mining vs heading

mining and heading both are nouns.

Word	Noun	Adjective	Verb	Adverb
mining	Yes	No	No	No
heading	Yes	No	No	No

mining (noun)	heading (noun)
the act of extracting ores or coal etc from the earth	a horizontal (or nearly horizontal) passageway in a mine
laying explosive mines in concealed places to destroy enemy personnel and equipment	a line of text serving to indicate what the passage below it is about
	the direction or path along which something moves or along which it lies