How long does it take for a swiftly moving stream to wear a rock down from being a rough broken rock to having a smooth surface. In other words for approx 1/4 of an inch of rock to be eroded away
2007-12-11 05:20:21 · 3 answers · asked by george 1 in Science & Mathematics ➔ Earth Sciences & Geology
It really depends on the velocity of the water and the type of rock you're talking about. Say you have limestone vs. granite. Limestone will erode much faster than granite. Stones will also be smoothed faster if it were found in a fast moving stream vs and placid lake. I know of large caves where the substrate was limestone that completely formed wihtin few thousand years. (this dissolving was because of the acidic nature of the water, however, not moving water). Rocks in fast moving streams can probably be smoothed out in a matter of years - water is more powerful than you may think! :)
2007-12-11 08:23:00 · answer #1 · answered by jlilly26 2 · 1⤊ 0⤋
Water actually make a rock rough, it's the other rocks that the water rubs against the rock in question that make it smooth or erode it. It also depends on how strong the stream/river is and how many months out of the year it has flowing water.
2007-12-11 05:29:33 · answer #2 · answered by So. Cal Man 3 · 0⤊ 2⤋
Hi. Usually a very long time, hundreds of thousands of years in my opinion. Most get rounded by having an ice sheet travel over them. This also takes a while, but makes for a shorter time, perhaps only hundreds of years.
2007-12-11 05:24:48 · answer #3 · answered by Cirric 7 · 0⤊ 1⤋