The mountain is composed of Shuksan greenschist, oceanic basalt that was metamorphosed when the Easton terrane collided with the west coast of North America, approximately 120 million years ago. The mountain is an eroded remnant of a thrust plate formed by the Easton collision.

citation

Wikipedia contributors. (2023, March 5). Mount Shuksan. In Wikipedia, The Free Encyclopedia. Retrieved January 4, 2024, from https://en.wikipedia.org/w/index.php?title=Mount_Shuksan&oldid=1143099746

Mount Shuksan (Wikipedia) Mount Shuksan is a glaciated massif in the North Cascades National Park. Shuksan rises in Whatcom County, Washington immediately to the east of Mount Baker, and 11.6 miles (18.7 km) south of the Canada–US border. The mountain’s name Shuksan is derived from the Lummi word [šéqsən], said to mean “high peak”. The highest point on the mountain is a three-sided peak known as Summit Pyramid.