Craton

A craton (/ˈkreɪtɒn/, /ˈkrætɒn/, or /ˈkreɪtən/; from Greek: κράτος kratos "strength") is an old and stable part of the continental lithosphere. Having often survived cycles of merging and rifting of continents, cratons are generally found in the interiors of tectonic plates. They are characteristically composed of ancient crystalline basement rock, which may be covered by younger sedimentary rock. They have a thick crust and deep lithospheric roots that extend as much as several hundred kilometres into the Earth's mantle.

The term craton is used to distinguish the stable portion of the continental crust from regions that are more geologically active and unstable. Cratons can be described as shields, in which the basement rock crops out at the surface, and platforms, in which the basement is overlaid by sediments and sedimentary rock.

The word craton was first proposed by the Austrian geologist Leopold Kober in 1921 as Kratogen, referring to stable continental platforms, and orogen as a term for mountain or orogenic belts. Later authors shortened the former term to kraton and then to craton.

Superior Craton

The Superior Craton or Superior Province is an Archean craton which forms the core of the Canadian Shield lying north of Lake Superior for which it is named.

The craton extends from northwestern Quebec along the east side of Hudson Bay south through Ontario to the north shores of Lake Huron and Lake Superior. It extends across western Ontario south of Hudson Bay and underlies most of southeastern Manitoba. It extends southward through eastern North and South Dakota and western Minnesota.

It is bounded on the west and north by the Proterozoic Trans-Hudson orogen which separates it from the Wyoming, Hearne, Slave, Rae and Nain cratons. On the southeast it is bounded by the Grenville Front and to the south by the Midcontinent Rift System and the Yavapai – Mazatzal terranes.

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