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
Malagasy orogeny Madagascar as the boundary between the African and India terranes. Malagasy orogeny Malagasy orogeny is the name given to the Ediacaran to Cambrian orogeny that resulted as India collided with the already amalgamated African continent that consisted of Azania and the Congo-Tanzania-Bangweulu Block. The orogeny affected the parts of the East African Orogen that are now found in southern India, Madagascar and central Arabia. The term "Malagasy orogeny" was introduced by for the orogenisis between India and a series of Gondwanan cratonic blocks in present-day Africa (Congo/Tanzania/Bangweulu/Azania). In their reconstruction, India collided with Australia/Mawson in the Kuunga orogeny before the