Saturday, June 5, 2010

Plinth Peak

Plinth Peak is the highest satellite cone of Mount Meager, and one of four overlapping volcanic cones which together form the northermost volcanic complex in the Cascade Volcanic Arc and the Garibaldi Volcanic Belt. Lying in the province of British Columbia, Canada, Plinth Peak is a stratovolcano, which last erupted about 2,350 years ago. Its oldest rocks date back to the Holocene, about 12,000 years ago. Plinth is 8,780 ft high and was first climbed in 1931 by a party who approached via horse from Pemberton.

Plinth Peak is the most recent volcanic peak of Mount Meager to erupt, and the source for the most recent explosive eruption in the Garibaldi Volcanic Belt. The eruption was similar to the 1980 eruption of Mount St. Helens, sending ash as far as Edmonton in southern Alberta and forming Keyhole Falls. The steep north face of the peak is the remnant of the inner crater wall, which was destroyed by the lateral blast of the eruption.