Paleomagnetic data from the Grenville Province of North America suggest that Laurentia underwent ∼4000 ± 1000 km of crustal shortening from ca. 1040–1020 Ma to 980 Ma as a result of the Grenville orogeny, in which Laurentia was in collision with Amazonia. A corollary is that the size and scale of shortening affect the assembly of continental fragments that include Laurentia, which before 1 Ga may have been significantly larger in area than now by thousands of square kilometers, caused by crustal shortening in a broadly northwest-southeast direction by the Grenville orogeny.

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