normal fault vs common fault

normal fault and common fault both are nouns.

Word	Noun	Adjective	Verb	Adverb
normal fault	Yes	No	No	No
common fault	Yes	No	No	No

As nouns, normal fault and common fault are synonyms defined as:

normal fault and common fault: an inclined fault in which the hanging wall appears to have slipped downward relative to the footwall

Other synonyms of normal fault include gravity fault.

normal fault (noun)	common fault (noun)
an inclined fault in which the hanging wall appears to have slipped downward relative to the footwall	an inclined fault in which the hanging wall appears to have slipped downward relative to the footwall