[X] My Assistant

[dvandorn]

First, a few words about Endurance... it features several spots along the inner wall where scalloped edges of the rim have fallen into "slump blocks" halfway down the wall, right? We've seen several of them in the pans of Endurance.

We also see some terraces along the rim which display undersapping of soil beneath what are obviously five to ten foot thick layers of evaporite rock.

The rim has been degrading over millions of years, as underlying soil has been eroded away and layers of evaporite rock have come sliding into the crater's inner walls.

Now, look at an image of the Keratepe entrance path to Endurance:

http://marsrovers.jpl.nasa.gov/gallery/pre...rive-B150R1.jpg

Note how the edge of the primary contact between apparently evaporite rock and what lies below seems to scallop into the crater, rather than follow the curve of the crater itself. In other words, if the rim of the crater defines a concave curve, the edge of this layering unit seems to define a convex curve.

And there seems to be this little raised rimlet of exposed evaporite-appearing rocks right at the edge of this convexly-curved bedding.

It looks to me for all the world like Opportunity is traveling along the edge of a ledge that collapsed into the crater. Instead of looking at really, really deep layering of the underlying units, all of the evaporites in view look to me like they're shattered remnants of an evaporite "terrace" unit that collapsed into the crater a while back. So, instead of a beautifully layed-out series of in-place bedrock layers, we may well be looking at the partially-coherent, partially-jumbled talus of an infall of a layer that seems to be about five to ten feet thick at other points along the rim wall, but here is spread out by its slump to cover forty or fifty linear feet, all told.

Does anyone see what I'm seeing here?

Doug
dvandorn ((New Address To Be Announced))