This figure is taken from Otto Ampferer's "Über die Gleitformung der Glarner Alpen" published in 1934 in Sitzungsberichte der Akademie der Wissenschaften in Wien, Mathem.-naturw. Klasse, Abteilung I, 143. Band, 3. und 4. Heft. According to Ampferer the Helvetic nappes were emplaced by gravity gliding on the already eroded Infrahelvetic foreland. According to him the Glarus thrust followed an erosional surface ("Reliefüberschiebung"). This surface was intensely flattened by the overthrusting of the nappes.