strati.ch - Lexique lithostratigraphique de la Suisse

Représentation et statut

Variantes historiques: --- (Laurent 1967), Montées-Pélissier granite (Dobmeier 1996), Montées-Pélissiers peraluminous granite (Bussy et al. 2000, Capuzzo et al. 2003)

Unité hiérarchiquement supérieure

Âge au sommet

Âge à la base

Méthode de datation: 332 +/-2 Ma (U/Pb on zircon and monazite ; Bussy et al. 2000)

Termes génériques

Type de protolithe

Révision: Bussy François, von Raumer Jürgen, Capuzzo Nicola (2001) : Mont-Blanc, Aiguilles-Rouges massifs (External Massifs) - an example of polyorogenic evolution. Fieldtrip Guide 1, 53-84, Univ. Lausanne

p.66: The Montées-Pélissier granite is a vertical 3 km-long by 500 m-wide sheet-like pluton in tectonic contact with its country-rocks. A transpressive regime induced subhorizontal movements with extreme elongation, subsequently reoriented into subvertical displacements (Dobmeier 1998). The granite intruded syntectonically along ductile shear-zones during the transcurrent stage and recorded the subsequent vertical movements during cooling (Dobmeier 1996). Primary magmatic flow fabrics are mostly superimposed by low-T ductile to brittle deformation. The Montées-Pélissier granite is a fine-grained foliated two-mica monzogranite, which hosts rare biotite-rich restites, mafic microgranular enclaves and biotite-bearing lamprophyres. It is peraluminous with A/CNK values between 1.17 and 1.27; but primary muscovite is scarce and the mean representative point of its zircon morphological population plots at the limit between peraluminous and calc-alkaline granite fields in the typological grid of Pupin (1988).