The tectonic evolution of the Penninic units and the distal European margin during Late Cretaceous and Paleogene times is very well constrained in the Western and Central Alps. In the Eastern Alps the evolution of these units is discussed controversially. Three main problems are discussed: (1) The continuation of the Northpenninic oceanic basin (Valais) towards east; (2) The continuation of the Middlepenninic microplate (Brianconnais) towards east; (3) The paleogeographic position of the Rhenodanubian Flysch basin.
(1) Many palinspastic reconstructions display a Northpenninic position of the Glockner Nappe within the Tauern Window; the Matrei Zone above is supposed to be Southpenninic. Because no continental units were observed between the Glockner Nappe and the Matrei Zone, it is assumed that the Middlepenninic only extends to the area of the Engadine Window. Other observations suggest that both the Glockner Nappe and the Matrei Zone are Southpenninic. (2) Older models suggested that the Zentralgneis in the central Tauern Window with its sedimentary cover (Venediger Nappe) forms the continuation of the Brianconnais. Recent tectonic reconstructions have shown that the Venediger Nappe was part of the distal European margin. However, it was also suggested that certain gneiss lamellae, above the Venediger Nappe, may derive from the Brianconnais. (3) The paleogeographic position of the Rhenodanubian Flysch basin is supposed to be Northpenninic by a great number of scientists.