> I have, and still do, discount earthquakes as the reason for
> the absence of blocks on any pyramid. Why would there still be
> blocks at the apex but not lower down? As well, many of these
> blocks were not just rectangular in shape, but were L-shaped
> and interlocked, specifically to bind the whole structure
> As well, poorly equipped Arab pilferers with donkeys for
> transport would not have chosen large stones to scavenge.
I don't know, of course.
The initial shock wave from an earthquake would tend to hit the casing stones on the opposite side of the origin the hardest and be nearly as destructive to the near side. I believe the large areas on the bottom could well be more susceptile to damage since the only thing to support them are corners which are farther away. Secondary shaking would normally tend to be hardest at the top.
Looking at the pyramid I'd just guess the north and south sides were badly damaged and partially collapsed in the initial wave and damage was fairly even but much lighter in the secondary shaking. I'm further guessing men scaled the badly damaged corners knocking off stones as they went to access as much altitude as possible. Once they got as high up as was safe they went along the casing stone horizontally and pried off stones. They proceded this way to the bottom.
It would have been exceedingly difficult to remove these stones at all unless there was damage since scaling the corners would be so risky.
I would agree that the means by which they were removed is much more apparent than that there existed significant damge beforehand.