Fig. 4From: Swiss and Alpine geologists between two tectonic revolutions. Part 1: from the discovery of nappes to the hypothesis of continental driftRise of basic magma along thrust planes at the beginning of orogenesis, as proposed by Argand (1916, Plate 3, Fig. 1). The concept was later referred to as “embryonic tectonics”. The basic rocks are associated with the main zone of thrusting, intruded in the form of sills and laccolitic bodies, rising along the developing inverted limb of the thrust nappeBack to article page