bioherm

The mountain range is considered a bioherm, an ancient barrier reef.

Dead Man's Point is a notable example of this, and is classified as a thrombolitic bioherm.

The water depth never exceeded 175-200 m, and shallowed over time as bioherm detritus, and terrestrial sediments, filled the basin.

As bioherm detritus and terrigenous infill accumulated, the coast prograded, and the reef zone advanced in front of it to the south west.

The earliest sponge-bearing reefs date to the Early Cambrian, (they are the earliest known reef structure built by animals), exemplified by a small bioherm constructed by archaeocyathids and calcified microbes at the start of the Tommotian stage about 540-535 million years ago (Mya), found in southeast Siberia.