>Now we're getting to what JAW's article is asking for - any
>other method that could have produced that much (not a
>percent of) weathering. Does anybody have one?
Take the "precipitation induced weathering" erosion process take out the dominant weathering mechanism of dissolution of calcite and replace it with a dominant weathering mechanism of salt exfoliation. What role does rainwater play in salt exfoliation.... it acts as a source of moisture for the leaching of salt from the rock, transports salts away from salt rich areas so they can be deposited on other surfaces in other beds increasing the influence of salt exfoliation, and it erodes the weathered surface of the rock exposing fresh surfaces to the atmosphere so that salt exfoliation can continue. Salt exfoliation is also a "PI-weathering" erosion process.... salt exfoliation does not need rain to occur so the rates of weathering are considerably higher thab that of dissolution.
You see in order for these extremely ancient Sphinx claims to have any underlying validity the slowest possible weathering mechanism must be in operation (i.e. dissolving calcite by rainwater) and everything else is superficial. We already know these rocks are susceptible to salt exfoliation. What % of the erosion of the Sphinx is the result dissolution of calcite?
> - Laird