Laurussia in the context of "Caledonian orogeny"

The Variscan orogeny or Hercynian orogeny was a geologic mountain-building event caused by Late Paleozoic continental collision between Euramerica (Laurussia) and Gondwana to form the supercontinent of Pangaea. It remains visible today as a series of isolated massifs, including the Ardennes, Bohemian Massif, Vosges-Black Forest, Armorican Massif, Cornubian Massif, Massif Central, and Iberian System. These are interspersed with Mesozoic and Cenozoic sedimentary basins. The chain also crops out in southern Ireland and was later incorporated into the Alpine orogeny (external crystalline massifs) and Pyrenean orogeny. These ancient massifs form the pre-Permian basement of western and Central Europe, part of a larger mountain system stretching from the Ural Mountains in Russia to the Appalachian Mountains in North America.

The chain originated from the convergence and collision of three continental masses: the microcontinent Armorica and the supercontinents Protogondwana and Laurussia (a union of Laurentia and Baltica from the Caledonian orogeny). This convergence contributed to the formation of the supercontinent Pangaea.

A paleocontinent or palaeocontinent is a distinct area of continental crust that existed as a major landmass in the geological past. There have been many different landmasses throughout Earth's time. They range in sizes; some are just a collection of small microcontinents while others are large conglomerates of crust. As time progresses and sea levels rise and fall more crust can be exposed making way for larger landmasses. The continents of the past shaped the evolution of organisms on Earth and contributed to the climate of the globe as well. As landmasses break apart, species are separated and those that were once the same now have evolved to their new climate. The constant movement of these landmasses greatly determines the distribution of organisms on Earth's surface. This is evident with how similar fossils are found on completely separate continents. Also, as continents move, mountain building events (orogenies) occur, causing a shift in the global climate as new rock is exposed and then there is more exposed rock at higher elevations. This causes glacial ice expansion and an overall cooler global climate. The movement of the continents greatly affects the overall dispersal of organisms throughout the world and the trend in climate throughout Earth's history. Examples include Laurentia, Baltica and Avalonia, which collided together during the Caledonian orogeny to form the Old Red Sandstone paleocontinent of Laurussia. Another example includes a collision that occurred during the late Pennsylvanian and early Permian time when there was a collision between the two continents of Tarimsky and Kirghiz-Kazakh. This collision was caused because of their askew convergence when the paleoceanic basin closed.