Here's a bit more detail:

* Biogenic refers to anything derived from living organisms.

* Sedimentary rocks form from the accumulation and cementation of sediments, which can include fragments of other rocks, minerals, and organic material.

Examples of biogenic sedimentary rocks include:

* Coal: Formed from the accumulation and compaction of plant matter (mostly trees).

* Limestone: Often formed from the shells and skeletons of marine organisms like corals, mollusks, and foraminifera.

* Chalk: A type of limestone made primarily from the calcium carbonate shells of microscopic marine organisms called coccolithophores.

* Diatomite: Formed from the fossilized remains of diatoms, a type of single-celled algae.

These rocks are important sources of energy (coal), building materials (limestone), and even clues about past environments and life forms.