Acadian Orogeny

A mountain-building event that affected the northern portion of the Appalachian Geosyncline from present-day New York to Newfoundland during the Devonian Period (408 to 360 million years ago). Orogenic activity began during the Early Devonian in Gaspé, spread westward throughout Devonian time, and affected the western margins of the geosyncline in Late Devonian time.