common fault vs normal fault

common fault and normal fault both are nouns.

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

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

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

Other synonyms of common fault include gravity fault.

common fault (noun)	normal 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