Evidently, the land here was giving way, little by little, for here and there they could see a tree canting tipsily over the edge, its network of half-exposed roots making a last gallant stand against the erosive process and helping to hold the weight of the great boulders which ere long would crash down into the marshy lowlands.
"Tom Slade with the Boys Over There"
Percy K. Fitzhugh
It is impossible to deny that the mere geographical distribution of lakes points to the intimate connection of their origin with the abundance of ice during a former excess of cold, but how far the erosive action of moving ice has been the sole or even the principal cause of lake-basins, is a question still open to discussion.
"The Student's Elements of Geology"
Sir Charles Lyell
This erosive action is due to the gravel, sand, and mud carried along by the water.
"Geology"
James Geikie