Trans-Hudson Orogen

The Trans-Hudson orogen is a Paleoproterozoic mountain-building belt, dated to about 2.0 to 1.8 billion years ago, that runs from Saskatchewan east through the Churchill Province, Quebec, Labrador and Baffin Island to Greenland, and south through Montana, the Dakotas, Wyoming and Nebraska. It formed as the Superior Craton collided with the Hearne and Wyoming cratons, trapping the smaller Sask Craton between them, in a process of oceanic subduction, volcanic arc building and extensive folding, thrust faulting and metamorphism accompanied by hundreds of large granitic intrusions. Considered the largest Paleoproterozoic orogenic belt known anywhere in the world, it welded together the cratons and microcontinents that became the cratonic core of North America, and today only the worn-down roots of its mountains remain visible, most notably in South Dakota's Black Hills. This entity documents the Trans-Hudson orogen specifically as a geological formation, distinct from Hudson Bay, the body of water it is named for.