So you are saying oxygen doesn't oxidize?

It does but the neutral molecular oxygen will oxidize less than an ionized oxygen molecule (or most any ionixed molecule for that matter). It's called electro(-)negativity and means a molecule's affinity for electrons. Neutral oxygen really likes electrons but any molecule missing an electron from it's usual neutral configuration is much more attractive, I assure you.

The huge difference here Barry is the ultraviolet doing the charge seperation and the lack of an atmosphere dense enough to unseperate the charge effectively.

If Mars is as oxidizing as Quinn and Zent put it, then why is there so much magnetic material in the soil?

Maghemite it the low temperature oxidation form of magnetite. It still has 4/5th the possible magnetization of magnetite. The surface of micron and smaller sized particles of magnetite will revert to maghemite to a depth of 10s of nm when exposed to oxygen quickly here or slowly but inexorably on Mars. Nevertheless, the magnetization is for the most part unaffected.

This is another BIG clue that Mars wasn't a wet-warm wonderland. Warm water exposed to the same small particles will usually oxidize into hematite, a mineral with 1/200th the magnetization of magnetite.

Still wanna pretend I'm a bunny, you big bad wolf?