Superior Craton

The Superior Craton is an Archean block of ancient continental crust underlying much of central Canada and parts of the northern United States. Its exposed rocks preserve a record of volcanic arcs, sedimentary basins, and collisions that assembled the craton.

Canadian Shield: A vast area of exposed Precambrian igneous and metamorphic rocks surrounding Hudson Bay. The Superior Craton forms a major part of this larger shield region.
Greenstone belt: A sequence of metamorphosed volcanic and sedimentary rocks, commonly found in Archean terrains. Greenstone belts make up distinctive parts of several Superior terranes.
Timiskaming Basin: A set of late Archean sedimentary basins in the Abitibi region of Ontario and Quebec. Its sedimentary rocks record deformation and basin formation late in Abitibi’s history.
Plate tectonics in the Archean: The study of whether and how modern-style plate tectonics operated during the Archean eon. Superior rocks test competing models of Archean crust formation and movement.
Archean: The interval of geologic time from about 4.0 to 2.5 billion years ago. Most Superior Craton crust formed during this eon.
Island arc: A curved chain of volcanoes formed above a subducting oceanic plate. Arc volcanism produced rocks later incorporated into Superior crust.
Larder Lake–Cadillac Deformation Zone: A major Archean structural corridor crossing the Abitibi greenstone belt. The zone localizes deformation and many gold deposits within the craton.
Komatiite: A magnesium-rich volcanic rock formed from exceptionally hot, low-viscosity lava, especially common in the Archean. Komatiites in Superior greenstone belts constrain early mantle temperatures and melting.
Superior Province: A geologic province of Archean rocks in the Canadian Shield, commonly used for the exposed core of the Superior Craton. This name often designates the craton’s exposed Canadian core.
Subduction: The descent of one tectonic plate beneath another into the mantle. Subduction is one proposed setting for the craton’s volcanic arcs and crustal growth.

Linked from 5 pages