measurements were carried out with a KEVEX Ó X-ray tube, a Mo detector, a generator setting of 20 kV and a sampling time of 30 s to obtain the element intensities from K through to Sr.…”