serval:BIB_8ECE9B0810F9
The Soja and Luzzone-Terri nappes: discovery of a Briançonnais element below the front of the Adula nappe (NE Ticino, Central Alps)
10.5169/seals-284223
Galster
F.
author
Epard
J.-L.
author
Masson
H.
author
article
2010
Bulletin de la Société Vaudoise des Sciences Naturelles
0037-9603
journal
92
61-75
The classical Soja nappe, in NE Ticino, actually consists of two distinct tectonic units with verydifferent stratigraphic contents: (1) The smaller one, in the Val Soi (the type-locality), is by definitionthe Soja unit s.str.. It is pinched between Simano and Adula and consists of various Paleozoic gneissesand a dolomitic Triassic cover analogous to the Triassic of other Lower Penninic nappes. (2) The largerone extends along the Lago di Luzzone and continues eastwards through the Piz Terri mountain. Wename it the Luzzone-Terri nappe. It consists of: (a) a paragneiss series that presents striking similaritieswith the Permian of the Zone Houillère in Valais; (b) a Triassic cover typical of the Briançonnaisdomain where one clearly recognizes the St-Triphon Formation and other characteristic units of theBriançonnais Triassic; (c) a thick series of black calcschists and metapelites of Liassic age, similarto the cover of the neighbouring Gotthard massif. This stratigraphic superposition of a Liassic seriesof Helvetic type on a Briançonnais Triassic is unique in the Alps and has important paleogeographicconsequences. It is difficult to reconcile this observation with speculative reconstructions that proposean original position of the Briançonnais domain far from the Helvetic basins. Morover the Briançonnaischaracter of its Triassic series indicates an ultra-Adula origin of the Luzzone-Terri nappe.
Soja, Luzzone, Piz Terri, Adula, Ticino, Penninic, Briançonnais Triassic, Central Alps
eng
60_published
peer-reviewed
University of Lausanne
mailto:serval_help@unil.ch
http://www.unil.ch/serval
http://serval.unil.ch/disclaimer
https://serval.unil.ch/notice/serval:BIB_8ECE9B0810F9