The Cathedral escarpment was a submarine cliff during the Cambrian period, and is often associated with the exquisite preservation of the Burgess Shale

Burgess Shale

The Burgess Shale Formation, located in the Canadian Rockies of British Columbia, is one of the world's most celebrated fossil fields, and the best of its kind. It is famous for the exceptional preservation of the soft parts of its fossils...

. It runs for around 100 km through and around Yoho national park

Yoho National Park

Yoho National Park is located in the Canadian Rocky Mountains along the western slope of the Continental Divide in southeastern British Columbia. Yoho NP is bordered by Kootenay National Park on the southern side and Banff National Park on the eastern side...

, British Columbia

British Columbia

British Columbia is the westernmost of Canada's provinces and is known for its natural beauty, as reflected in its Latin motto, Splendor sine occasu . Its name was chosen by Queen Victoria in 1858...

. During the Cambrian period mudflows ran down and along the escarpment, trapping and quickly burying organisms, and preventing their decay, permitting the preservation of soft tissue in the rocks that now comprise the Stephen formation

Stephen Formation

The Stephen Formation is a middle Cambrian unit exposed in the Canadian Rockies of British Columbia. It is famous for the exceptional preservation of soft-bodied fossils: the Burgess Shale biota...

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