Sonoma orogeny Sonoma orogeny The Sonoma orogeny was a period of mountain building in western North America. The exact age and structure of the Sonoma orogeny is controversial. The orogeny is generally thought to have occurred during the Permian / Triassic transition, around 250 million years ago, following the Late Devonian Antler orogeny. The Sonoma orogeny was one of a sequence of accretionary events along the Cordilleran margin, possibly caused by the closure of the basin between the island arc of Sonomia and the North American continent. Evidence of this event has been reported throughout western North America, but most distinctly in
Malagasy orogeny 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 formation of Gondwana. They identified the Betsimisaraka suture in eastern