Heights–Upper Enns Valley–Schober Pass–Mürz Valley Alps–Semmering–southern Vienna Basin. The Central Alps and Southern Alps are separated from one another by the Southern Longitudinal Valley (südlichen Längstalzug) Puster Valley (Rienz Valle–Toblach Field–upper Drava (Drau) Valley)–Drava Valley–Klagenfurt Basin–Meža (Mieß), or the Periadriatic Seam, which is not entirely identical with the Southern Longitudinal Trough. Geomorphology The range has the highest summits in the Eastern Alps and is the most glaciated. In the transition zone between the East und West Alps its peaks clearly dominate the region to the west (Piz d'Err, Piz Roseg). On the perimeter, however, there are also less high, often less rugged mountain chains, like the Gurktal Alps and the eastern foothills. The Eastern Alps is separated from the Western Alps by a line from Lake Constance to Lake Como along the Alpine Rhine valley and via the Splügen Pass. Geology The Central Alps consist mainly of the gneiss and slate rocks of the various Austroalpine nappes (Lower and Upper Austroalpine), with the exception of the Hohe Tauern and Engadine windows, where they are composed mostly of Jurassic rock and limestones and, locally, (Bergell and Rieserferner) also of granite. The Austroalpine nappes are thrusted over the Penninic nappe stack. Massifs of autochthonous, crystalline rock, which hardly moved at all during Alpine folding, do not occur in the Central Alps – unlike the case in the Western Alps. The aforementioned granite intruded near the fracture zone of the Periadriatic Seam. The Western Alps do not have this division into the Northern Limestone Alps, Central Alps and Southern Limestone Alps. The Austroalpine submerges itself at the eastern edge of the Alps under the Tertiary sediments of the Alpine Foreland in the east and the Pannonian Basin. This fracture zone exhibits active volcanism (e.g. in the Styrian thermal region). Alpine Club classification The Central Eastern Alps also comprise the following ranges of the West Eastern Alps according to AVE classification, which geologically belong to the Southern Alps and are also subsumed under the Western Limestone Alps division.: The Ortler Alps as well as the Sobretta-Gavia Group are also sometimes classified with the Central Alps, because they lie north of the geological fault of the Periadriatic Seam; in a general regional geographic sense, however, they are seen as part of the Southern Limestone Alps, because they are found south of the longitudinal trough Veltlin (Adda)–Vintschgau (Etsch). Also in terms of rock, the Ortler main