Changes

[[Image:Biological Sedimentary Rock.jpg|thumb|300px]]'''Biologic sedimentary rocks''' form when large numbers of living things die, pile up, and are compressed and cemented to form rock. Accumulated carbon-rich plant material may form coal. Deposits made mostly of animal shells may form limestone, coquina, or chert.<ref>http://wrgis.wr.usgs.gov/docs/parks/rxmin/rock2.html</ref>

[[Image:Biological Sedimentary Rock.jpg|thumb|300px]]'''Biologic sedimentary rocks''' form when large numbers of living things die, pile up, and are compressed and cemented to form [[rock]]. Accumulated carbon-rich plant material may form coal. Deposits made mostly of animal shells may form limestone, coquina, or chert.<ref>http://wrgis.wr.usgs.gov/docs/parks/rxmin/rock2.html</ref>

==References==

==References==