Iapetus Ocean
The Iapetus Ocean was an ancient ocean that separated Laurentia, Baltica, and Avalonia before closing during the assembly of Pangaea.
Wilson cycle: The recurring opening and closing of ocean basins through plate tectonics. The Iapetus Ocean records a complete ocean-basin cycle, from rifting to continental collision.
Laurentia: An ancient continental landmass that formed the core of much of present-day North America. Laurentia formed one shore of the Iapetus Ocean.
Welsh Basin: A Paleozoic marine basin in what is now Wales, formed along the margin of the Iapetus Ocean. Its sedimentary rocks record marine conditions along the ocean’s southern margin.
Rheic Ocean: A Paleozoic ocean that separated Gondwana from Laurussia before closing during Pangaea’s assembly. It opened later and lay south of the Iapetus system, despite sharing a role in Pangaea’s assembly.
Laurussia: A Paleozoic continent formed from the collision of Laurentia, Baltica, and Avalonia. Its assembly marks the principal continental union that followed Iapetus closure.
Iapetus Suture: A geological boundary marking the former collision zone between continents once separated by the Iapetus Ocean. This suture preserves the ocean’s closure across parts of Britain and Ireland.
Baltica: An ancient continental landmass underlying much of northern and eastern Europe. Baltica lay across the ocean from Laurentia before their collision.
Southern Uplands: A fault-bounded belt of Paleozoic rocks in southern Scotland, assembled along the Iapetus margin. Its accreted sediments and structures preserve a record of ocean-margin processes.
Rodinia: A Neoproterozoic supercontinent that assembled before breaking apart during the late Precambrian. Rodinia’s breakup preceded the continental configurations from which Iapetus developed.
Caledonian Mountains: A mountain belt extending through parts of Scandinavia, Scotland, Ireland, and Greenland, formed during Caledonian orogeny. These mountains preserve the collision zone created as the ocean closed.