Opening of the North Atlantic Ocean Plateau (off Norway), Faroe-Shetland Basin, Hebrides, Outer Moray Firth and Denmark. The supercontinent known as Pangea existed during the late Paleozoic and early Mesozoic eras and began to rift around 200 million years ago. Pangea had three major phases of breakup. The first major phase began in the Early-Middle Jurassic, taking place between North America and Africa. The second major phase of breakup began in the Early Cretaceous. The South Atlantic Ocean opened around 140 million years ago as Africa separated from South America, and about the same time, India separated from Antarctica and Australia, forming the central Indian Ocean.
Intermontane Islands Intermontane Islands The Intermontane Islands were a giant chain of active volcanic islands somewhere in the Pacific Ocean during the Triassic time beginning around 245 million years ago. They were 600 to long and rode atop a microplate known as the Intermontane Plate. Over early Jurassic time the Intermontane Islands and the Pacific Northwest drew closer together as the continent moved west and the Intermontane Plate subducted. About 180 million years ago in the Mid-Jurassic time the last of the Intermontane Plate subducted and the Intermontane Islands collided with the Pacific Northwest, forming parts of British Columbia, Canada. The Intermontane