Stephen Formation

Stephen Formation is a geological layer made of shale mixed with limestone and siltstone spanning across the Canadian Rockies in British Columbia and Alberta. The deposits vary in thickness and composition depending on whether they formed in shallow waters or in deeper areas beyond the Cathedral escarpment.

This formation developed during the Middle Cambrian period, roughly 513 to 497 million years ago, when sediments accumulated in ancient marine settings. That era marked a time when ocean life was expanding and diversifying rapidly.

Scientists study this formation extensively for its remarkably preserved soft-bodied fossils, which form the Burgess Shale collection at multiple quarry sites.

The formation can be viewed at several quarry sites and outcrops along mountain routes in the region, particularly during warmer months. Plan visits when access roads are clear and conditions allow for safe exploration of these geological exposures.

The sediments contain dark mudstone layers approximately 508 million years old, preserved at depths of 200 meters beneath ancient storm wave zones.

Location: British Columbia

Made from material: shale

GPS coordinates: 51.46420,-116.32400

Latest update: December 13, 2025 11:47