The aim of this project is to extend the knowledge about the occurrence and dispersal of the cryptotephras in northern Poland using annually laminated lake sediments.
Cryptotephra is defined as a low concentration of volcanic glass shards or phenocrystals – the main components of tephra – that is nonvisible to the naked eye (Lowe 2011).
Tephra studies are essential for the dating and synchronisation of paleoenvironmental reconstructions and provide information about the ash dispersal of past volcanic eruptions, which is important for future natural hazard assessments. Intensive tephra studies during the past decades in western Europe have proved the importance of such time markers and are so far outstanding from the knowledge about volcanic ash occurrences in Poland.
Annually laminated (varved) lake sediments are composed of two (or more) laminae representing a seasonal cycle of sedimentation and accumulate under certain conditions (Zolitschka et al. 2015). Varves provide high-resolution and calendar year time scales for paleoenvironmental research. They were considered to be uncommon in Poland until recently (e.g. Tobolski 2000; Tylmann et al. 2013; Wulf et al. 2013).
Hypothesis:
- cryptotephras occur more commonly in northern Poland than previously proposed, that those can be detected using appropriate novel methods (μ-XRF sediment core scanning, high-resolution sediment sampling and processing);
- annually laminated lake sediments in a main W-E and subordinate S-N transect are best suitable for tracking the distal tephra dispersal.
Annually laminated sediments (varves) may be useful for tracking cryptotephras
- Lowe D.J., 2011. Tephrochronology and its application: a review. Quaternary Geochronology 6(2), 107–153.
- Tobolski K., 2000. Przewodnik do oznaczania torfów i osadów jeziornych. PWN, pp. 507.
- Tylmann W., Zolitschka B., Enters D., Ohlendorf C., 2013. Laminated lake sediments in northeast Poland: distribution, preconditions for formation and potential for paleoenvironmental investigation. Journal of Paleolimnology 50(4), 487–503.
- Wulf S., Ott F., Słowiński M., Noryśkiewicz A.M., Dräger N., Martin-Puertas C., Czymzik M., Neugebauer I., Dulski P., Bourne A.J., Błaszkiewicz M., Brauer A., 2013. Tracing the Laacher See Tephra in the varved sediment record of the Trzechowskie palaeolake in central Northern Poland. Quaternary Science Reviews 76, 129–139.
- Zolitschka B., Francus P., Ojala A.E.K., Schimmelmann A., 2015. Varves in lake sediments – a review. Quaternary Science Reviews 117, 1–41.