Laurentia

Laurentia is a large continental craton. It forms the ancient geological core of the North American continent.

Originally, it included the core of Greenland and the northwestern part of Scotland, known as the Hebridean Terrane. Laurentia is also called the North American Craton. It is a modern geological feature, and it is also a very ancient geological core made of igneous rock. It is nearly four billion years old.

At times in the past, Laurentia has been part of larger continents and supercontinents. It is an assembly of smaller tectonic plates which merged early in the Archaean era. As the plates moved together, a huge range of mountains formed. Much later, in the Proterozoic era, small plates and oceanic islands collided with and fused with the ever-growing Laurentia. Together they made the huge, stable craton we see today as the north and center of North America and the west of Greenland.^[1]

Over a billion years ago, the Grenville Orogeny in the Canadian Shield made jagged peaks, higher than any of today's mountains. Millions of years of erosion have changed these mountains to rolling hills.^[2]

The remaining, western, part of North America was added much later, after Pangaea split up, and the Americas moved west from Eurasia and Gondwana.

The craton is named after the Laurentian Mountains, a range to the north of the St. Lawrence River.

1. ↑ Dalziel I.W.D. 1992. "On the organization of American plates in the Neoproterozoic and the breakout of Laurentia". GSA Today. 2 (11): 237–241.{{cite journal}}: CS1 maint: numeric names: authors list (link)
2. ↑ James-Abra, Erin. "Canadian Shield". Canadian Encyclopedia. Retrieved 24 January 2018.