'Late Quaternary lacustrine paleo-seismic archives in north-western Alps: Examples of earthquake-origin assessment of sedimentary disturbances'

To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.earscirev.2009.07.005 Byline: Christian Beck Keywords: lake sediments; slumps; homogenites; turbidites; earthquakes; Alps; Quaternary Abstract: The late Quaternary sedimentary fills of several lakes of the north-western Alps are revealed to be possible paleo-seismological 'archives' in a moderately active seismo-tectonic region. The strongest historically reported events can be correlated with specific layers, whose textures result from different processes: i) mass failures of sub-aqueous slope deposits (especially delta foresets) evolving into hyperpycnal currents influenced by seiche effects and/or multiple reflections on lake basin slopes; ii) in situ liquefaction and flowage; and iii) micro-fracturing. Based on identification of the sedimentary signature of a well-documented historical earthquake, the paleoseismic interpretation can be extrapolated back to 16,000yrs BP with a reconstruction of a time series and textural identification of slope failure-related turbidites (the most frequent earthquake signature). The obtained time series are compatible with historical seismicity in terms of recurrence interval. Author Affiliation: Laboratoire de Geodynamique de ChaA[R]nes Alpines, U.M.R. C.N.R.S. 5025, Universite de Savoie, 73 376 le Bourget du Lac Cedex, France Article History: Received 11 September 2008; Accepted 23 July 2009