biostrome
/ˈbaɪoʊˌstroʊm/
noun
- A layered, sheet-like rock formation made mostly from the remains of marine organisms, such as shells or coral.
- Geologists studied the biostrome to understand the prehistoric ocean environment.
- The cliff face revealed a thick biostrome formed from ancient oyster shells.
- Fossil hunters found many well-preserved clams in the limestone biostrome.