The Siviez Mischabel nappe

The Siviez Mischabel nappe: similar to the Mt Fort Nappe with an old basement, possibly the oldest in Valais, covered by a Permo-Carboniferous to Tertiary sedimentary sequence.  Part of this cover sequence remained attached to the basement in the Barrhorn series, allowing for a correlation with the Prealps Rigides Nappe.  This large nappe contains Permian granitic intrusions like the Randa gneiss, and 500 Ma old granites in Thyon.