mineshaft vs excavation

mineshaft and excavation both are nouns.

Word	Noun	Adjective	Verb	Adverb
mineshaft	Yes	No	No	No
excavation	Yes	No	No	No

As nouns, excavation is a hypernym of mineshaft; that is, excavation is a word with a broader meaning than mineshaft:

mineshaft: excavation consisting of a vertical or sloping passageway for finding or mining ore or for ventilating a mine
excavation: a hole in the ground made by excavating

mineshaft (noun)	excavation (noun)
excavation consisting of a vertical or sloping passageway for finding or mining ore or for ventilating a mine	the act of extracting ores or coal etc from the earth
	the act of digging
	a hole in the ground made by excavating
	the site of an archeological exploration