[X] My Assistant

[Phillip]

Back on August 14, Squyres said:

"We're done with our work in the Voltaire region, having just finished up a pretty thorough IDD investigation of a rock called Assemblee. This thing turned out to have a crazy composition, with by far the highest levels of chromium that we've ever seen on Mars."

Does anyone have any thoughts on what the high levels of chromium tell us? Not being a geologist, I tried to investigate via googling, but came up empty. I would be interested in hearing some thoughts, conjectures or theories.

[CosmicRocker]

Does anyone have any thoughts on what the high levels of chromium tell us?

As has been suggested, there is no simple answer to your very good question. Various elements can become a part of a rock when it initially forms, or they can be introduced/removed at some later time in the rock's history. Without knowing a lot more about this particular rock it would be difficult to speculate on the meaning of elevated chromium levels.

Being one of the transition metals in the periodic table, the chromium ion can behave quite differently in the environment, depending on its oxidation state. For example, it might suddenly become more soluble or insoluble with a relatively small change in local conditions.

Perhaps someone with a better understanding of the behavior of Cr in in rocks can improve on my comments.