Laurentia

Laurentia is an ancient continental craton forming the stable core of North America. Its exposed rocks include much of the Canadian Shield and parts of the United States.

Craton: An old, stable part of continental lithosphere that has resisted major deformation for billions of years. Laurentia is one of the largest and best-preserved examples of this continental structure.
Archean: A geological eon lasting from about 4.0 to 2.5 billion years ago, when Earth’s earliest stable continental crust developed. Some of Laurentia’s oldest surviving rocks originated during this eon.
Continental rifting: The stretching and thinning of continental lithosphere that can split a continent and initiate an ocean basin. Rifting repeatedly opened new margins around Laurentia, including during Rodinia’s breakup.
Appalachian Mountains: A mountain range in eastern North America formed through Paleozoic continental collisions and later erosion. The range preserves the consequences of collisions along Laurentia’s eastern edge.
Canadian Shield: A broad region of exposed Precambrian crystalline rock across Canada. It exposes much of Laurentia’s ancient basement at the surface.
Superior Craton: A large Archean craton underlying parts of central Canada and the northern United States. It is one of the major ancient blocks at Laurentia’s core.
Seafloor spreading: The creation of oceanic crust as magma rises at a divergent plate boundary and solidifies. It widened oceans that separated Laurentia from neighboring continents.
Interior Platform: A region of relatively undeformed sedimentary rocks covering parts of the ancient North American craton. Its broad strata overlie Laurentia’s stable basement away from major mountain belts.
Canadian Shield provinces: Geological regions of the Canadian Shield distinguished by their rock ages and geological histories. Their boundaries reveal the distinct crustal blocks assembled into Laurentia.
Trans-Hudson orogen: A Paleoproterozoic mountain belt formed by collision of Archean continental blocks in central North America. Its collision welded major fragments into a more coherent Laurentian continent.

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