The Chilliwack Batholith is a large batholith that forms much of the

North Cascades The North Cascades are a section of the Cascade Range of western North America. They span the border between the Canadian province of British Columbia and the U.S. state of Washington and are officially named in the U.S. and Canada as the Casca ...

in southwestern

British Columbia British Columbia (commonly abbreviated as BC) is the westernmost province of Canada, situated between the Pacific Ocean and the Rocky Mountains. It has a diverse geography, with rugged landscapes that include rocky coastlines, sandy beaches, ...

Canada Canada is a country in North America. Its ten provinces and three territories extend from the Atlantic Ocean to the Pacific Ocean and northward into the Arctic Ocean, covering over , making it the world's second-largest country by tot ...

and the

U.S. state In the United States, a state is a constituent political entity, of which there are 50. Bound together in a political union, each state holds governmental jurisdiction over a separate and defined geographic territory where it shares its sove ...

Washington Washington commonly refers to: * Washington (state), United States * Washington, D.C., the capital of the United States ** A metonym for the federal government of the United States ** Washington metropolitan area, the metropolitan area centered o ...

. The geological structure is named after the

Chilliwack River Chilliwack ( )( hur, Ts'elxwéyeqw) is a city in the province of British Columbia, Canada. Chilliwack is surrounded by mountains and home to recreational areas such as Cultus Lake and Chilliwack Lake Provincial Parks. There are numerous outdoo ...

Valley, where it outcrops in many places. It does not outcrop anywhere near the City of Chilliwack. The Chilliwack Batholith is part of the

Pemberton Volcanic Belt The Pemberton Volcanic Belt is an eroded Oligocene- Miocene volcanic belt at a low angle near the Mount Meager massif, British Columbia, Canada. The Garibaldi and Pemberton volcanic belts appear to merge into a single belt, although the Pembert ...

and is the largest mass of exposed intrusive rock in the

Cascade Volcanic Arc The Cascade Volcanoes (also known as the Cascade Volcanic Arc or the Cascade Arc) are a number of volcanoes in a volcanic arc in western North America, extending from southwestern British Columbia through Washington and Oregon to Northern Calif ...

. The age of the Chilliwack batholith ranges from 26 to 29 million years old.

References

Pemberton Volcanic Belt Igneous petrology of Washington (state) Batholiths of North America Igneous petrology of British Columbia Paleogene magmatism {{US-geology-stub