Editing Geology of the Alps (section)

===Subdivisions===
The Alps are often divided into [[Eastern Alps|Eastern]], [[Central Alps|Central]] and [[Western Alps]], even though the boundaries between these subdivisions are arbitrary. The division between the Eastern and Central Alps is approximately the line between [[St. Margrethen]], [[Chur]] and [[Sondrio]]; the division between the Central and Western Alps is unclear {{Harv|Pfiffner|2009|p= 25}}. The main [[suture (geology)|suture]] (big [[shear zone]]) in the Alps is called the [[Periadriatic Seam]] and runs through the Alps from east to west. This is the boundary between materials from the (former) European and [[Adriatic plate]] [[tectonic plate|plates]]. South of this line are [[Fold (geology)|fold]]ed and thrust units of the [[Southern Alps (geology)|Southern Alps]].

North of the Periadriatic seam, rocks from three main [[palaeogeography|palaeogeographic]] "domains" are found: the [[Helvetic (geology)|Helvetic or Dauphinois]], the [[Penninic]] and the [[Austroalpine]] domains. This subdivision is made according to the paleogeographical origins of the rocks: the Helvetic zone contains material from the European plate, the Austroalpine zone material from the Adriatic plate, the Penninic zone material from the domains that existed in between the two plates.<ref>See for a detailed subdivision of the geologic units in the Alps for example {{Harv|Schmid|Stefan|Fügenshuh|Kissling|2004}}, {{Harv|Compagnoni|2003}}, {{Harv|Pfiffner|2009|pp=25–27}}</ref>
[[File:Alps geology map en.jpg|thumb|none|800px|Simplified geological map of the Alps, showing the tectonic subdivision and the largest geological structures. Some details are based on controversial assumptions.]]