What conditions created the numerous fossils that make up the Burgess Shale?

The Burgess Shale is a rock formation that is known for having an abundance of soft bodied organisms preserved in shale. This formation is significant because it preserves organisms from the Cambrian Explosion. The Cambrian Explosion is a period in time that coincides with the Pre - Cambrian - Cambrian boundary around 542 million years ago. The period represents an unusually rapid radiation of organisms.

Fossils of the Burgess Shale are thought to be well preserved because most were thought to be buried fairly rapidly and in conditions that had little or no oxygen. The rate of decomposition is slowed in these conditions so soft body parts of the organisms were preserved for millions of years in the mud-stone that eventually became lithified to shale.