LOESSFEST'09 | Aug. 31st – Sept. 3rd, 2009 |Novi Sad-Serbia
Highly Resolved Color Indices Recorded at the Veliki Surduk Loess-Paleosol Sequence in Mošorin (Vojvodina, Serbia)
Basarin, B.1, Machalett, B.2, Marković, S. B.1, Milojković, N.1, Lukić, T.1
1Department of Geography, Tourism and Hotel Managment, Faculty of Sciences, University of Novi Sad, Serbia
2Humboldt-University of Berlin, Department of Geography, Unter den Linden 6, D-10099 Berlin, Germany
One of the most intriguing features of loess paleosol successions is the change of color. Observed changes in colors can be used as paleoclimatic proxies due to the accepted interpretation that paleosols formed under warmer and generally wetter conditions when the rates of dust deposition were diminished (e.g. Yang et al. 2001; Ding et al., 2002; Vidic et al, 2004).
Loess-paleosol sequences in the Vojvodina region (Serbia) are thought to be among the oldest and most complete Pleistocene terrestrial paleoclimatic records in Europe (Marković et al., 2006, 2007, 2008, 2009). Mošorin loess-paleosol sequence is situated in the north of the Titel loess plateau, and is characterized by considerable high sedimentation rates during the last three glacial cycles.
For samples taken at 5 cm interval, dry and wet colors were determined using Munsell soil color chart. In order to present the change of color of the loess and interstratified paleosols on a curve throughout the profile, the colors in Munsell notation were quantified in RGB color system. For each wet and dry color the RGB values were obtained. Munsell colors were also converted in L*a*b* color space.
Based on determined wet and dry colors soil development indices, rubification and melanisation, were calculated. Rubification and melanization indices were calculated following Harden (1982), using spread sheet developed by Taylor (1988), Vidić and Lobnik (1997). Rubification is defined as formation of goethite and hematite crystals suspended in groundmass, which give the soil bright red color. Melanization indicates accumulation of humus and humic substances in the soil.
Increased values of rubification were determined in pedocomplexes while in loess layers, which were considered as parent material, these indices equal 0. Similar results were obtained in other loess-paleosol sequences of Eurasian continent (eg. Vidic et. al., 2004, Marković et al., 2009). Sharp contrast in paleoclimatic proxies between loess layers and intercalated pedocomplexes demonstrate climate fluctuations from dry and relatively cold to humid and warmer conditions. The redness of soil is usually connected with the amount of pedogenic hematite in soils and can be interpreted as paleoenviromental proxy (Schwertmann, 1993). Environmental conditions which cause the formation of pedogenic hematite are consistent with hot environments with seasonal alternations of humidity (Torrent et al., 1982, Yang et al., 2001).
Based on the results obtained it can be concluded that during the last three interglacial cycles environmental conditions were similar to those prevailing today.