BackgroundMount Garibaldi's oldest known products are around half a million years old. Its first period of activity ended about 220,000 years ago and was followed by a period of quiescence. After this interval, a conical plug dome and breccia pile was formed at the south summit, Atwell Peak. Retreat of the ice cap at the end of the ice age left the west flank unsupported, and it collapsed in a series of landslides, exposing the core of the volcano. Lava flows from Dalton Dome north of Atwell Peak flowed down the scarp. Subglacial flank centers such as Eanastick (Enostuck) Meadow, Glacier Pike and Paul Ridge were also formed during the late Pleistocene.
The final activity of Mount Garibaldi formed the Opal Cone on the SE flank and the lengthy Ring Creek lava flow, which filled a glaciated valley on the south flank during the early Holocene.
Source: GVP volcano information
See also: Sentinel hub | Landsat 8