Definition of "morainal"

Below the glaciers throughout the entire Wind River Range great numbers of morainal lakes are found.

1895, J[ohn] W[esley] Powell, chapter III, in Canyons of the Colorado, Meadville, PA: Flood & Vincent; republished as The Exploration of the Colorado River and Its Canyons, New York: Dover, 1961, page 68

Grand Lake, probably the largest, is about three miles long by one mile wide. Its basin appears to be largely due to a morainal dam.

1915 April, Enos A. Mills, The Rocky Mountain Wonderland, Houghton Mifflin, page 157

The ice stopped at Perth Amboy, Metuchen, North Plainfield, Madison, Morristown—leaving a sinuous, morainal, lobate line that not only connects these New Jersey towns but keeps on going to the Rocky Mountains.

1983, John McPhee, In Suspect Terrain; reprinted in Annals of the Former World, New York: Farrar, Straus and Giroux, 1998, page 150