Monte Garibaldi

Mount Garibaldi at the head of Howe Sound north of Vancouver is a Pleistocene dacitic stratovolcano capped by a lava dome complex. An initial period of volcanism 0.51-0.22 million years ago was followed after a period of quiescence by construction of a conical plug dome and breccia pile at the south summit, Atwell Peak. Retreat of the ice cap left the W 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 subsequently 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 formed the Opal Cone on the SE flank and the lengthy Ring Creek lava flow, which filled a glaciated valley on the S flank during the early Holocene (Mathews, 1958; Brooks and Friele, 1992).