Taconic orogeny Taconic orogeny The Taconic orogeny was a mountain building period that ended 440 million years ago and affected most of modern-day New England. A great mountain chain formed from eastern Canada down through what is now the Piedmont of the East coast of the United States. As the mountain chain eroded in the Silurian and Devonian periods, sediments from the mountain chain spread throughout the present-day Appalachians and midcontinental North America. Beginning in Cambrian time, about 550 million years ago, the Iapetus Ocean began to close. The weight of accumulating sediments, in addition to compressional forces in the crust, forced
Pan-African orogeny collisions of several continental blocks. Furthermore, the Pan-African events are contemporaneous with the Cadomian orogeny in Europe and the Baikalian orogeny in Asia, and crust from these areas were probably part of Pannotia (i.e. Gondwana when it first formed) during the Precambrian. Attempts to correlate the African Pan-African belts with the South American Brasiliano belts on the other side of the Atlantic has in many cases been problematic. Orogenic belts comprising the Pan-African system include: Pan-African orogeny The Pan-African orogeny was a series of major Neoproterozoic orogenic events which related to the formation of the supercontinents Gondwana and Pannotia about