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
San Rafael orogeny San Rafael orogeny The San Rafael orogeny was an orogeny that affected parts of western Argentina and Chile during the Late Paleozoic. The resulting orogenic belt has a NW-NNW curved form. The San Rafael orogeny might have been linked with the roughly contemporary Gondwanide orogeny of eastern Argentina. Parts of the Choiyoi Group sediments were deformed by the San Rafael orogeny. During the Neogene ancient faults related to the San Rafael orogeny conditioned the geometry of the blocks affected by the Andean orogeny. Some of the plutons of the Elqui-Limarí Batholith were emplaced a context of crustal thickening derivative of