Calcescisti del Teggiolo

Représentation et statut

Index

CT

Couleur CMYK

(0%,0%,18%,14%)

Couleur RGB

R: 220 G: 220 B: 180

Rang

Groupe lithostratigraphique

Usage

Ce terme est en usage.

Status

terme informel

Nomenclature

Deutsch

Teggiolo-Kalkschiefer

Français

Calcschistes du Teggiolo

Italiano

Calcescisti del Teggiolo

English

Teggiolo Calcshists

Origine du nom

Monte Téggiolo (Val Divedro, Italia)

Variantes historiques

Bündnerschiefer auct., Bündnerschiefer der Teggiolo-Mulde (Günthert 1958), Teggiolo calcschists (Matasci et al. 2011 p.264)

Hiérarchie et succession

Unités hiérarchiquement subordonnées

• Quarzite del Mèdola
• Calcescisti di Pianasciom
• Arenaria del Piano delle Creste

Limite inférieure

Contact érosif sur le Groupe d'Antabia resp. le socle d'Antigorio.

Âge

Âge au sommet

• Eocène moyen

Âge à la base

• Crétacé Tardif

Géographie

Extension géographique

Lepontin: Val d'Antabia, Val Bavona.

Références

Définition

Matasci Battista, Epard Jean-Luc, Masson Henri (2011) : The Teggiolo zone: a key to the Helvetic–Penninic connection (stratigraphy and tectonics in the Val Bavona, Ticino, Central Alps). Swiss J. Geosci. 104, 257–283

p.264: Above the Antabia group comes the main mass of the Teggiolo calcschists or Bündnerschiefer. It can be subdivided into two parts: (1) A lower part is made of regular, well-stratified lithostratigraphic units. In the Val Antabia its base truncates the two preceding cycles and reaches the Antigorio basement. This basal discontinuity is interpreted as a major stratigraphic gap. (2) An upper part is more disordered, sometimes even chaotic, and contains blocks of exotic rocks. We will demonstrate that it is a wildflysch (cf. Sects. 3.5 and 5.2). Its base is itself discordant and truncates the lower part on the left bank of the Bavona river above Campo at an elevation of about 2,100 m, unfortunately in bad outcrop conditions (approximately 684.300/141.750). The lower part of the Bündnerschiefer definitively disappears here and farther E (e.g. at the Alpe di Sevinèra or around the P. Castello) the wildflysch always lies directly on the Antabia group. For these reasons we will consider that the lower part forms a sedimentary cycle of its own (the third one) and the upper part belongs to a fourth cycle. Another unconformity probably also exists inside the lower part of the calcschists, but this point is not yet completely clear and will be discussed below. The third cycle is best developed in the Val Antabia where it is clearly subdivided into three well distinct, easily mappable, decameter- to hectometer-thick lithostratigraphic units that are conveniently considered as formations (Carreras and Jequier 2002). We give a short description.