Sentence:  Deposits of the Caribou Hills <WSD>glaciation</WSD> only locally retain a distinct hummocky morainal form, with filled kettle depressions and subdued knobs. Along the mountain fronts the marginal deposits of this <WSD>glaciation</WSD> reach an average altitude of slightly more than 3,000 feet. 
Meaning of the word marked with <WSD> tags:  A particular instance of glacier formation.