[X] My Assistant

[Ant103]

The view toward Beagle is more and more precise.
http://origin.mars5.jpl.nasa.gov/gallery/a...CNP2435R2M1.JPG
The crater place seems to be a bit complex.

[chris]

Looks like lots of chunks lying around. Its going to be very interesting to see how they have interacted with the sand du, er ripples. Which leads me to another thought...

There have been lots of discussions on the tiny craters, etc, and whether they are caused by sapping or are tiny impact craters. I've been puzzling over this for ages (I'm not a geologist, btw). It seems to me that the dunes must be static now, otherwise the wind that we know blows over the plains would fill in the craters by moving the sand. They must have been mobile at some point, otherwise they wouldn't have the wind-sculpted shapes. This means they *must* have been mobile at one point.

I'm finding it hard to understand how slow hardening could result in preservation of the ripple shapes, so it ocurred to me that it might not have been so slow. We know that the apron of Victoria is splash-like, which might imply water. So perhaps the impact released a cloud of water vapour that interacted with the very fine, very dry sand, and essentially fixed it in place.

Am I talking nonsense?

Chris

[dvandorn]

I mentioned this in the "Moving South to Victoria" thread, Gary. I see it that way, too -- but I was concerned that I was seeing the contact wrong. The fact that it looks that way to you, too, makes me feel a little better.

It really does appear that the hillock overlays the ripples, doesn't it? Question is, does the entire hillock overlay ripples, or has the hillock just crumbled and slumped on top of ripples that are, indeed, more recent than the emplacement of the main body of the hillock?

-the other Doug