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Ash admixtures formed during the loss on ignition (LOI) procedure and their impact on laser textural analysis results

Tsvirko Dmitry, Tołoczko Wojciech, Kittel Piotr

Geology, Geophysics and Environment

2024

Vol. 50, no. 2

155--174

We present an experimental study that explores the feasibility of using the ash from biogenic deposits for laser textural analysis. The results have demonstrated that conducting ash textural analysis without prior chemical treatment can lead to unreliable results. Among other things, this is due to the “contamination” of the ash with aggregates formed by metal oxides and carbonates during ignition (LOI550 procedure) in a muffle furnace. Metal oxides and carbonates can create aggregates with silt and clay grains. As a result, the material coarsens, mainly to very coarse and coarse silt fractions. It is illustrated that the ash after LOI550 has been contaminated with oxides and carbonates of iron (Fe), potassium (K), magnesium (Mg), calcium (Ca), manganese (Mn), sodium (Na), zinc (Zn), lead (Pb) and copper (Cu). Thus, we suggest a method of using 10% HCl to purify the ash from metal oxides and carbonates (so-called ash purification procedure or APP). The analysis in this paper focuses on the grain size composition of ash, both untreated and HCl-treated. The obtained results have been compared and discussed in detail.

A Tree-Ring chronology from Allerød–YD transition from Koźmin (Central Poland)

Krąpiec Marek, Szychowska-Krąpiec Elżbieta, Barniak Joanna, Goslar Tomasz, Kittel Piotr, Michczyńska Danuta J., Michczyński Adam, Piotrowska Natalia, Rakowski Andrzej, Wiktorowski Damian

Geochronometria

2020

Vol. 47, no.1

101--111

Subfossil trunks of pine (Pinus sylvestris L.) from the Late Weichselian were discovered in the site Koźmin in the Koło Basin, central Poland (Dzieduszyńska et al., 2014a). Another part of organic sediments with trunks was excavated in the frame of the research project. Altogether 224 samples from Koźmin were analysed dendrochronologically; they represented generally young trees, 40 to 70 years old. Based on the most convergent sequences, the chronology 2KOL_A1 was produced, 210 years in length. With the wiggle-matching method, it was dated to ca. 13065–12855 cal BP. Dendrochronological dating of trunks buried in organic sediments, most of which occurred in situ, revealed that tree deaths occurred successively, over more than 100 years. That could have been due to unfavourable climatic conditions, as well as extreme events, e.g. strong winds.