excavation vs workings

excavation and workings both are nouns.

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

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

excavation (noun)	workings (noun)
the act of extracting ores or coal etc from the earth	the internal mechanism of a device
the act of digging	a mine or quarry that is being or has been worked
a hole in the ground made by excavating
the site of an archeological exploration