2007-10-02 12:01:00 · 3 answers · asked by Kevin_Mart13 3 in Science & Mathematics ➔ Earth Sciences & Geology
They did a lot of it.
The retreating and advancing glaciers of the various ice ages ran across the ground and ground down a lot of those rocks, as well as moving them further south. This was first noticed in New York some of the large boulders there once came from Canada and were carried south by the glacier action.
Glaciers act like bulldozers pushing the ground in front or them, or running over the ground they are on top of. Then when the glaciers melt and retreat the extra water added to the erosion.
2007-10-02 12:18:19 · answer #1 · answered by Dan S 7 · 0⤊ 0⤋
When glaciers are on the move they grind up huge amounts of solid rock!
2007-10-02 19:05:38 · answer #2 · answered by Anonymous · 0⤊ 0⤋
ice is very hard so it can grind the rocks beneath it or push bigger rocks foward
2007-10-02 19:40:24 · answer #3 · answered by filldwth? 3 · 0⤊ 0⤋