hummocks left by the ice

[GeneD]

The shore is more flat on the Wayland side, and this town is the greatest loser by the flood. Its farmers tell me that thousands of acres are flooded now, since the dams have been erected, where they remember to have seen the white honeysuckle or clover growing once, and they could go dry with shoes only in summer. Now there is nothing but blue-joint and sedge and cut-grass there, standing in water all the year round. For a long time, they made the most of the driest season to get their hay, working sometimes till nine o'clock at night, sedulously paring with their scythes in the twilight round the hummocks left by the ice; but now it is not worth the getting, when they can come at it, and they look sadly round to their wood-lots and upland as a last resource (from "A week" by Thoreau).

Does anyone know what hummocks the author is talking about? Bog hummocks? Cryogenic earth hummocks? Else? Which hummocks are most likely to be in Massachusets in summer?

 

[GoesStation]

The author having specified "ice" tells us he was probably describing what we would now call cryogenic earth hummocks.