prehistoric culture vs glacial period

prehistoric culture and glacial period both are nouns.

Word	Noun	Adjective	Verb	Adverb
prehistoric culture	Yes	No	No	No
glacial period	Yes	No	No	No

prehistoric culture (noun)	glacial period (noun)
the time during the development of human culture before the appearance of the written word	any period of time during which glaciers covered a large part of the earth's surface