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Tectonic elements of North America, with the sedimentary cover removed.

It looks a bit different from other maps in that the Baltic Shield is shown where it once had been, and Greenland is restored to where it had been before it rifted away from North America. And it shows more detail than the earlier map of tectonic elements. The yellow boxes outline LITHOPROBE’s 10 study areas (or transects): SC, Southern Cordillera; SNORCLE, Slave-Northern Cordillera Lithospheric Evolution; AB, Alberta Basement; THOT, Trans-Hudson Orogen Transect; WS, Western Superior; KSZ, Kapuskasing Structural Zone; GL, Great Lakes International Multidisciplinary Program on Crustal Evolution; AG, Abitibi-Grenville; LE, Lithoprobe East; and ECSOOT, Eastern Canadian Shield Onshore-Offshore Transect.

Archean Cratons
We already heard that the Archean protocraton is an aggregate of six former microcontinents, named "provinces" (e.g. Superior Province). Each of the six provinces is a Late Archean, crustal aggregate containing variable proportions of Early and/or Middle Archean crust; they each have an internal, evolutionary history. Look for the red and purple colours on the slide.
This Archean protocraton has been named Laurentia. It contains the Slave, Nain, Superior, Wyoming, Hearne and Rae provinces, all former microcontinents.

The oldest known rocks on Earth, about 4,000,000,000 years old (that’s 4,000 million years old or 4,000 Ma), occur in the western part of the Slave Province.

Although each of the six Archean provinces had a different history, they all have had major crustal growth between 2,800 and 2,600 Ma. New lithosphere formed from underlying, partially molten rocks.

During the Early Proterozoic, rifting occurred in these oldest provinces. Subsequently, these Archean microcontinents were welded together by enormous and lengthy collisions which raised mighty mountain belts (orogens) between them, primarily from 2,000 to 1,800 Ma. The continent of North America began to take shape.

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