Quarzite del Mèdola

Représentation et statut

Couleur CMYK

(0%,0%,19%,16%)

Couleur RGB

R: 215 G: 215 B: 175

Rang

Formation lithostratigraphique

Usage

Ce terme est en usage.

Status

terme informel

Nomenclature

Deutsch

Mèdola-Quarzit

Français

Quartzite du Mèdola

Italiano

Quarzite del Mèdola

English

Mèdola Quartzite

Origine du nom

Pizzo Mèdola (TI)/(Italia)

Variantes historiques

Quarzite und Glimmerquarzite, +/- kalkhaltig [Pizzo Medola] (Günthert 1958), --- (Burckhardt & Günthert 1957, Greco 1985, Huber 1981), Quartzite du Mèdola (Matasci 2009), Mèdola quartzite (Matasci et al. 2011 p.264)

Description

Épaisseur

Epaisseur variable: seulement 10-20 m près de Campo (Matasci et al. 2011).

Géographie

Extension géographique

Lepontin

Paléogéographie et tectonique

Type de protolithe

• sédimentaire

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: 3.4.4 The Mèdola quartzite

This is also a very characteristic lithology, well exposed at the Pizzo Mèdola (pt 2957 on the Swiss-Italian border; 678.620/137.730), where it is overthickened by folding (see below Sect. 4.6). We choose this peak as type locality. It consists in a regular and uniform alternation of centimetric to decimetric beds of white to light grey quartzites and darker calcareous sandstones, sometimes with thin layers of dark micaschists. At several places these quartzites have already drawn the attention of geologists who mapped them with a distinct signature (Burckhardt and Günthert 1957; Greco 1985; Huber 1981). A conspicuous level of quartzites has also been mentioned in the lower part of the Teggiolo calcschists father SW in Italy by Canepa (1993). This formation, more uniform than the Piano delle Creste sandstone, is easy to recognize and quite continuous, although its thickness varies considerably. It becomes thinner near Campo where it is only 10–20 m thick before it is cut at the 2,100 m elevation by the base of the wildflysch. It reappears in the Vanzèla cliffs 1 km N of Campo, forming the core of a large and complex isoclinal anticline (around 683.5/142.7; see below Sect. 4.6 and Fig. 10). It is possible that the base of the Mèdola quartzite is unconformable. This would explain the thinning of the Pianasciom calcschist near Campo and its probable disappearance on the boundary crest. This point needs more detailed studies in the slopes above Campo and around the Kalberhorn.