Patagonia Glaciers And The Southern Andes

Just imagine the effect of an immense mass of ice sliding down the mountainside. The pressure that it exerts on the slopes is enormous and a large quantity of rock is ripped loose and dragged with it. And if there is anything solid or heavy enough to resist the onslaught, it must withstand the crushing weight of this tide of ice and stone. The rocks trapped in the base of the glacier act like chisels, leaving imprinted in even the hardest substrata, a series of scars that are visible a million years later.