Laurasia

Laurasia
Laurasia (centre) and Gondwana (bottom) as part of Pangaea 200 Mya (Early Jurassic)
Historical continent
Formed1,071 Mya (Proto-Laurasia) 253 Mya
TypeSupercontinent
Today part of
Smaller continents
Tectonic plates

Laurasia (/lɔːˈrʒə, -ʃiə/)[1] was the more northern of two large landmasses that formed part of the Pangaea supercontinent from around 335 to 175 million years ago (Mya), the other being Gondwana. It separated from Gondwana 215 to 175 Mya (beginning in the late Triassic period) during the breakup of Pangaea, drifting farther north after the split and finally broke apart with the opening of the North Atlantic Ocean c. 56 Mya. The name is a portmanteau of Laurentia and Asia.[2]

Laurentia, Avalonia, Baltica, and a series of smaller terranes, collided in the Caledonian orogeny c. 400 Ma to form Laurussia/Euramerica. Laurussia/Euramerica then collided with Gondwana to form Pangaea. Kazakhstania and Siberia were then added to Pangaea 290–300 Ma to form Laurasia. Laurasia finally became an independent continental mass when Pangaea broke up into Gondwana and Laurasia.[3]

  1. ^ Oxford English Dictionary
  2. ^ Du Toit 1937, p. 40
  3. ^ Torsvik & Cocks 2004, Laurussia and Laurasia, pp. 558, 560