The Coast Range Arc was home to some of the world's most dangerous and explosive volcanoes. Cataclysmic eruptions at the British Columbia-Yukon border created a huge nested caldera called the Bennett Lake Volcanic Complex about 50 million years ago during the early Eocene period. These eruptions were from vents along arcuate fracture systems associated with the caldera, which discharged about of pyroclastic material. This volcanic event occurred shortly before nearly all the Kula Plate had been subducted beneath the North American Plate about 40 million years ago.