| − | '''Argillaceous''' means rich in clay, and is most often applied to rocks.<ref>http://wrgis.wr.usgs.gov/docs/parks/misc/glossaryAtoC.html</ref> | + | '''Argillaceous''' is a word to describe [[rock]]s which are rich in [[clay]]. <ref>http://wrgis.wr.usgs.gov/docs/parks/misc/glossaryAtoC.html</ref> |