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
Kaikoura Orogeny million years ago to the present day the rate of uplift has accelerated. Oligoclase and biotite schist have also been pushed to the surface of the Earth. In total about 20 kilometres of uplift has taken place during the Kaikoura Orogeny but most of this has been eroded away. Kaikoura Orogeny The Kaikoura Orogeny is a New Zealand orogeny that has given birth to the Southern Alps. It began 25 million years ago along the Alpine Fault. In this orogeny, the Southern Alps are being formed because the Pacific Plate is colliding with the Australian Plate, with a predominant oblique