The Insular Belt is a physiogeological region on the north western North American coast. It consists of three major island groups and many smaller islands and stretches from southern

British Columbia British Columbia is the westernmost Provinces and territories of Canada, province of Canada. Situated in the Pacific Northwest between the Pacific Ocean and the Rocky Mountains, the province has a diverse geography, with rugged landscapes that ...

into

Alaska Alaska ( ) is a non-contiguous U.S. state on the northwest extremity of North America. Part of the Western United States region, it is one of the two non-contiguous U.S. states, alongside Hawaii. Alaska is also considered to be the north ...

and the

Yukon Yukon () is a Provinces and territories of Canada, territory of Canada, bordering British Columbia to the south, the Northwest Territories to the east, the Beaufort Sea to the north, and the U.S. state of Alaska to the west. It is Canada’s we ...

. It represents the

Late Cretaceous The Late Cretaceous (100.5–66 Ma) is the more recent of two epochs into which the Cretaceous Period is divided in the geologic time scale. Rock strata from this epoch form the Upper Cretaceous Series. The Cretaceous is named after ''cre ...

Eocene The Eocene ( ) is a geological epoch (geology), epoch that lasted from about 56 to 33.9 million years ago (Ma). It is the second epoch of the Paleogene Period (geology), Period in the modern Cenozoic Era (geology), Era. The name ''Eocene'' comes ...

accretion of what is known as the Insular Superterrane (formed from repeated accretion of multiple terranes) to the

North America North America is a continent in the Northern Hemisphere, Northern and Western Hemisphere, Western hemispheres. North America is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South Ameri ...

continent A continent is any of several large geographical regions. Continents are generally identified by convention (norm), convention rather than any strict criteria. A continent could be a single large landmass, a part of a very large landmass, as ...

. The rocks that form the Insular Superterrane are allochthonous, meaning they are not related to the rest of the North American continent. They consist of a series of volcanics, intrusions and

sedimentary rock Sedimentary rocks are types of rock (geology), rock formed by the cementation (geology), cementation of sediments—i.e. particles made of minerals (geological detritus) or organic matter (biological detritus)—that have been accumulated or de ...

s from the collision of an ancient

island arc Island arcs are long archipelago, chains of active volcanoes with intense earthquake, seismic activity found along convergent boundary, convergent plate tectonics, tectonic plate boundaries. Most island arcs originate on oceanic crust and have re ...

called the Insular Islands.The Coast Range Episode (115 to 57 million years ago)
/ref> The exact collision of the Insular Islands remains uncertain. The major island groups that compose the Insular Superterrane are, from south to north,

Vancouver Island Vancouver Island is an island in the northeastern Pacific Ocean and part of the Canadian province of British Columbia. The island is in length, in width at its widest point, and in total area, while are of land. The island is the largest ...

and the

Gulf Islands The Gulf Islands is a group of islands in the Salish Sea between Vancouver Island and the British Columbia Coast, mainland coast of British Columbia. Etymology The name "Gulf Islands" comes from "Gulf of Georgia", the original term used by Geor ...

, the

Haida Gwaii Haida Gwaii (; / , literally "Islands of the Haida people"), previously known as the Queen Charlotte Islands, is an archipelago located between off the British Columbia Coast, northern Pacific coast in the Canadian province of British Columbia ...

and the Alexander Archipelago in Alaska. The region is noteworthy as it has the greatest physiographic relief from the depths of Queen Charlotte Sound (which had been a coastal plain during the last ice age) to the heights of the Wrangell - Saint Elias Mountains. In general the region is extremely rugged with very little flat land except in certain regions (e.g. the east coast of Vancouver Island). The region is thickly forested, having a temperate year round climate, with many of the world's largest trees.

References

External links

Physiography of British Columbia
Geologic formations of Alaska Physiographic sections Volcanism of Alaska Volcanism of British Columbia Coast of British Columbia Belt regions of the United States {{Canada-geology-stub

See also

References

External links