What is Caledonian orogeny?
[[File:Caledonides EN.svg|thumb|350px|Positions of the branches of the Caledonian mountains at the end of the Caledonian orogeny. Present coastlines in gray. Later on, the [[Atlantic Ocean]] opened and the different parts of the orogenic belt moved apart.<ref>Reconstruction based on Matte (2001); Stampfli ''et al.'' (2002); Torsvik ''et al.'' (1996) and Ziegler (1990)</ref>]] [[File:Wave-cut platform below Allt Wen - geograph.org.uk - 1751658.jpg|thumb|right|280px|Remains of the orogeny at [[Aberystwyth]], [[Wales]]]] The '''Caledonian [[orogeny]]''' was a [[orogeny|mountain building era]]. It left its mark in the northern parts of the [[British Isles]], the [[Scandinavian Mountains]], [[Svalbard]], eastern [[Greenland]], northern [[Europe]] and the eastern [[United States]].<ref>Cocks L.R.M. & Torsvik T.H. 2006. European geography in a global context from the Vendian to the end of the Palaeozoic. In Gee D.G. & Stephenson R.A. (eds) ''European lithosphere dynamics''. Geological Society of London Memoirs '''32''', pp. 83–95.</ref><ref>Jones K. & Blake S. 2003. ''Mountain building in Scotland''. {{ISBN|0-7492-5847-0}}</ref> The events occurred from the [[Ordovician]] to early [[Devonian]], roughly 490{{ndash}}390&nbsp;million years ago (mya). It was caused by the closure of the [[Iapetus Ocean]] when the continents and lands of [[Laurentia]], [[Baltica]] and [[Avalonia]] collided. The Caledonian orogeny is named after [[Caledonia]], the [[Latin]] name for [[Scotland]]. The name is not used for an absolute period of time: it applies only to the series of mountain-building events. Part of the mountain chain ended up in modern [[North America]], where it is called the [[Acadian orogeny]] (see [[Appalachian Mountains]]). == Stages == The Caledonian orogeny was one of several orogenies that would eventually form the supercontinent [[Pangaea]] later in the [[Palaeozoic]] [[era]]. The main phase of the Caledonian orogeny happened from about 425 to 395 million years ago. Continental collision started in the mid [[Sil