Nick,

Why did the little grey rocks get pushed so deep in the regolith (or should I call it dust)? That dust seems almost like fluff. If it were like bulldust that's common in the southwest corner of Queensland, the dust would compact and little rocks wouldn't get pushed in. Why is it so different from the MER-A site? I presume the little grey rocks are either composed of hematite or coated with the material. Some of the little grey rocks are almost spherical. It's easy to imagine something like that forming in zero gravity such as chondrules in a meteor. However wouldn't atmospheric interaction prohibit such a formation process within the Martian atmosphere? Since the hematite is localized, we can dismiss the possibility of this being something like a tektite that got belched out of a big volcano. Is it credible that the material is being vented into the atmosphere from something locally? If it was an exposed reef of hematite, I would expect the material to weather off as a fine dust and not as large grains. What's the temperature difference between hematite melting and it chemically decomposing?

Gary