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Markus Fiebig, Institute of Applied Geology (Austria)
Philipp Haeuselmann, Swiss Institute for Speleology and Karst Studies (Switzerland)
Kurt Stuewe, University of Graz, Institute for Earth Science (Austria)
Philippe Audra, Université Nice Sophia Antipolis (France)
Derek Fabel, University of Glasgow (United Kingdom)
Bernhard Grasemann, Universität Wien, Center for Earth Science (Austria)
Andrej Mihevc, Karst Research Institute ZRC SAZU (Slovenia)
Diana Sahy, Universität für Bodenkultur Wien, Institute for Applied Geology (Austria)
Thomas Wagner, University of Graz, Institute for Earth Science (Austria)
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Sedimentary records provide important information about climatic, tectonic, and environmental histories. To put this information into the correct framework, dating of the sediments is necessary. Burial age dating provides a new tool to date Pliocene and Pleistocene sediments and thus opens new chances to unravel the complicated history of erosion and deposition in terrestrial environments. Quartz grains exposed to cosmic radiation at the surface accumulate 26Al and 10Be with a definite ratio of 6.8:1. When the quartz grains are buried, the different half-live of these radioactive nuclides causes the ratio to decrease with time. This decrease is the key to determine the time since the grain was buried.
Results based on cosmogenic nuclide data from the central Northern Alpine Foreland point to erosion rates of about 0.1 mm/a for the last million years and 0.03 mm/a before (e.g. Häuselmann et al. 2007). In the Western Alps, the incision of the Aare valley is estimated to be 0.14 mm/a during the Pliocene and 1.1 mm/a during the middle (and upper) Pleistocene (Häuselmann & Granger 2005). For the Eastern Alps, no investigations based on cosmogenic nuclide data are published so far. Estimations based on other data point to slow incision rates during the Miocene and an increase during the Pliocene and Pleistocene (e.g. Kuhlemann et al. 2001). New results for the Eastern Alps based on cosmogenic nuclide data are now in preparation.
References
Häuselmann, P., Fiebig, M., Kubik, P. & H. Adrian (2007): A first attempt to date the original Deckenschotter of Penck and Brckner with cosmogenic nuclides. Quaternary International, 164-165: 33-42.
Häuselmann, P. & Granger, D. (2005): Dating of caves by cosmogenic nuclides: method, possibilities, and the Siebenhengste example (Switzerland). Acta Carsologica, 34(1): 43-50.
Kuhlemann, J., Frisch, W., Dunkl, I., Székely, B. & Spiegel, C. (2001): Miocene shifts of the drainage divide in the Alps and their foreland basin. - Z. Geomorph. N.F., 45 (2): 239-265.
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