«Gneiss plagioclasici a biotite»

Représentation et statut

Index

GO

Couleur CMYK

(0%,0%,0%,100%)

Rang

Formation lithostratigraphique

Usage

Ce terme est en usage.

Status

statut inconnu

Nomenclature

Deutsch

«Schiefriger Biotitplagioklasgneis»

Italiano

«Gneiss plagioclasici a biotite»

Origine du nom

Schiefriger Biotitplagioklasgneis (Reinhard 1964), Gneiss biotitico-plagiodasici (Boriani et al. 1990)

Description

Description

Gneiss plagioclasici a biotite, da lenticolari a scistosi, spesso con muscovite et feldspato alcalino, localemente con orneblenda

Hiérarchie et succession

Unité hiérarchiquement supérieure

• Rocce magmatiche paleozoiche (metagraniti)

Âge

Âge au sommet

• Silurien

Note sur le sommet

Permian?

Âge à la base

• Ordovicien

Géographie

Extension géographique

Val Veddasca, Val Cannobina.

Références

Révision

Boriani A., Giobbi Origoni E., Borghi A., Caironi V. (1990) : The evolution of the "Serie dei Laghi" (Strona-Ceneri and Scisti dei Laghi): the upper component of the Ivrea-Verbano crustal section; Southern Alps, North Italy and Ticino, Switzerland. Tectonophysics 182, 103-118

A muscovi te-rich paragneiss variety occurs in Val Veddasca ("Schieferiger Biotitplagioklasgneis ± Muskovi t fiihrend"; Reinhard. 1964) and in Val Cannobina (shown partly as "Gneiss biotitico-plagiodasici" and partly as "Gneiss minuti" on the Geological Map of the Verbania area by Boriani et al., 1977). It probably represents a more clay-rich facies of the Strona-Ceneri sediments, heteropic with the Ceneri gneiss. Ca-silicate nodules do not occur in this variety.