strati.ch - Lithostratigraphic Lexicon of Switzerland

Representation and status

Tectonic unit (resp. main category)

Kind of protolith

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

p.96: The Vinschgau Shear Zone represents the structurally highest unit of the Campo Nappe Complex and constitutes a greenschist-facies Alpine mylonitic belt with a thickness of up to 2–3 km that accommodates W-directed thrusting of the Ötztal Nappe Complex in the area north of the Vinschgau Valley floor (Schmid & Haas 1989). South of the valley floor and in the lowermost Val Müstair, the same mylonitic belt accommodates WNW-directed thrusting of the easternmost part of the Umbrail-Terza Slice Complex over the S-charl-Sesvenna Nappe (Conti 1997). The protoliths of this mylonitic belt include pre-Permian basement, sericite-rich Permo-Triassic siliciclastic metasediments and rare occurrences of mid-Triassic carbonates that are part of the Campo Nappe Complex. The fact that the Vinschgau Shear Zone directly overlies both the rest of the Campo Nappe Complex and the easternmost parts of the S-charl-Sesvenna Nappe shows that, at a large scale, the Campo Nappe Complex and the S-charl-Sesvenna Nappe occupy about the same tectonic position within the Upper Austroalpine nappe stack.