Wyoming Craton

The Wyoming Craton, also called the Wyoming Province, is a craton in the west-central United States and western Canada, covering parts of Montana, Wyoming, southern Alberta, southern Saskatchewan and northern Utah, and it represents the initial core of the continental crust of North America. It originated as a middle Archean craton, with gneisses dated between 3.6 and 3.0 billion years old, later modified by late Archean volcanism and by Proterozoic extension and rifting, and it consists mainly of granitoid plutons dated between 2.8 and 2.55 billion years old together with gneiss and migmatite, with a smaller share of metavolcanic and metasedimentary rock. It was incorporated into southwestern Laurentia about 1.86 billion years ago through a suturing of the Wyoming, Superior and Hearne-Rae cratons that formed the Trans-Hudson Suture Zone.