> Right. JAW and Schoch argue that the huge amount of
> weathering implies a huge amount of moisture. Your argument
> gets to the same place - to produce that large (12 feet) an
>effect, you need a lot of water.
Not necessarily... rates of erosion are directly controlled by the rates of weathering (if the rocks are not weathered it can rain all it wants and little erosion is going to occur). Salt exfoliation can be independent of rainfall, so when it rains erosion occurs in rocks that are already weathered and susceptible to wasting of this loose material away from the outcrop. The amount of water needed to produce a given erosion is dependent on how much the rock is weathered to begin with (i.e. a deeply weathered surface requires a smaller amount of rainfall to erode). Rates of salt exfoliation are considerably higher than that of dissolution of calcite (which requires rainwater to both weather and waste at the same time to produce the erosion morphology) so the amount of water is less in the case of salt exfoliation as a dominant weathering mechanism.
Archae Solenhofen (firstname.lastname@example.org)
> - Laird