Engadin window

The Engadin window or is a tectonic window that exposes penninic units lying below the austroalpine units in the alpine nappe stack. It has a roughly elliptical shape with the long axis striking northwest-southeast and dimensions of 55 x 17 km.
The rocks cropping out in the Engadin window are weakly metamorphosed sediments of middle Jurassic to Eocene age. Most of them are interpreted as deposits from turbidites. They are seen as part of the penninic units similar to the rocks that make up large portions of the Switzerland. Furthermore, the sediments are attributed to the Valais ocean, the Briançonnais microcontinent, and the Piemont-Liguria Ocean. The metamorphic overprint was caused by the closure of the Valais and the Piemont-Liguria during the Paleogene part of the Alpine orogeny. The rocks experienced low-temperature-high-pressure overprint which reached the blueschist facies.

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