Great areas in the Carpathian Basin are covered by Quaternary eolian deposits, providing
excellent archives for paleoclimatic and paleoenvironmental studies.
Detailed grain-size investigation of five loess-paleosol sequences (Süttő, Basaharc,
Hévízgyörk, Villánykövesd, Beremend; Hungary) were carried out with sampling resolution
of 2 cm. Time frame for the investigations were elaborated by luminescence (post-IR
IRSL) and Amino Acid Racemization (AAR) dating.
The samples were only treated by 1% ammonium hydroxid, therefore they can be considered
bulk samples. Test measurements were also carried out on samples which were also treated
by HCl or H2SiF6 in order to dissolve carbonates, or any other minerals but quartz,
respectively. Grain-size distributions were determined using a Beckman-Coulter LS
13320 PIDS laser diffraction particle size analyzer, covering the range of 0.02-2000
μm, at the Leibniz Institute for Applied Geophysics (LIAG), in Hannover.
Clay- and sand content and U-ratio were calculated from the grain-size distribution
of each sample and these values were plotted against the depth of the profiles. Comparing
the variation of these values and trends, temporal and spatial changes could be concluded.
Most of the individual grain size distribution curves were polimodal, therefore numerical
partitioning using Weibull distribution can be applied to separate finer and coarser
components of the curves. Changes in the relative proportions of these components
throughout all sequences can be interpreted as temporal and spatial changes of the
different transport mechanism. Limitations, practicability of the method, as well
as results and their interpretation will be presented in this study.
Thanks to the Leibniz Institute for Applied Geophysics, Hannover for the grain size
measurements and to the Hungarian NRDIO projects K119366 and 100315. This study was
also funded by the ÚNKP-17-4 and ÚNKP-18-4 New National Excellence Program of the
Ministry of Human Capacities.