<HTML>Colin!
Wow, nice to hear from you again! And so very nice of you to finally correct your interpretations regarding the behaviour of sheetwash.
> Colin Reader wrote:
>
> 2. On the AMUN discussion site a few weeks ago a 1920/30
> aerial photo was posted - this was very revealling (Mikey may
> be able to provide a link???). It showed the Great Pyramid
> and the area to the south (between the GP and Khafre's
> Causeway- which was out of shot). The photo showed a number
> of quite well incised drainage channels - I wondered about
> these channels for a while and then realised what was
> probably going on (it's an oblique aerial photo so at times
> it's hard to correlate the features with a plan but I think
> I've about got it sussed).
>
> The channels rise in the unquarried areas of the plateau -
> the area around the GP itself (probably including water shed
> off the pyramid) and off the unworked areas between the
> pyramids of Khufu and Khafre.
>
> When they encounter the backfilled quarries they begin to cut
> down into the loose backfill as would any river or water
> course moving from hard to soft materials. By the time the
> channels have developed in the east (ie 'behind' the Sphinx)
> they have cut a good way down into the backfill - probably
> limited by the limestone at the base of the quarry.
Can you now understand my argument regarding the behaviour of running water? It doesn't flow as sheetwash for any distance at all. It forms channels!!!!!! If it is what eroded the walls of the enclosure, why didn't it cut them by forming channels instead of cutting the entire wall at the same pace (which is what is so very evident from the aerial photos)?
Anyway, nice to hear from you again. We seem to have the ability to be ascerbic, yet remain civil at the same time! Kat will be pleased.</HTML>