Young-earth "proof" #15: Continents are eroding at a rate which would bring them to sea level in less than 14 million years. Inasmuch as the continents are anything but flat, the earth cannot be billions of years old. (27.5 x 10^9 tons sediment/year are lost to the oceans by erosion; the present mass of the continents above sea level is 383 x 10^15 tons.)
15. This argument, advanced by creationist Stuart E. Nevins in the ICR Impact series (No.8) in 1973, simply ignores the impact of modern geology! Nevins overlooks the fact that the continents are dynamic and have grown appreciably over time, both by accretion of material at the margins and by addition of material from the mantle below (Dalrymple, 1984, p.114). Volcanic activity, the emplacement of gigantic masses of rising, molten rock, and the stupendous compressional forces of the earth’s colliding plates have been building mountains off and on for billions of years. Mountain building is going on even now in many parts of the world.
I could also mention that the current rates of erosion are particularly high and that isostatic rebound would greatly increase the time for a continent to erode flat, but that’s just icing on the cake. Any argument which pretends that continents are inert lumps of rock subject only to erosion is out of touch with reality. We need not consider it further.
Davis A. Young (1988, pp.128-131) treats Nevins’ argument in more detail. Another point made by Nevins is that sediment is piling up on the ocean floor faster than it’s being removed. Even if that’s true, there is no reason to view it as being anything more than a temporary imbalance.
…it is generally regarded by geologists that the rates of erosion at present are relatively high because of the topography of the continents. The continental land masses are believed to be much more rugged and mountainous than is usually the case, and mountainous topography speeds up rates of erosion. Thus at the present time we ought fully to expect that more sediment is being added to the oceans than is being removed. Paleogeography indicates that very often in the past the opposite was the case.
Thus, we have no problem from that quarter either.