Sandstone Cliff Erosion on De Courcy Island, British Columbia

August 12, 2019

Sandstone erosion 2

Photographer: Glenn McCreery 
Summary Author: Glenn McCreery 

Sandstone cliffs on several of the Gulf Islands in British Columbia display complicated erosion features, including elaborate honeycomb patterns, as shown above. These two photographs were taken while sea kayaking along the southwest facing shore of De Courcy Island, located approximately 16 km (9.9 mi) southeast of Nanaimo, British Columbia.

The honeycomb structure is thought to be the result of rainwater percolating through the porous sandstone and then evaporating at the surface. Surface erosion occurs due to salt, acquired within the sandstone, attacking the clay that cements the particles of sand together. The honeycombing is mostly observed on south or southwest facing cliffs because evaporation is most active here during the spring and summer months. Photos taken on July 21, 2019.

Photo Details: Camera: Olympus TG4 Tough; f/8.0; ISO 200;1/80 sec. exposure; 25mm (35mm equivalent). Second photo - same except: f/9.0; 1/30 sec. exposure; 28mm (35mm equivalent).