An episode of mountain building that ended about 1000 Ma ago and affected an area extending from what are now Columbia and Mexico, eastern N. America, eastern Greenland, and Scandinavia (where it is known as the Dalslandian, or Gothian orogeny). It is well exposed in the south-eastern part of the Canadian Shield along a line extending north-east from the northern shore of Lake Huron. It was caused by plate motions associated with the opening of the Atlantic and leading to the displacement of rocks in a north-westerly direction.