Umbrail–Terza-Schuppenkomplex

Representation and status

Color CMYK

N/A

Color RGB

R: 241 G: 239 B: 237

Rank

complex of tectonic slices

Validity

Unit is in Use

Status

valid

Nomenclature

Deutsch

Umbrail–Terza-Schuppenkomplex

Français

Complexe d'écailles de l'Umbrail–Terza

Italiano

Complesso di scaglie Umbrail–Terza

English

Umbrail–Terza Slice Complex

Origin of the Name

Piz Umbrail (GR)/(Italia)

Historical Variants

Umbrail-Decke, Umbrail–Terza Slice Complex (TK500 / Gouffon et al. 2024)

Description

Description

Oberostalpines Schuppenkomplex, das als parautochtone Sedimentbedeckung der S-charl-Sesvenna-Decke betrachtet wird.

Hierarchy and sequence

Subordinate units

• Umbrail–Chavalatsch-Schuppen
• Terza-Schuppe

Palaenography and tectonic

Tectonic unit (resp. main category)

• Umbrail-Terza

Kind of protolith

• tectonic

References

Definition

Gouffon Yves (Editor) (2024) : Tectonic Map of Switzerland 1:500000, Explanatory notes. Federal Office of Topography swisstopo, Wabern

p.97: This slice complex consists of two geographically separated parts. The smaller Terza Slice forms a simple klippe overlying the westernmost part of the Quattervals Nappe, comprising a slice of Norian to Rhaetian sediments detached from the incompetent Raibl Group (Somm 1965). The larger Umbrail-Chavalatsch Slices further to the east consist of a very complicated zone of imbrication (Schmid 1973), composed of two lithologically and tectonically separate units: firstly, of slices of Late Triassic sediments of the Raibl and Hauptdolomit groups, which were sheared off their original stratigraphical underpinnings, i.e., the S-charl-Sesvenna Nappe, and secondly, of pre-Mesozoic basement slices that are correlated with the tectonically higher basement of the Ötztal Nappe Complex that tectonically overlies the S-charl-Sesvenna nappe. Hence, these WNW-facing Umbrail-Chavalatsch Slices are interpreted as a basal imbrication underneath the Ötztal Nappe Complex, which overrode the sediments of the S-charl-Sesvenna Nappe, shearing them from their former stratigraphical base and imbricating them with basement slice pulled out of its base (Schmid 1973). In the east, this zone of imbrication with the Trupchun-Braulio Thrust at its base completely replaces the Quattervals Nappe and bends around into a NE–SW strike south of Sta. Maria. In the area of Piz Chavalatsch, the zone of imbrication directly overlies the Vinschgau Shear Zone of the Campo Nappe Complex and hence occupies a tectonic position identical to that of the Ötztal Nappe Complex (Conti 1997).