- Published: 02 February 2010
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Robert Pomfred, age 7, of Framingham, Mass., or his question;
A drumlin is not related to a goblin or a gremlin. It is related to a kame. The drumlin and the kame are both children of the glacier. Their cold, icy parent may be a valley glacier or a big flat ice field. Frozen within it are tons of rocks, gravel and sand. And the monster is always moving. Valley glaciers creep in tongues of ice downhill. Ice fields push outwards from the center. And with the slow moving ice goes all the rock and dirt frozen within it,
Sooner or later, this stuff is dumped. Ice melts at the glaciers edge, Rocks, toted maybe hundreds of miles, pile up into loose stuff called moraine. Muddy streams trickle out from behind the moraine. They carry tons of finer dirt and loose silt. And they cant wait to unload it.
Usually this dirt settles to form long rounded humps, Those little hills that run parallel to a valley are called drumlins. Those that cross the valley are called kames. The word drumlin is borrowed from an old Gaelic word drum, which means a hilltop.
The glaciers that crept down through the Ice Ages left piles of rocks and dirt behind them. Whenever an expert finds a drumlin, he knows that there a massive glacier was once stopped in its tracks.