Annual resolution grain analysis, the ELSA-Dust-Stack

  • Figure Dust Grains
  • Graphic (1) Eolian Dust
  • Graphic (2) Eolian Dust

10 cm segments of the sediment are taken from the core and impregnated with a resin to harden the sediment. The resin impregnated blocks are cut and grinded to 30 µm thickness of a petrographic thin section. Quartz particles are detected under a scanning microscope and the grain size of quartz determined by the RADIUS software developed by Klemens Seelos (Seelos & Sirocko, 2007). The scanned thin section is analyzed in 1 mm increments to determine the grain size distribution of the quartz fraction with mm resolution. Sorting parameters are then used to quantify the eolian quartz fraction (Seelos et al., 2009). Scanning has been done for thin sections from the core OW1 from Oberwinkler Maar. The resultant time series was named the ELSA-Dust-Stack-2009, which revealed increased dust proportions during all MIS 3 stadials and the LGM. Dust, however, was absent from the interstadial sections.

First results on µXRF geochemical analysis were presented by Dietrich & Seelos (2010) to reconstruct wind directions during the LGM. The presence of Ca-rich eolian grains was used by these authors to determine the glacial dust fraction transported by winds from the East. This approach worked only for the sediments from Dehner Maar, because this maar is westward from the Eifel carbonate rock regions. Fuhrmann et al. (2021) adapted this approach for the carbonate rock fraction deposited in Auel.