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Origin of Turbidites In Deep Lake Geneva (France–Switzerland) In the Last 1500 Years
Journal article

Origin of Turbidites In Deep Lake Geneva (France–Switzerland) In the Last 1500 Years

  • Kremer, Katrina Department of Earth Sciences and Institute for Environmental Sciences, University of Geneva, Rue des Maraichers 13, 1205 Geneva, Switzerland
  • Corella, Juan Pablo Institute of Physical Chemistry Rocasolano (IQFR-CSIC), 28003 Madrid, Spain
  • Adatte, Thierry Institute of Earth Sciences, University of Lausanne, Geopolis, Lausanne, Switzerland
  • Garnier, Emmanuel Institut Universitaire de France (Paris) et UMR CNRS LIENSs Université de La Rochelle, France
  • Zenhäusern, gregor Forschungsinstitut zur Geschichte des Alpenraums (FGA), Stockalperschloss, Alte Simplonstrasse 28, 3900 Brig, Switzerland
  • Girardclos, Stéphanie Department of Earth Sciences and Institute for Environmental Sciences, University of Geneva, Rue des Maraichers 13, 1205 Geneva, Switzerland
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  • 2015-12-1
Published in:
  • Journal of Sedimentary Research. - Society for Sedimentary Geology. - 2015, vol. 85, no. 12, p. 1455-1465
Geology
English Abstract: 
Turbidites in lacustrine sediments are commonly used to assess the frequencies of flood events and/or earthquakes. Understanding the origin of those deposits is key to adequately assess the sources and triggers of such events in large lacustrine systems. Ca/Ti X-ray fluorescence core scanner and magnetic susceptibility values on sediment cores of the deep basin of Lake Geneva are used as a provenance indicator of the turbidites either from the Dranse or Rhone deltas or from the slopes not influenced by deltaic input. This tool is validated by mineralogical analyses (X-ray diffraction), major-, and trace-element geochemistry (X-ray fluorescence). Based on this discrimination method, the turbidites deposited in the central part of the deep basin can be classified regarding their origin. From all identified turbidites, four turbidites are chosen based on their large depositional area and volumes and are studied in more detail in order to better understand the processes leading to turbidite deposition in the deep basin. The age intervals of these turbidites were compared to the historical records of extreme events in the region of Lake Geneva. These turbidites can be related to extreme floods, earthquakes, and “spontaneous” delta collapses. The cause of two turbidites could not be identified precisely due to large dating intervals that did not allow attributing a specific historical event to the turbidite layer. Overall, this study provides a tool in classifying the turbidites in deep Lake Geneva and exemplifies that defining the cause of turbidites is complex although it remains a prerequisite for paleohydrology and paleoseismology studies.
Language
  • English
Open access status
closed
Identifiers
Persistent URL
https://sonar.ch/global/documents/247825
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