Cheakamus Basalt Eskers

Cheakamus Basalt Eskers

The Sea to Sky Trail links several geosites and viewscapes as it heads south from Whistler’s Cheakamus Crossing neighbourhood. This one-kilometre-long section is colloquially termed the “BC Rail Quarry” after the ballast was removed for an adjacent railway. In it are found both quarried and unquarried remnants of enigmatic basalt eskers—lava believed to have flowed and cooled beneath and beside a glacier in pre-existing meltwater channels, as evidenced by lava contact with glacio-fluvial sediments.

Formations include the preternaturally curved columnar jointing of Sugarcube Hill and an ice-contact wall overlooking the Cheakamaus River. The sinuous and surprisingly steep eskers create a pothole-studded topography that supports a unique, open-canopy forest of ancient Douglas-fir.

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.

  • hiking up and over a basalt esker
  • ancient and massive Douglas-fir trees
  • ice-contact lavas and Sugar Cube Hill

GEOLOGIC CONTEXT:

The quarried and unquarried remnants of various subglacial, subaerial and ice-bounded lava flows.

HOW TO SEE IT:

Located along the Sea to Sky Trail. From Hwy 99 northbound, 3 km north of Brandywine Falls Provincial Park, turn right and cross the train tracks onto Cal-Cheak FSR. From Whistler Village, the turnoff is located 14.3 km south, however, you must exit at the Callaghan Valley turnoff then return to the northbound highway to access Cal-Cheak FSR. Parking on the road across the road from the Cal Cheak B.C. Recreation Site, follow the Sea to Sky Trail north 1.5 km to the B.C. Rail Quarry. The Cheakamus River ice-contact overlook is on your right, Sugarcube Hill a further 50 metres on your left. Both formations are fragile and shouldn’t be touched; the loose rock is prone to dangerous rockfall. Alternate access: follow the Sea to Sky Trail south ~5 km from Whistler’s Cheakamus Crossing neighbourhood.

Services:

Road parking.

Hazards:

Sensitive ecosystem and extremely unstable rock areas; do not leave marked trail.

Decimal Degrees (DD)

50.071017, -123.092367

Degrees Decimal Minutes (DDM)

50° 4.2610' N  123° 5.5420' W

Degrees Minutes Seconds (DMS)

50° 4' 15.66" N  123° 5' 32.52" 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.