bank gravel vs pit run

bank gravel and pit run both are nouns.

Word	Noun	Adjective	Verb	Adverb
bank gravel	Yes	No	No	No
pit run	Yes	No	No	No

As nouns, bank gravel and pit run are synonyms defined as:

Other synonyms of bank gravel include pit-run gravel.

bank gravel (noun)	pit run (noun)
gravel as found in natural deposits	gravel as found in natural deposits