excavation vs mineshaft

excavation and mineshaft both are nouns.

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

As nouns, mineshaft is a hyponym of excavation; that is, mineshaft is a word with a more specific, narrower meaning than excavation:

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

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