The alpine meadows, glaciers, and striking blue lakes of Garibaldi Provincial Park are set in a volcanic landscape of lava flows and cinder cone volcanoes. These landforms record the interaction of volcanic eruptions with glacial ice. The most recent volcanic activity occurred during the last Ice Age that ended 10,000 years ago.

The Eroded Volcano

Mt. Garibaldi, an eroded volcano, towers two and a half kilometers above downtown Squamish.

Mt. Garibaldi was built by violent volcanic eruptions 15 to 20 thousand years ago when the Squamish Valley was filled with a large glacier. Volcanic debris that formed the western flank of the volcano spread across the surface of the glacier. When the glacier later melted, the western side of the volcano collapsed into the Squamish Valley.

When Lava Intrudes a Glacier

The unusual flat top of the Table is due to the eruption of lava into a stagnant glacier that once covered the Garibaldi area. Erupted from below, the hot lava melted a hole in the base of the glacier forming a pool of lava surrounded by ice. Later when the glacier melted, the lava remained as a rock column with its flat top.

Garibaldi Lake: Dammed by Lava

Garibaldi Lake owes its origin to lava that flowed into an ancient river valley, damming stream waters and forming the lake. Glacier melt waters that flow into the lake are rich in finely ground rock particles (rock flour) that scatter sunlight and give the lake its striking milky blue colour.

Black Tusk: Volcanic Roots

Black Tusk, a spire of volcanic rock over two hundred metres high, is interpreted as the remnant of a small volcano, perhaps the conduit for lava within a cinder-rich volcano. The loose cinder has eroded, leaving only the hard lava core.

Layers Record Violent Eruptions

Layers of ancient volcanic blocks and ash have been exposed by the erosion of Mt. Garibaldi volcano in the upper Cheekye valley. The layers were deposited by hot avalanches of volcanic debris sweeping down the flanks of the volcano during explosive eruptions.

Through the Microscope

Garibaldi lava is composed of pinkish matrix (m) and crystals of the minerals feldspar (f) and amphibole (a). The matrix consists of submicroscopic crystals formed by rapid cooling of lava to rock during eruption. The large feldspar and amphibole crystals started forming deep in the Earth and were carried to surface with the rising magma.