Elemental geochemistry of freshwater snail shells: palaeolimnology of a Holsteinian (MIS 11) deposit from eastern Poland

Abstract

The elemental shell chemistry of two freshwater snails, Viviparus diluvianus (Kunth) and Valvata piscinalis (Müller) was studied for palaeoenvironmental purposes. The shells were collected from lake sediments from five Holsteinian (Marine Isotope Stage 11) sites in eastern Poland (Ossówka, Hrud II, Roskosz, Ortel Królewski and Szymanowo) and analysed for Ca, Mg, Sr, Mn and Fe. The Fe/Mn molar ratio was used as a redox indicator, with lower values (and high Mn concentrations) pointing to suboxic conditions. These occurred in the beginning of the Taxus zone and during the transition between the Taxus and Pinus‐Larix zones at Ortel Królewski, and in the Holsteinian thermal maximum (Carpinus‐Abies zone) at Roskosz Lake. Strongly reducing conditions, indicated by increased Fe and Fe/Mn values, prevailed at Ortel Królewski palaeolake in the middle of the Taxus zone, in the Pinus‐Larix zone and in the upper part of the Roskosz sequence. Indicators of anoxia correlate with eutrophic conditions, enhanced productivity and oxygen consumption due to organic matter decay. The most distinct environmental changes in the records are comparable to other central and northern European records and to the main climatic oscillations during the Holsteinian, inferred from palynological, malacological and isotopic data.

Palaeotemperature estimation in the Holsteinian Interglacial (MIS 11) based on oxygen isotopes of aquatic gastropods from eastern Poland

“…In this study, the past water temperature reconstruction based on oxygen isotopes of freshwater snail shells is verified by pollen Nitychoruk 1995, 1996;Krupiński 1995Krupiński , 2000Bińka et al 1997), molluscs (Lindner et al 1991;Albrycht et al 1995;Skompski 1996;Szymanek 2012Szymanek , 2013Szymanek , 2014a and geochemistry (Nitychoruk 2000;Nitychoruk et al 2005;Szymanek 2016Szymanek , 2017Szymanek et al 2016). The occurrence of characteristic plants combined with the characteristic regional floristic succession reveal air temperature changes through the Holsteinian Interglacial (Krupiński 1995;Nitychoruk 2000), whereas the mollusc assemblages (Albrycht et al 1995;Szymanek 2012Szymanek , 2013Szymanek , 2014a, oxygen and carbon isotopes (Szymanek 2016;Szymanek et al 2016) and shell elemental composition of V. diluvianus and V. piscinalis (Szymanek 2017) allow the definition of environmental conditions in the studied water bodies.…”

“…The occurrence of characteristic plants combined with the characteristic regional floristic succession reveal air temperature changes through the Holsteinian Interglacial (Krupiński 1995;Nitychoruk 2000), whereas the mollusc assemblages (Albrycht et al 1995;Szymanek 2012Szymanek , 2013Szymanek , 2014a, oxygen and carbon isotopes (Szymanek 2016;Szymanek et al 2016) and shell elemental composition of V. diluvianus and V. piscinalis (Szymanek 2017) allow the definition of environmental conditions in the studied water bodies. Because this study deals with lakes which no longer exist there still remain some doubts in their catchment characteristics (cf., Candy et al 2016), and the discussion may appear somewhat subjective at some points, but it is still significant for the interglacial record, which in general is devoid of oxygen isotope temperature reconstructions.…”

“…Moreover, some changes in the water oxygenation connected with varied productivity levels and trophic conditions occurred in this interval, being expressed in the changes of Fe and Mn concentrations in mollusc shells. After the phase of more eutrophic conditions with possible bottom-water anoxia in the middle part of Taxus Zone, somewhat higher oxygen concentration was noted in the transition between the Taxus and Pinus-Larix zones (Szymanek 2017).…”

“…The ecology of the studied palaeolakes has been based on multi-proxy palaeobotanical (Lindner et al 1991;Nitychoruk 1995, 1996;Krupiński 1995Krupiński , 2000Bińka et al 1997;Marciniak 1998), malacological (Lindner et al 1991;Albrycht et al 1995;Skompski 1996;Szymanek 2012Szymanek , 2013Szymanek , 2014a and geochemical analyses (Szymanek 2016;2017;Szymanek et al 2016), which yielded basic information about their hydrological regime (water level changes, water movements/wave action, depth conditions etc. ), the aquatic vegetation, productivity and trophic conditions.…”

“…This phase was followed by a shallow lake phase with prolonged residence time and dense bulrushes and reeds in its littoral areas evidenced by abundant pulmonate gastropods Gyraulus albus, Lymnaea stagnalis and Acroloxus lacustris (Szymanek 2013). Increased δ 13 C and Fe/Mn values in V. diluvianus and V. piscinalis shells point to higher productivity level and oxygen consumption due to organic matter decay at that time (Szymanek 2017). Depletion of 13 C in the uppermost part of the succession is related to limited vegetation and deepening of the lake (Szymanek 2016;Szymanek et al 2016).…”