Subcrustal tectonic erosion in orogenic belts - a model for the late Cretaceous subsidence of the northern Calcareous Alps (Austria)

Analysis of the Upper Cretaceous to Eocene Gosau Group of the Northern Calcareous Alps (Austria) indicates rapid subsidence after a short interval of deformation, uplift, and erosion. Reconstructions of basement subsidence of >3000 m from the late Turonian (89 Ma) onward show a distinct shift of the deformation and subsidence from the northwest to the southeast together with a tilting of the Northern Calcareous Alps toward the north. Comparison with recent analogues suggest that subcrustal tectonic erosion due to the subduction of a topographic high of the South Penninic ocean may be the cause for this subsidence pattern. Tectonic erosion along ancient plate margins can be recognized by deformation and widespread erosion followed by regional subsidence not related to extension or flexural loading. -Author