Tomül-Decke

Representation and status

Historical Variants: Tomül-Teildecke (Kündig 1926a), Tomüllappen (Wilhelm 1933, Jäckli 1947, van der Plas 1959), digitation du Tomül (Trümpy 1970), Tomül-Lappen (Bolli et al. 1980), Tomül Nappe (Berger & Mercolli 2007)

Description: Mächtige Abfolge des Walliser-Troges («nordpenninisch»), bestehend aus Bündnerschiefer, «Präflysch»- und Flysch-Ablagerungen.

Subordinate units

Age at top

Age at base

Geographical extent: Vom Nufenengebiet nach Norden zum Safiental, dann durch Viamala, Heinzenberg, Domleschg bis zum Stätzerhorn / Fulenberg.

Paleogeography

Valaisan Basin

Tectonic unit (resp. main category)

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

p.73: The Tomül Nappe, the highest of the “Bündnerschiefer” nappes rooting in the “Misox Zone”, locally has an ophiolite-bearing mélange at its base, overlain by an over 2 km-thick series of probably Cretaceous – Paleogene age (Steinmann 1994). In contrast with the Grava Nappe, the Tomül Nappe is not wrapped downwards around the front of the Adula Nappe. It can be followed eastward, below the Middle Penninic Schams Nappe Complex, and is then backfolded, together with the latter, around the front of the Suretta Nappe in order to come to lie in an overturned position on top of the Schams Nappe Complex in the upper limb of the Niemet-Beverin Backfold (Schreurs 1995, Schmid et al. 1997). This backfolded part of the Tomül Nappe is also referred to as “Arblatsch Flysch” (Ziegler 1956). East of Lenzerheide, the Tomül Nappe can be followed even further to the east and into the Prättigau Half-Window that exposes a very thick and multiply folded Cretaceous – Paleogene “Bündnerschiefer” and flysch sequence underlying the Middle Penninic Falknis and Sulzfluh nappes (Nänny 1948, Weh & Froitzheim 2001).