A phase of mountain building affecting an area from the northern Appalachians in what is now New York State to the Bay of Fundy in maritime Canada (the name refers to the colony of Acadie in that region of French Canada). It occurred in the Devonian about 390 Ma ago, although the precise date and duration are uncertain, and was most intense east of the Taconic area (see taconic orogeny). It was caused by the westward movement of the Avalon terrane. See appalachian orogenic belt.