Chemical weathering in high-sediment-yielding watersheds, New Zealand

[1] We have determined the chemical erosion yields for fifteen watersheds in New Zealand, ranging in size from 12.2 to 2928 km. These rates, coupled with previously measured physical erosion yields, allow us to compare these two modes of landscape denudation. The physical erosion yields are some of the highest measured in the world. Although in most instances the chemical erosion yields are only a small fraction of the total erosion yields, the absolute values are very high. Our data strongly support the notion that chemical erosion rates are greatly influenced by the yield of physical erosion and that the rapid production of fresh surfaces as a result of high physical erosion rates and subsequent denudation is critical to the high chemical erosion yields observed.