Variscan orogeny rifted off the north Gondwana margin in early Ordovician. By the end of the Silurian and in Early Devonian times, Baltica and Laurentia drifted towards each other, closing the Iapetus Ocean between them. They collided in the Caledonian orogeny and formed the Caledonide mountains of North America, Greenland, the British Isles and Norway. Seafloor spreading to the south of Avalonia pushed the latter into north Laurentia and thrust up the northern Appalachian Mountains in the acadian phase of the Caledonian orogeny. Contemporaneously the Tornquist Sea between Avalonia and Baltica was entirely closed. Thus Avalonia formed the southern coast of the
Brasiliano orogeny and the Peri-Franciscano Ocean. Attempts to correlate the South American Brasiliano belts with the African Pan-African belts on the other side of the Atlantic has in many cases been problematic. Brasiliano orogeny Brasiliano orogeny or Brasiliano cycle ( and "Ciclo Brasiliano") refers to a series of orogenies of Neoproterozoic age exposed chiefly in Brazil but also in other parts of South America. The Brasiliano orogeny is a regional name for the larger Pan-African/Brasiliano orogeny that extended not only in South America but across most of Gondwana. In a wide sense the Brasiliano orogeny includes also the Pampean orogeny. Almeida "et