[X] My Assistant

[tdemko]

Every time a see a yet closer image of the outcrop at Meridiani Planum, I hear this Krusty the Clown voice in my head saying: "What the hell was that?!?!?"

I've just about given up speculation on the origin of this stuff. But not quite...

Close-ups like this:

http://www.lyle.org/mars/imagery/1M1295157...33M2M1.JPG.html

continue remind me of textures and fabrics I've seen in travertine and sinter deposits, except for those spheres imbedded in it. In the first Navigation Camera images, while still on the lander, the outcrop looked like bedded clastic rocks (e.g. sandstone). As the rover got closer, both the PanCam and NavCam images looked more like ratty welded tuff (volcanic ash). Now, when the rover is right up against the rock, it looks like a chemical precipitate! And the roundy things are definitely a lag weathered out from whatever this stuff is.

It will be nice to get some close-up spectrometry for some idea of composition. No one has said carbonate or silica out loud yet, but I wonder...

If the spheres are the source of the hematite, what could the host rock possibly be?
---
Tim Demko
http://www.d.umn.edu/~tdemko