One plan I've seen for ISRU on the moon is to use a Al-Lox hybrid engine, since Al2O3 is all over the moon's surface. I wonder if there's enough on Mars to do

One plan I've seen for ISRU on the moon is to use a Al-Lox hybrid engine, since Al2O3 is all over the moon's surface. I wonder if there's enough on Mars to do the same thing, or if you could do something with iron oxide.