Silverthrone Caldera

Silverthrone Caldera
The approximate outline of the Silverthrone Caldera
Highest point
Elevation	3,160 m (10,370 ft)
Listing	List of volcanoes in Canada List of Cascade volcanoes
Coordinates	51°26′00″N 126°18′00″W / 51.43333°N 126.30000°W / 51.43333; -126.30000
Geography
Location	British Columbia, Canada
Parent range	Pacific Ranges
Geology
Age of rock	Holocene
Mountain type	Caldera complex
Volcanic arc/belt	Canadian Cascade Arc Pemberton/Garibaldi Belt
Last eruption	Unknown; possibly younger than 1000

The Silverthrone Caldera is a potentially activecaldera complex in southwestern British Columbia, Canada, located over 350 kilometres (220 mi) northwest of the city of Vancouver and about 50 kilometres (31 mi) west of Mount Waddington in the Pacific Ranges of the Coast Mountains. The caldera is one of the largest of the few calderas in western Canada, measuring about 30 kilometres (19 mi) long (north-south) and 20 kilometres (12 mi) wide (east-west).Mount Silverthrone, an eroded lava dome on the caldera's northern flank that is 2,864 metres (9,396 ft) high may be the highest volcano in Canada.

The main glaciers in the Silverthrone area are the Pashleth, Kingcome, Trudel, Klinaklini and Silverthrone glaciers. Most of the caldera lies in the Ha-Iltzuk Icefield, which is the largest icefield in the southern half of the Coast Mountains; it is one of the five icefields in southwestern British Columbia that thinned between the mid-1980s and 1999. Nearly half of the icefield is drained by the Klinaklini Glacier, which feeds the Klinaklini River.

The Silverthrone Caldera is very remote and rarely visited or studied by geoscientists, such as volcanologists. It can be reached by helicopter or — with major difficulty — by hiking along one of the several river valleys extending from the British Columbia Coast or from the Interior Plateau.

Silverthrone is part of the Pemberton Volcanic Belt, which is circumscribed by a group of epizonal intrusions. At another deeply eroded caldera complex called Franklin Glacier Volcano, the Pemberton Volcanic Belt merges with the Garibaldi Volcanic Belt, a northwest-trending belt of volcanic cones and fields extending from near the Canada–United States border east of Vancouver on the British Columbia Coast. The intrusions are thought to be subvolcanic bodies associated with a volcanic front that was active in the Miocene, during early stages of subduction of the Juan de Fuca Plate. With the notable exception of King Island, all the intrusive and eruptive rocks are calc-alkaline, mainly granodioritic bodies and dacite ejecta.