Trans-Hudson orogeny

Trans-Hudson orogen (blue) surrounded by the Wyoming Hearne-Rae and Superior cratons (fuchsia) that constitute the central core of the North American Craton (Laurentia).
Trans-Hudson orogen and the Wyoming, Superior and Hearne cratons

The Trans-Hudson orogeny or Trans-Hudsonian orogeny was the major mountain building event (orogeny) that formed the Precambrian Canadian Shield and the North American Craton (also called Laurentia), forging the initial North American continent. It gave rise to the Trans-Hudson orogen (THO), or Trans-Hudson Orogen Transect (THOT), (also referred to as the Trans-Hudsonian Suture Zone (THSZ) or Trans-Hudson suture) which is the largest Paleoproterozoic orogenic belt in the world. It consists of a network of belts that were formed by Proterozoic crustal accretion and the collision of pre-existing Archean continents. The event occurred 2.0–1.8 billion years ago.

The Trans-Hudson orogen sutured together the Hearne-Rae, Superior, and Wyoming cratons to form the cratonic core of North America in a network of Paleoproterozoic orogenic belts. These orogenic belts include the margins of at least nine independent microcontinents that were themselves sections of at least three former major supercontinents, including Laurasia, Pangaea and Kenorland (ca. 2.7 Ga), and contain parts of some of the oldest cratonic continental crust on Earth. These old cratonic blocks, along with accreted island arc terranes and intraoceanic deposits from earlier Proterozoic and Mesozoic oceans and seaways, were sutured together in the Trans-Hudson Orogen (THO) and resulted in extensive folding and thrust faulting along with metamorphism and hundreds of huge granitic intrusions.[1]

The THO is a right-angled suture zone that extends eastward from Saskatchewan through collisional belts in the Churchill province, through northern Quebec, parts of Labrador and Baffin Island, and all the way to Greenland as the Rinkian belt and Nagssugtodidian Orogen. Westward it goes across Hudson Bay through Saskatchewan and then extends 90 degrees south through eastern Montana and the western Dakotas, downward through eastern Wyoming and western Nebraska, and is then cut off by the Cheyenne belt - the northern edge of the Yavapai province (see Trans-Hudson Orogen map[2] and the THOT Transect map.[3] To the south, the orogen contributed to the subsurface Phanerozoic strata in Montana and the Dakotas that created the Great Plains.

  1. ^ M. Stauffer (2006). "Trans-Hudson Orogen". The Encyclopedia of Saskatchwen. Archived from the original on 2017-06-27. Retrieved 2008-01-27. Retrieved on 2008-02-11
  2. ^ Canadian Plains Research Center Mapping Division (2006). "Location of the Trans-Hudson Orogen" (PDF). Canadian Plains Research Center Mapping Division. {{cite journal}}: Cite journal requires |journal= (help) Retrieved on 2008-02-11
  3. ^ Canada's National LITHOPROBE Geoscience Project (1998). "Transects". Canada's National LITHOPROBE Geoscience Project. Archived from the original on 2012-07-18. Retrieved 2012-07-18. {{cite journal}}: Cite journal requires |journal= (help)