perusing vs poring over

perusing and poring over both are nouns.

Word	Noun	Adjective	Verb	Adverb
perusing	Yes	No	No	No
poring over	Yes	No	No	No

As nouns, perusing and poring over are synonyms defined as:

Other synonyms of perusing include perusal, studying.

perusing (noun)	poring over (noun)
reading carefully with intent to remember	reading carefully with intent to remember