diggings vs excavation

diggings and excavation both are nouns.

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

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

diggings (noun)	excavation (noun)
temporary living quarters	the act of extracting ores or coal etc from the earth
an excavation for ore or precious stones or for archaeology	the act of digging
	a hole in the ground made by excavating
	the site of an archeological exploration