The Barrier/Garibaldi Lake

The Barrier/Garibaldi Lake

The Barrier was formed when two of the four lobes of a lava flow from Clinker Peak on Mt. Price met the retreating Cheakamus Valley Glacier of the last Pleistocene Cordilleran Ice Sheet and cooled in place. Garibaldi Lake then formed from glacial melt behind this ice-contact lava dam.

Visible where it looms over Hwy 99, The Barrier is considered unstable in the long term, and thus, a major geohazard—enough to have forced relocation of the small settlement of Garibaldi Village by the B.C. government in the early 1980s. This was deemed necessary because the fractured structure, constantly eroding via rock- and landslides, makes it a dam of dubious integrity holding back the ~trillion cubic metres of water in Garibaldi Lake. The lake’s only year-round outlet, Rubble Creek, erupts from springs far below The Barrier in a debris field of landslides that occurred in 1855-1856, and 1977, suggesting that water exiting the lake below ground could also be weakening the structure. Should The Barrier fail for any reason, the resulting outburst flood would be catastrophic to any downstream community.

The hike to Garibaldi Lake from which The Barrier is best viewed also provides access to Black Tusk and other volcanic features of Garibaldi Provincial Park.

  • imposing dacite lava-dam
  • Garibaldi Lake
  • collapse and continued landslide potential

GEOLOGIC CONTEXT:

A 250-metre-high, ice-contact dacite lava escarpment currently damming Garibaldi Lake; its potential instability makes for a significant geohazard.

HOW TO SEE IT:

Visible from Hwy 99 in the vicinity of Daisy Lake, The Barrier is best viewed from below, across and slightly above on the Rubble Creek/Garibaldi Lake trail.

Services:

Parking, washrooms at Rubble Creek trailhead.

Hazards:

Wilderness backcountry and sensitive ecosystems; stay on marked trails. High bear-use area: always carry bear spray in the backcountry.

Protection and guardianship are at the heart of the Geopark philosophy. We ask that you treat the land with the same reverence as its original inhabitants, and not remove anything from a site but what you’ve brought to help preserve it for future generations.

Decimal Degrees (DD)

49.957406, -123.120235

Degrees Decimal Minutes (DDM)

49° 57.4444' N   123° 7.2141' W

Degrees Minutes Seconds (DMS)

49° 57' 26.6616" N  123° 7' 12.846" W

What Are Pillars?

The Fire & Ice Aspiring Geopark comprises four main geological pillars referenced in all interpretive material: (M)ountain Building, (G)laciation, (V)olcanism and (C)ollapse.

MOUNTAIN BUILDING

Mountain building can involve several processes that contribute to the formation of mountains, such as the collision of tectonic plates that result in folding, faulting, metamorphism and the creation of subduction zones associated with volcanic activity and igneous intrusion.

GLACIATION

Glaciation refers to landform phenomena associated with the formation, movement and recession of glaciers and ice sheets. In temperate latitudes such as British Columbia, montane glaciation at higher altitudes is the norm while continental glaciation occurred during Ice Ages like the recent Pleistocene.

VOLCANISM

Volcanism is the eruption of subterranean molten rock (magma) and gasses onto the surface of the planet and includes the production of volcanic landforms and the effects of eruptions and flowing lava on pre-existing surface formations.

COLLAPSE

Collapse is a term that refers broadly to both slow processes of destabilization and erosion by wind, water and ice, as well as rapid processes like rockfall and landslides.

Whether acting as primary or secondary forces, one or more of these processes figure in the creation of each geosite.