The not trivial subdivision of nappes in the Lower Pennine domain of the Central Alps (Riviera Valley, Swiss Alps)

Schenker, Filippo and Ambrosi, Christian and Scapozza, Cristian and Castelletti, Claudio and Maino, Matteo (2016) The not trivial subdivision of nappes in the Lower Pennine domain of the Central Alps (Riviera Valley, Swiss Alps). In: Geophysical Research Abstracts Vol. 18, EGU2016-3083, 2016 EGU General Assembly 2016, Vienna, Austria.

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Abstract

We present new data of the geological map of the Osogna sheet in the Southern Swiss Alps (Swiss National Map no. 1293) that extends N-S from Biasca to Claro and W-E from Lavertezzo to the Pizzo di Claro, respectively. The area mapped at the 1:10’000 scale is located in the Lepontine dome and includes, from core-to-carapace, the gneissic nappes of the Leventina, Simano, Adula/Cima-Lunga and Maggia. These nappes derive from the same post-Variscan gneissic basement complicating their lithological distinction and making difficult to recognize their boundaries. In particular, the boundary between the Leventina and the Simano gneisses is difficult to recognize. In previous work, this boundary was traced within leucogneisses by joining a carbonate lens with quartzite, amphibolite or paragneiss lenses. Nevertheless, quartzites are absent in the mapped area and amphibolite and paragneiss lenses are vertically distributed in the tectonostratigraphy and do not form a single folded horizon. Furthermore, no significant strain gradient related to top-to-the-foreland shearing has been observed between these two units, also when paragneisses and amphibolites were present. Therefore, we present evidence that the top-to-the-foreland deformation between the Leventina and the Simano units was more distributed that commonly assumed, questioning the allochthonous character of the Simano unit.

Item Type:	Article in conference proceedings or Presentation at a conference (Poster)
Subjects:	Physical sciences > Geology Physical sciences > Geology > Earth science Physical sciences > Geology > Earth science > Geoscience
Department/unit:	Dipartimento ambiente costruzioni e design > Istituto scienze della terra
Depositing User:	Filippo Luca Schenker
Date Deposited:	15 Jan 2018 08:54
Last Modified:	15 Jan 2018 08:54
URI:	http://repository.supsi.ch/id/eprint/9118

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