geology vs clastic

geology is a noun but clastic is not a noun.

Word	Noun	Adjective	Verb	Adverb
geology	Yes	No	No	No
clastic	No	Yes	No	No

geology (noun)	clastic (noun)
a science that deals with the history of the earth as recorded in rocks

geology (adjective)	clastic (adjective)
	capable of being taken apart
	of or belonging to or being a rock composed of fragments of older rocks (e.g., conglomerates or sandstone)