LINZ data def'n: "Moraine wall; an accumulation of boulders, stones or other debris, carried and deposited by the glacier to either side of the glacier, or at its terminal, forming a wall."
HB: see also the moraine poly layer: natural=landform; landform=moraine_wall ?? (I prefer Robin's suggestion above to that)
Glen wrote on the ML 7 Sept 2012: natural=landform + landform=moraine_wall Would be my take as well.
HB 9 Sept 2012: approved for the mainland.