Formation of fold nappes

Fold nappes are large scale recumbent folds with amplitudes sometimes more than 10 kilometers. Fold nappes have been recognized in the Alps since more than 150 years, but the mechanical process by which they form is until now not fully understood. We study the dynamics of fold nappe formation (Figure 1) with similar numerical models that are used to study buckle-folding. The aim of this research is to understand the basic process of fold nappe formation in order to allow a physically based tectonic reconstruction of the fold nappes in the Western Swiss Alps, such as the Morcles nappe.

Figure 1: Representative cross section of the Morcles nappe which is a large scale recumbent fold with a prominent overturned limb (Ramsay, 1981)(left). Finite element simulation of a basic scenario of fold nappe formation under far-field simple shear  (right).


Stefan Schmalholz

PhD students
Yoann Jaquet

Géopolis - CH-1015 Lausanne
Tel. +41 21 692 43 06
Fax +41 21 692 43 05