Fig. 337.—Map of the vicinity of Devils Lake, Wisconsin, located within a reëntrant of the “kettle” moraine upon the margin of the Driftless Area. The lake lies within an earlier channel of the Wisconsin River which has been blocked at both ends, first by the glacier and later by its moraine. The stippled area upon the heights and next the moraine represents the clay deposits of a former lake (based on map by Salisbury and Atwood).
Fig. 338.—Moraine with outwash apron in front, the latter in part eroded by a river. Westergötland, Sweden (after H. Munthe).
Fig. 339.—Fosse between an outwash plain (in the foreground) and the moraine, which rises to the left in the middle distance. Ann Arbor, Michigan.
Kames.—Within reëntrants or recesses of the ice margin the drift deposits were especially heavy, so that high hills of hummocky surface have been built up, which are described as kames. Most of the higher drift hills have this origin. They rarely have any principal extension along a single direction, but are composed in large part of assorted materials. In contrast with other portions of the morainal ridges they lack the prominent basins known as kettles. Other kames are high hills of assorted materials not in direct association with moraines and believed to have been built up beneath glacier wells or mills ([p. 278]).
Outwash plains.—Upon the outer margin of the moraine is generally to be found a plain of glacial “outwash” composed of sand or gravel deposited by the braided streams ([Fig. 308], [p. 280]) flowing from the glacier margin. Such plains, while notably flat ([Fig. 338]), slope gently away from the moraine. Between the outwash plain and the moraine there is sometimes found a pit, or fosse ([Fig. 309], [p. 281]), where a part of the ice front was in part buried in its own outwash ([Fig. 339]).