workings vs excavation

workings and excavation both are nouns.

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

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

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